Home

Excelsior - Spectra

1. nity Standard Immunity to conducted disturbances induced by radio frequency fields EN 61000 4 8 1993 A1 2001 Electromagnetic Compatibility EMC Testing and measurement techniques Power frequency magnetic field immunity test EN 61000 4 11 1994 A1 2001 Electromagnetic Compatibility EMC Part 4 Test ing and measurement techniques Voltage dips short interruptions and voltage variations immunity tests EN 61000 6 2 2001 Electromagnetic Compatibility EMC Immunity for industrial environments EN 61000 6 4 2001 Electromagnetic Compatibility EMC Emission standard for industrial environments 73 23 EEC 1973 Low Voltage Directive EN60825 1 1994 A1 2002 A2 2001 Cor 2004 Safety of laser products Equip ment classification requirements and users guide EN60950 2001 A11 Cor Safety of Information Technology Equipment including electrical business equipment EN 61010 1 2001 Cor 1 2 General requirements Safety requirements for electri cal equipment for measurement I the undersigned hereby declare that the equipment specified above con forms to the above Directives and Standards Bruce Craig Vice President Spectra Physics Newport September 6 2005 Laser Safety Sources for Additional Information Laser Safety Standards Safe Use of Lasers Z136 1 American National Standards Institute ANSI 11 West 42 Street New York NY 10036 Tel 212 642 4900 Occupational Safety and Health Admi
2. tion of v In this way the population of E is kept large and that of E remains low thus establishing a population inversion between E and E Under these conditions light is amplified as it passes through the material which is now a gain medium ES A Eg Z E1 Figure 3 1 A Typical Four level Transition Scheme System Description Resonant Optical Cavity and Cavity Modes Most laser materials must be placed in a resonant optical cavity to achieve useful levels of amplified light This cavity is typically two mirrors placed facing each other to form a resonator that reflects light back and forth through the gain material that is placed between them Both resonator mir rors are coated to reflect the laser wavelength thus containing it within the cavity while transmitting all others and thus removing them from the cav ity As the reflected light passes through the gain material stimulated emission produces two photons The two photons are trapped in the resonator and are reflected through the gain to become four four become eight and the numbers continue to increase geometrically until an equilibrium is reached where the excitation rate and emission rate of the gain medium are equal The light in the resonator forms standing waves with frequencies that depend on the resonator design Standing wave frequencies that are ampli fied in the gain material form the circulating light in the cavity This is the energy
3. Every effort has been made to ensure that the information in this manual is accurate All information in this document is subject to change without Excelsior Diode Pumped Visible CW Lasers notice Spectra Physics makes no representation or warranty either express or implied with respect to this document In no event will Spectra Physics be liable for any direct indirect special incidental or consequential damages resulting from any defects in this documentation Finally if you encounter any difficulty with the content or style of this manual or encounter problems with the laser itself please let us know At the end of this manual is a form to aid in bringing such problems to our attention Thank you for your purchase of Spectra Physics instruments CE Environmental Specifications CE Electrical Equipment Requirements For information regarding the equipment needed to provide the electrical service requirements listed in Table 3 4 on page 3 12 please refer to speci fication EN 309 Plug Outlet and Socket Couplers for Industrial Uses listed in the official Journal of the European Communities Environmental Specifications The environmental conditions under which the laser system will function are listed below Indoor use Vibration Laser Head Temperature Maximum relative humidity Controller Temperature Maximum relative humidity Insulation category Pollution degree 1 5 m sec 0 15 G 15 Hz
4. it can be seen that reducing the separation between the resonator mirrors will increase the frequency spacing of the longitudinal modes and sometimes enable only a single mode to remain within the gain bandwidth of the laser material Often however the gain bandwidth is so large that the mirror separation would have to be impracti cally short to result in only a single mode remaining Although the Excel sior lasers are very small they still produce numerous longitudinal modes due to the broad gain bandwidth of the neodymium based crystals A variety of means exist to eliminate all but one longitudinal mode in such a case including the insertion of an etalon into the resonant cavity An eta lon is type of resonator and in its simplest form is just a thin flat piece of glass resembling a microscope slide Placed intracavity the mode separa tion of this thin element will limit the modes allowed to resonate Nd as a Laser Medium 3 4 The output of one laser can be used to excite or pump the gain medium of another laser e g a diode laser can be used to pump a solid state laser The Excelsior lasers use a diode laser to pump Nd ions added to either a crys tal of yttrium vanadate Nd Y VO or yttrium aluminum garnet Nd YAG The properties of neodymium doped crystals are the most widely studied and best understood of all solid state laser media The four level Nd YAG ion scheme is shown in Figure 3 3 The active medium is
5. maximization of this overlap is often called mode matching and in most applications TEMo is the laser mode that is most desired A longitudinal pumping geometry provides this sort of optimal mode match Longitudinal pumping allows the diode laser output to be focused on a vol ume in the active medium that best matches the radius of the TEM o mode In general the TEM mode radius is chosen to be as small as possible to minimize the solid state laser threshold Figure 3 5 shows a schematic of a mode matching design of this type Diode Laser Mode Volume TEMoo Mode Volume Z Gain Region E Lasing Medium Figure 3 5 Mode Matching Frequency Doubling System Description In the Excelsior the infrared output a neodymium based laser crystal is converted to visible light through frequency doubling also called second harmonic generation in a nonlinear crystal Frequency doubling occurs when an intense laser beam enters a nonlinear crystal and generates a sec ond beam at half the incident wavelength The blue Excelsior lasers use a lithium triborate LBO crystal as the doubling medium the green lasers use a potassium titanyl phosphate KTP crystal Phase matching is a requirement of nonlinear optics to achieve an efficient conversion of the fundamental incident light to a new wavelength To pro duce any significant output at the new wavelength the fundamental light wave and the converted light wave must sta
6. 200 Hz 10 C to 40 C lt 80 non condensing over allowed temperature range 10 C to 45 C lt 90 non condensing over allowed temperature range II 2 Table of Contents PIECE rar ar ada dad a abad ara iii CE Environmental Specifications 0000 cece ee V CE Electrical Equipment Requirements 0 0 0c rn V Environmental Specifications o oooococooocooo een en V Warning Conventions 2 d die 2 RC AA RU V C e xi Standard Units gie wood us tee xiii Unpacking and Inspection eeellllleeee nn nn nenn XV Unpacking Your Laser a c ai da WAWA ERA SE NEG t ERR E RE MT e Drill XV System Components 34 209 san ne ERA an ae A a bboy EEN BA XV ACCESSOTIOS Hain G RA a B OO death z Qu aed And SE ee XV Chapter 1 Introduction 2a Ru a a a a WE ETE EC 1 1 Patents c ar nr sae heeled Aaa Pa A het RATE ten I ERU E 1 2 Chapter 2 Laser Safety is ore na rin 2 1 Precautions For The Safe Operation Of Class Illb High Power Lasers 2 1 Safety Devices cuina rd cR ead a Aaa E buh ied bb xg db Ed Sets 2 3 Easer Power On Control wa ne RD E UR Erg Saha ika BEA HN 2 3 Internal External Control Switch 2 4 Laser Emission INdICAtOF o 54 NIK te eR ep eH EE DU Obs dee ER RW BR TERES 2 4 Safety Int rlocKs tee dace ha ed ger an bx pa de ee od ss xad dob rw p 2 4 Maximum Emission LevelS hr re 2 4 Requirements for Safely Operating the Excelsior Laser System with a User provided
7. damaging to optical surfaces and coatings and can lead to serious degradation problems under intense laser illumination It is therefore essential that only clean items come into contact with optical components and to the mechanical parts immediately surrounding them Service Training Programs Excelsior lasers are designed for hands off operation This product does not require alignment nor routine cleaning of cavity optics Service is generally limited to replacing the entire laser head Spectra Physics offers service training programs to train personnel in the diagnosis of problems Excelsior Diode Pumped Visible CW Lasers Troubleshooting This troubleshooting guide is intended to assist you in isolating some of the problems that might arise while using the system For information concern ing the repair of this unit please call your Spectra Physics representative A list of world wide service sites is included at the end of this chapter Symptom No laser beam Possible Causes Corrective Action No On signal applied to the controller Improper power supply volt age Loose cable connector Improper settings for the INTERNAL EXTERNAL switch Pin 2 of the EXTERNAL CONTROL connector must be pulled to ground to turn on the laser If the laser power is controlled externally set the INTERNAL EXTERNAL switch to EXT and provide a stable low noise 5 V signal to Pin 8 of the EXTERNAL CONTROL connector Verify the DC p
8. diode pump laser The scale is 100 mV Amp the maximum signal is 160 mV corresponding to 1 6 A 5 Output Laser Power Monitor Pin 5 provides an output signal that is approximately pro portional to the power output of the laser At full output power the signal is 95 100 mV Example a Pin 5 signal of 50 mV for the Excelsior 473 10 indicates that laser power has fallen to about 5 mW 6 Ground 7 Ground 8 Input External Power Control This pin is used to vary the output power of the Excelsior 532 100 and the Excelsior 532 150 This pin works only for these two models Refer to Changing the Laser Output Power on page 4 9 for directions on using this input 9 N A Reserved Must be open 10 Output Diode Laser Alarm Indicates the diode pump laser in the laser head is nearing its end of life To employ this open collector alarm refer to Figure 4 9 for an example of this circuit 11 Ground 12 Ground 13 N A Reserved Must be open 14 N A Reserved Must be open 15 N A Reserved Must be open Installation and Operation Operation Please read this entire chapter and Chapter 2 Laser Safety before turn ing on the Excelsior laser for the first time Danger The Spectra Physics Excelsior laser is a Class IIIb High Power Laser As whose beam is by definition a safety hazard Take precautions to prevent accidental exposure to both direct and reflected beams Diffuse as well as specular beam reflections can cause severe e
9. electrons then make the reverse transition to the upper laser level Nd YAG exhibits the same effect but thermal population of the lower laser level is less so the blue Excelsior lasers employ YAG crystals to produce the 946 nm wavelength for doubling to 473 nm Self absorption can also be reduced somewhat by carefully engineering the diode pump design Diode Pumped Laser Design Diode lasers combine very high brightness high efficiency monochroma ticity and compact size in a near ideal source for pumping solid state lasers Figure 3 4 shows the emission spectra of a diode laser compared to a black body source The near perfect overlap of the diode laser output with the Nd absorption band ensures that the pump light is efficiently coupled into the laser medium Any pump light not coupled into the medium must ultimately be removed as heat 3 5 Excelsior Diode Pumped Visible CW Lasers Nd3 Absorption A 0 5 0 6 07 0 8 0 9 Wavelength um __ Black Body Source 3000 K oo Diode Laser Pump Wavelengtl Emission Intensity 0 6 07 08 0 9 Wavelength um o a Figure 3 4 Nd absorption spectra compared to emission spectra of a Black Body Source a and a Diode Laser b One of the key elements in optimizing the efficiency of a solid state laser is maximizing the overlap of the regions of the active medium excited by the pumping source and the active medium occupied by the laser mode The
10. frequency doubling is given by PLA 2 A where d pis the effective nonlinear coefficient P is the fundamental input power I is the effective crystal length 9 is a phase matching factor and A is the cross sectional area of the beam in the crystal P 4 The important point to note from equation 4 is that the second harmonic output is dependent upon the square of the fundamental peak power High conversion efficiencies can therefore be achieved by placing the doubling crystal within the laser resonator itself called intracavity frequency dou bling to take advantage of the high circulating intensity This is the opti cal design used in the Excelsior 3 7 Excelsior Diode Pumped Visible CW Lasers The Excelsior Lasers An Excelsior system comprises one of seven models of the laser head together with the controller interface that routes electrical power control and monitoring signals between the OEM laser head and the master sys tem All of the Excelsior lasers operate at constant power in addition the three high power green models allow the option of varying the output power using an external control signal The Excelsior Laser Head 3 8 Note The Excelsior laser head provides maximum reliability with minimum complexity and size The inherent operation is so stable and the output so quiet that no adjustments are needed in normal operation Laser Cavity Design The Excelsior uses a compact linear cav
11. ionized neody mium which has principle absorption bands in the red and near infrared 20 Pump Bands 18 16 F S AE 1 14 L a ee Ra AA 11414 R 49 Laer d Laser Fea 2 7 Transition 10 L Laser Fae Z Transition v 6000 cm 1 Be e ut 4000 cm 1 6 li5 2 er A S 2526 _ eU apu 2473 4 L hse if Be Le QS 2111 2 am 2029 2 4l11 2 Y 2001 ED 848 E az eam 22 Ground Level 16 0 Figure 3 3 Energy Level Scheme for the Nd Ion in YAG System Description The electrons in the neodymium ions are very efficient at absorbing the diode laser light that excites them to the pump bands shown in the figure The excited electrons quickly drop to the F y level the upper level of the lasing transition where they remain for a relatively long time The most probable laser transition is to the d State which emits photons at 1064 nm Because electrons in that state quickly relax to the ground state the population of this state remains low Hence it is easy to build a population inversion where the number of electrons in the higher energy level exceeds the number in the lower level There are several different laser transitions in neodymium that start from the same upper state These transitions compete for the same population of electrons and left to themselves the 1064 nm transition will dominate The blue Excelsior lasers employ vanadate Nd Y VO crystals
12. laser head to power the diode pump laser Conse quently a reliable means must be provided to remove waste heat from the controller in addition to the laser head Follow standard practice to mount the controller on a heatsink with a ther mal impedance of no greater than 2 C W Installation and Operation Installing the Hardware Mount the Laser Head Follow standard practice to mount the laser head on a suitable heatsink as described in the preceding section Use four M3 or 4 40 screws and washers to mount the laser head using the mounting holes shown in Figure 4 3 lt L4 gt 9238 gt Lo gt Dimensions given in inches f g Umm ua 1 102 28 0 U Beam Exit Aperture l Beam Height 0 748 HE 19 0 0 217 1 437 Q RE Se 5 5 36 5 b Y t 0 138 35 lt L3 S g 0 118 10 001 99 ati a bl 0 787 Pa 20 0 Ho 44 g 0 138 P i e GES 0 118 10 001 0 157 3 0 X 40 Length Excelsior Model L4 Lo L3 532 150 532 100 532 50 3 74 in 95 0 mm 3 23 in 82 0 mm 3 47 in 88 0 mm 532 20 532 10 473 5 473 2 3 33 in 84 5 mm 2 83 in 71 5 mm 3 05 in 77 5 mm Figure 4 3 Excelsior Laser Head Outline Drawing Note the location of the precision alignment holes in the laser head base plate The boresight specifications are with respect to the axis of these holes Note that the beam height is located 19 mm ab
13. on the Excelsior Controller uaaaaaaaaaa aaa aaa aaa aaa nn 2 3 Figure 2 4 Interlock Jumper Plug 2 3 Figure 2 5 Excelsior Radiation Control Drawings 2 6 Figure 2 6 Warning Labels 2 7 Figure 3 1 A Typical Four level Transition Scheme 3 2 Figure 3 2 Frequency Distribution of Longitudinal Modes 0 cee eee 3 3 Figure 3 3 Energy Level Scheme for the Nd lon in YAG uueaaaaa aaa aaa esee 3 4 Figure 3 4 Nd absorption spectra compared to emission spectra of a Black Body Source a and a Diode ER LE 3 6 Figure 3 5 Mode Matching 3 6 Figure 3 6 Interlock Jumper Plug 3 9 Figure 4 1 Heat Dissipation of the Laser Head 4 2 Figure 4 2 Laser Head Heatsink Thermal Impedance for 50 C Baseplate Temperature 4 2 Figure 4 3 Excelsior Laser Head Outline Drawing 4 3 Figure 4 4 Excelsior Controller Outline Drawing llllllel II 4 4 Figure 4 5 Excelsior Controller Connections aaa aaa aaa 4 5 Figure 4 6 External Control Connector Pin Numbering 222202 aaa aaa aaa aaa nn 4 6 Figure 4 7 Laser On Off Control Example L auauaaaaaaaaaaaawa en 4 7 Figure 4 8 Laser Emission Indicator Example 4 8 Figure 4 9 Diode Laser Alarm Example 4 8 Figure 4 10 Interlock Jumper Plug 4 9 List of Tables Table 1 1 Green Excelsior Laser 1 2 Table 1 2 Blue Excelsior Laser 1 2 Table 2 1 Maximum Emission Levels 2 4 Table 2 2 Label Translations sas a rare ea NER ERG 2 8 T
14. operation of a laser incorporated into that product Safety Devices Laser Safety Cable wo I Laser Head Cable Connector Power Supply Connector Internal External Control Switch Figure 2 3 Safety Devices on the Excelsior Controller There are no safety devices no indicators shutter or power controls on the laser head itself All control and monitoring of laser functions is through the EXTERNAL CONTROL connector on the controller Laser Power On Control The Excelsior laser turns on when current is available to the diode laser in the laser head and a suitable control signal is applied to Pin 2 of the EXTERNAL CONTROL cable connector on the controller Laser output begins immediately when these conditions are met A interlock jumper plug is provided with the system to allow operation without an external control cable Figure 2 4 Interlock Jumper Plug 2 3 Excelsior Diode Pumped Visible CW Lasers Internal External Control Switch This switch provides the option to control the level of the laser output of the Excelsior 532 50 the Excelsior 532 100 and the Excelsior 532 150 Control is by means of an analog signal applied to Pin 8 on the EXTERNAL CONTROL connector see Chapter 4 for details on how to use this option All other models of the Excelsior laser are pre set at the factory to their maximum specified output power Laser Emission Indicator Safety Interlocks Pin 1 of the EXTERNAL CONTROL connecto
15. side of the controller to EXT Be certain that the EXTERNAL INTERNAL CONTROL switch is set to INT for all other Excelsior models or when the three high power green lasers are meant to operate at full and constant power The lasers will not operate if this switch is mistakenly set to EXT The power level can be changed between 50 and full power by changing the voltage on Pin 8 between 50 mV and 100 mV For the Excelsior 532 50 output varies from 25 mW to 50 mW for the Excelsior 532 100 from 50 mW to 100 mW for the Excelsior 532 150 from 75 mW to 150 mW Operating the laser below 50 of its rated power is not recommended Note sj The full set of Excelsior specifications are guaranteed only at the 100 power level As is the case with the other Excelsior models these three high power green Excelsior lasers will operate at constant power when the EXTERNAL INTERNAL CONTROL switch is set to INT Interlock Jumper Plug Danger Laser Radiation A interlock jumper plug Figure 4 10 is provided with the system to allow operation without an external control cable Note that when power is supplied to the laser the laser will come on immediately when the jumper plug is inserted into the External Control connector of the controller Figure 4 10 Interlock Jumper Plug Excelsior Diode Pumped Visible CW Lasers 4 10 Chapter 5 Danger Laser Radiation Eyewear OBA Required Maintenance Troubleshooting
16. 0 mW at 473 nm All are designed to operate at constant output power The three higher power green lasers allow the operator to vary laser power via the controller interface The different models are summarized in Table 1 1 and Table 1 2 on page 1 2 These lasers deliver efficient stable light with excellent spatial mode that is critical for applications in graphics photo finishing and flow cytometry Individual Excelsior models operate in either single or multiple longitudinal mode Again refer to Table 1 1 and Table 1 2 The Excelsior laser heads come in two sizes that are approximately 8 5 and 9 5 cm in length The heads are designed for precision mounting and alignment of the beam which together with the specified boresight of the output simplifies the task of designing the master optical train or replacing a laser head in the master system All of the optical components including the diode pump source are contained in the laser head itself 1 1 Excelsior Diode Pumped Visible CW Lasers Note Patents 1 2 E The lasers are controlled by the master system by means of analog signals provided through the connector on the small controller All Excelsior models use the same controller Since all Excelsior lasers use the same controller the laser heads are completely interchangeable In case the laser head or the controller needs to be exchanged the new unit is simply fastened in place and the cabling connected No adjustm
17. Control Device 2 5 Schedule of Maintenance in Accordance with Center for Devices and Radiological Health CDRH Regulations auaaaaaaaaaaa aaa eee 2 5 Radiation Safety Control Drawings ernennen 2 6 Warning Eabels ooo herb ROS en Meet wee ah siehe 2 7 Label Translationis o codo EE Ma A reine 2 8 Waste Electrical and Electronic Equipment Recycling Label 2 9 CE Declaration of Conformity oooooccocc aaa mre 2 1 Sources for Additional Information ooooococcocooo aaa e 2 1 Laser Safety Standards 2 1 Equipment and Training 0 0 AE ARE RR hh 2 1 vii Excelsior Diode Pumped Visible CW Lasers Chapter 3 System Description oooooooooccnnnc nun nn nn 3 1 A Brief Review of Laser Theory 3 1 Emission and Absorption of Light 0 cece nh 3 1 Population Inversion llli rrr 3 2 Resonant Optical Cavity and Cavity Modes Laaaaaaaaaaaaaaaaa aaa rens 3 3 Single Longitudinal Mode Operation 3 4 Nd 35 4 Laser Medi cues ox daa bud eee NK bens Pr dest pd abe is i 3 4 Diode Pumped Laser Design oooococoocc rn 3 5 Frequency Doubling im ce RR eR Rx ae Pee E Ere dre ren 3 7 Ihe Excelsior Lasers sien Z i ee Satie eee wane eke ULM he 3 8 The Excelsior Laser Head 3 8 The Excelsior Controller LL auaaaaaaaaaaaaaaaa aaa mr 3 9 Power Supply Requirements 3 9 Specifications 224540 n A us Qt ege tended nl gdh Gandy Mig Ra des Se lt 3 10 Chapter 4 Installatio
18. Controller Laser Head Cable Length 5 Vdc 10 6 A lt 30 W Air cooled 19 mm 0 75 in 0 3 kg 0 7 Ib 0 25 kg 0 6 Ib 9 50 x 3 65 x 2 8 cm 3 74 x 1 44 x 1 10 in 8 45 x 3 65 x 2 8 cm 3 33 x 1 44 x 1 10 in 13 8 x 3 35 x 9 94 cm 5 30 x 1 32 x 3 91 in 1 m 3 ft Weights are approximate Refer to outline drawings for exact dimensions Cable length is approximate Chapter 4 Installation Warning W Installation and Operation Read this chapter in its entirety before attempting to install and operate the laser Excelsior lasers are OEM devices designed to be integrated into a master system that provides all of the necessary electrical power control signals and regulatory safety features System connections are described below in Controls and Connections An Excelsior laser head is connected to the controller by a one meter long cable that provides on off control of the laser as well as diagnostic infor mation The cable connects to the 15 pin EXT analog port Electrical power for the laser is provided to the controller through the 9 pin POWER connector To provide a margin of safety select a cable capable of carrying at least a 10 Amp current to connect to the controller Because of the high initial current draw make sure that the load is shared between the pins on this connector Refer to Controls and Con nections below Thermal management of the heat load produced b
19. Excelsior Diode Pumped Visible CW Lasers User s Manual This laser product is intended to be sold to a manufacturer of OEM products for use as a component or replacement thereof in those products As such this product is exempt from performance standards of United States Code of Federal Regulations Title 21 Chap ter 1 Food and Drug Administration De partment of Health and Human Services Subchapter J Parts 1040 10 a 1 or 2 G Spectra Physics A Division of Newport Corporation 1335 Terra Bella Avenue Mountain View CA 94043 Part Number 0000 347A Rev A September 2005 Preface This manual contains information you need in order to safely install operate and service your Excelsior diode pumped visible CW laser An Excelsior system consists of one of seven different models of laser head that produce either green or blue laser light together with the Excelsior controller The controller is a small stand alone unit that provides basic control and monitoring functions for the laser All of the different models of the Excelsior make use of the same controller without modification Excelsior is designed to be an OEM product and all power and command signals are intended to be provided by a master system to the laser through the controller Chapter 1 Introduction contains a brief description of this laser system its components and patent information Chapter 2 Laser Safety is require
20. able 3 1 Excelsior Green Laser Output Specifications aaa eee 3 10 Table 3 2 Excelsior Blue Laser Output Specifications 3 11 Table 3 3 Environmental Specifications 3 12 Table 3 4 Electrical Mechanical Specifications aaaaaaaaaaaaaaaa aa aaaa ee 3 12 Table 4 1 External Control Connector Pin Functions uaaaaaaaaaaaaaaa aaa aaa nenn 4 6 Table 5 1 Replacement Parts 5 4 Excelsior Diode Pumped Visible CW Lasers Danger Laser Radiation Danger Danger Warning Warning ESD Caution Note Don t Touch Eyewear Required d W U W V 8 ZA Warning Conventions The following warnings are used throughout this manual to draw your attention to situations or procedures that require extra attention They warn of hazards to your health damage to equipment sensitive procedures and exceptional circumstances All messages are set apart by a thin line above and below the text as shown here Laser radiation is present Condition or action may present a hazard to personal safety Condition or action may present an electrical hazard to personal safety Condition or action may cause damage to equipment Action may cause electrostatic discharge and cause damage to equip ment Condition or action may cause poor performance or error Text describes exceptional circumstances or makes a special refer ence Do not touch Appropriate laser safety eyewear should be worn during t
21. and Service The Spectra Physics Excelsior lasers are Class IIIb High Power Lasers whose beams are by definition a safety hazard Take precautions to prevent accidental exposure to both direct and reflected beams Diffuse as well as specular beam reflections can cause severe eye damage Always wear proper eye protection when working on the laser and fol low the safety precautions in Chapter 2 Laser Safety The Excelsior laser head requires no routine maintenance Do not remove the outer cover there are no user serviceable parts inside the laser head This cover should only be removed by an authorized service engineer To retain a clean intracavity environment all components are cleaned to stringent standards prior to assembly and alignment at the factory The cover of the laser module inside the laser head is secured and sealed and should never be opened Removing the module cover will compromise the cleanliness of the intracavity space degrade laser performance and void the warranty Replacing the diode pump laser can only be performed at a Spectra Physics facility by someone trained and authorized by Spectra Physics Call your Spectra Physics service representative when you suspect that the diode pump laser is at its end of life AII parts that normally come in contact with laboratory or industrial envi ronments retain surface contamination that can be transferred to optical components during handling Skin oils can be very
22. as well using them to create conditions favorable for light amplification The following paragraphs describe these conditions A material in thermal equilibrium has most of its atoms or molecules in their ground state As a result the rate of absorption of incident light at all frequencies exceeds that of emission If enough light at the correct frequency v is supplied electrons in a lower energy level will absorb light energy and shift to an upper level until the populations of two levels are equal N N For transition between two lev els N can never exceed N because every upward transition is matched by one in the opposite direction However if three or more energy levels are involved in the transition a population inversion can occur where N gt N A model four level laser transition scheme is depicted in Figure 3 1 A photon of frequency v excites or pumps an atom from E to E If the E to E transition probability is greater than that of E to E and if the life time of an atom at E is short the atom will decay almost immediately to E If E is metastable i e electrons occupy it for a relatively long time the population will grow rapidly as excited electrons cascade from above The E electron will eventually decay to E emitting a photon of frequency v Finally if E is unstable its electrons will rapidly return to the ground state E keeping the population of E small and reducing the rate of absorp
23. baseplate If it is below 10 C or exceeds 50 C verify the ambient temperature is within the allowable operating range and correct if necessary Verify the laser head baseplate is properly heat sinked Ensure that light reflected from any external optical elements does not reflect back through the window of the laser head Contact your Spectra Physics service representative about replacing the laser head Troubleshooting and Service Symptom High optical noise Possible Causes Corrective Action Improper power supply volt Verify the DC power supply voltage is between 4 5 V and 5 5 V and that the age power supply is capable of supplying at least 30 W Loose cable connector Verify all cables are securely connected Improper settings for the Verify the controller INTERNAL EXTERNAL switch is set to INT INTERNAL EXTERNAL If the laser power is controlled externally set the INTERNAL EXTERNAL switch switch to EXT and provide a stable low noise 5 V signal to Pin 8 of the EXTERNAL CONTROL connector Laser is not warmed up Allow the laser to warm up for at least 5 minutes Laser head temperature is Measure the temperature of the baseplate If it is below 10 C or exceeds outside operating range 50 C verify the ambient temperature is within the allowable operating range and correct if necessary Verify the laser head baseplate is properly heat sinked Reflected laser light is desta Ensure that light reflected from any exte
24. d reading before the system is installed and operated The Excelsior lasers are Class IIIb devices and as such emit laser radiation that can cause permanent eye damage Chapter 2 contains descriptions of these hazards and information on how to safeguard against them as well as descriptions of the laser labels and safety devices To minimize the risk of injury or expensive repairs be sure to read this chapter and carefully follow its instructions Chapter 3 Laser Description contains a short section on laser theory regarding the principals used in the Excelsior laser The theory section is followed by a more detailed description of the Excelsior laser that concludes with the specifications for the various Excelsior models Chapter 4 Installation and Operation describes the procedures and requirements for first installing and then operating the laser Chapter 5 Troubleshooting and Service will help guide you to the source of any problems with the laser Do not attempt repairs yourself while the unit is still under warranty instead report all problems to Spectra Physics for warranty repair Customer Service in this chapter gives information on service calls and warranty issues Should you experience any problems with the your Excelsior laser or if you are in need of technical information or support on any issues related to its use refer to the list of world wide Spectra Physics service centers in this chapter
25. e following translations are provided for non English speak ing personnel The number in parenthesis in the first column corresponds to the label number listed on the previous page Table 2 2 Label Translations Label No French German Spanish Dutch Aperture Ouverture Laser Austritt von sichtbarer Por esta abertura se Vanuit dit apertuur Label Exposition Dange und unsichtbarer emite radiaci n l ser wordt zichtbare en 1 reuse Un rayonne Laserstrahlung visible e invisible onzichtbare laserstra ment laser visible et Bestrahlung vermei evite la exposici n ling geemitteerd ou invisible est mis den Vermijd blootstelling par cette ouverture OEM Rayonnement laser Laserstrahlung Radiaci n l ser Laser straling Danger Exposition Dange Bestrahlung vermei Evite la exposici n Vermijd blootstelling Label reuse Appareil a den Producto l ser Clase Klasse 3b laser pro 4 laser de Classe 3b Laser Klasse 3b 3b dukt Puissance maxi Maximale Ausgangs Potencia m xima Max output vermo mum lt 500 mW leistung lt 500 mW gen lt 500 mW Golf Longueur d onde lt 500 mW Longitud de onda lengtebereik 532 nm 473 nm Wellenl nge 532 nm 473 nm 532 nm 473 nm 532 nm 473 nm Patent Ce produit est fabri Dieses Produkt Este producto esta Dit product is gefabri Label qu sous l un ou plu wurde unter Verwen fabricado con una o ceerd met een of 7 sieurs des brevets suivants des Etats Unis dung einer oder meh r
26. ectral Linewidth 0 5 nm 10 MHz 0 01 pm IR Power lt 5 uw 10 uW Beam Characteristics Spatial Mode TEM Beam Quality M lt 1 1 Polarization gt 100 1 Beam diameter e points 0 11 0 01 mm 0 32 0 02 mm optional 0 32 mm Beam divergence full angle lt 7 4 mrad lt 2 5 mrad optional lt 2 5 mrad Beam Ellipticity 0 0 1 0 0 1 Stability Power Stability 12 Warm up Time 5 minutes Optical Noise 0 5 rms 10 Hz 20 MHz 0 2 rms 10 Hz 100 MHz Beam Pointing Stability 20 urad C lt 6 urad C Frequency Drift n a lt 50 MHz C Boresight Tolerance Near field x0 1 mm Far field x0 5 mrad Specifications are subject to change without notice Available in uncollimated and collimated versions see beam diameter and divergence specs The output power of the Excelsior 532 50 Excelsior 532 100 and Excelsior 532 150 can be varied using external con trol all other models operate at constant power 4 Vertical polarization Measured over an 8 hour period after warm up Measured as far field x and y positions after a 5 minute warm up 3 10 System Description Table 3 2 Excelsior Blue Laser Output Specifications 10 mW Excelsior 5 mW Excelsior General Characteristics Power 10 0 x0 2 mW 5 0 0 1 mW Wavelength 473 nm Longitudinal Mode single single Spectral Linewidth lt 10 MHz lt 10 MHz IR Power 1 yw Beam Characteristics Spatial Mode TEM Beam Qua
27. ent or calibration is needed The laser head is specifically designed to facilitate heat removal Electrical power is supplied by the master system only a few Amps at 5 V are required Table 1 1 Green Excelsior Lasers Excelsior Power Longitudinal Head Model 9532 nm Mode Length Excelsior 532 150 150 mw single 9 5 cm Excelsior 532 100 100 mw single 9 5 cm Excelsior 532 50 50 mW single 9 5 cm Excelsior 532 20 20 mW multi 8 5 cm Excelsior 532 10 10 mW multi 8 5 cm l Values are for illustration only refer to Chapter 3 for specified values Available in collimated and uncollimated versions refer to Chapter 3 for specifications Table 1 2 Blue Excelsior Lasers Excelsior Power Longitudinal Head Model 9473 nm Mode Length Excelsior 473 10 10 mW single 8 5 cm Excelsior 473 05 5 mW single 8 5 cm Values are for illustration only refer to Chapter 3 for specified values Excelsior lasers are manufactured under one or more of the following United States patents 4 756 003 4 872 177 5 870 415 3 046 562 Japanese patent Chapter 2 Danger Laser Radiation PA Eyewear Q Required Laser Safety The Spectra Physics Excelsior lasers are Class IIIb High Power Lasers whose beams are by definition a safety and fire hazard Take precautions to prevent accidental exposure to both direct and reflected beams Diffuse as well as specular beam reflections can cause severe eye damage Refer to the
28. er product is intended for OEM use Therefore an application has not been submitted with the Center for Devices and Radiological Health CDRH for compliance review However it is recommended that the same schedule of maintenance be followed as that for systems that comply with these regulations Once a year or whenever the product has been subjected to adverse environmental conditions e g fire flood mechanical shock spilled solvent etc check to see that all features of the product identified on the Radiation Control Drawing on page 2 6 function properly Also make sure that all warning labels remain firmly attached 1 Verify that opening any safety interlock switch used with the system prevents laser operation 2 Verify the laser can only be turned on when the master system key switch is in the on position and that the key can only be removed when the switch is in the off position 3 Verify the user supplied emission indicator provides a visible signal when the laser emits accessible laser radiation that exceeds the acces sible master system emission limits for Class I 4 Verify the time delay between turn on of the user supplied emission indicator and the start of laser emission it must give enough warning to allow action to avoid exposure to laser radiation 5 Verify that when the interlock loop is opened the master system shutter closes and actually blocks laser radiation emission If any of the above items fail to o
29. erer der folgenden US Patente herge stellt m s de las siguientes patentes de los Esta dos Unidos meer van de vol gende USA patenten 2 8 Laser Safety Waste Electrical and Electronic Equipment Recycling Label To Our Customers in the European Union As the volume of electronics goods placed into commerce continues to grow the European Union is taking measures to regulate the disposal of waste from electrical and electronic equipment Toward that end the Euro pean Parliament has issued a directive instructing European Union member states to adopt legislation concerning the reduction recovery re use and recycling of waste electrical and electronic equipment WEEE In accordance with this directive the accompanying product has been marked with the WEEE symbol See label 7 on page 2 7 The main purpose of the symbol is to designate that at the end of its useful life the accompanying product should not be disposed of as normal munic ipal waste but should instead be transported to a collection facility that will ensure the proper recovery and recycling of the product s components The symbol also signifies that this product was placed on the market after 13 August 2005 At this time regulations for the disposal of waste electrical and electronic equipment vary within the member states of the European Union Please contact a Newport Spectra Physics representative for infor mation concerning the proper disposal of th
30. figure will then turn on indicating that the laser is emitting laser light I I PIN 1 5 V I Laser Emission Indicator Laser Emission OK I GND Q O GND I I Controller I External Circuit Figure 4 8 Laser Emission Indicator Example Note that the ground pins of the EXTERNAL CONTROL connector are Pins 6 and 7 and Pins 10 and 11 Using the Diode Laser Alarm A circuit to monitor the diode laser alarm is shown in Figure 4 9 below The diode laser alarm is activated on Pin 10 when the drive current reaches 95 of the factory set maximum limit Note that the Pin 10 signal is dis abled for the first 5 minutes after the diode pump laser is turned on while the diode current stabilizes Diode Laser Alarm 5V Diode Laser Alarm Indicator Q PIN10 I I I l I GND GND I Controller N External Circuit Figure 4 9 Diode Laser Alarm Example Installation and Operation Changing the Laser Output Power Caution W The output power of the Excelsior 532 50 Excelsior 532 100 and the Excelsior 532 150 can be varied by external control All other Excelsior models produce constant output power To change the power of the Excelsior 532 50 Excelsior 532 100 or the Excelsior 532 150 connect a voltage to Pin 8 that can be varied from 50 mV to 100 mV Use one of the ground pins of the EXTERNAL CONTROL connector for reference see Table 4 1 Set the EXTERNAL INTERNAL CON TROL switch on the
31. gdom Telephone 44 1442 258100 United States and Export Countries Spectra Physics 1330 Terra Bella Avenue Mountain View CA 94043 Telephone 800 456 2552 Service or 800 SPL LASER Sales or 800 775 5273 Sales or 650 961 2550 Operator Fax 650 964 3584 e mail service spectra physics com sales spectra physics com Internet www spectra physics com And all European and Middle Eastern countries not included on this list And all non European or Middle Eastern countries not included on this list Notes Notes 1 Excelsior Diode Pumped Visible CW Lasers Notes 2 Notes Notes 3 Excelsior Diode Pumped Visible CW Lasers Notes 4 Notes Notes 5 Excelsi
32. ge and correct if necessary Verify the laser head baseplate is properly heat sinked Reflected laser light is desta Ensure that light reflected from any external optical elements does not reflect bilizing the laser back through the window of the laser head 5 3 Excelsior Diode Pumped Visible CW Lasers Symptom Output power is unstable Possible Causes Corrective Action Improper power supply volt age Loose cable connector Improper settings for the INTERNAL EXTERNAL switch Laser is not warmed up Laser head temperature out side operating range Reflected laser light destabi lizing the laser Verify the DC power supply voltage is between 4 5 V and 5 5 V and that the power supply is capable of supplying at least 30 W Verify all cables are securely connected Verify the controller INTERNAL EXTERNAL switch is set to INT If laser power is controlled externally set the INTERNAL EXTERNAL switch to EXT and provide a stable low noise 5 V signal to Pin 8 of the EXTER NAL CONTROL connector Allow the laser to warm up for at least 5 minutes Measure the temperature of the baseplate If it is below 10 C or exceeds 50 C verify the ambient temperature is within the allowable operating range and correct if necessary Verify the laser head baseplate is properly heat sinked Ensure that light reflected from any external optical elements does not reflect back through the window of the laser head Re
33. his opera tion Refer to the manual before operating or using this device xi Standard Units The following units abbreviations and prefixes are used in this Spectra Physics manual Quantity Unit Abbreviation mass kilogram kg length meter time second S frequency hertz Hz force newton N energy joule J power watt W electric current ampere A electric charge coulomb C electric potential volt V resistance ohm Q inductance henry H magnetic flux weber Wb magnetic flux density tesla T luminous intensity candela cd temperature celcius C pressure pascal Pa capacitance farad F angle radian rad Prefixes tera 107 T deci 10 d nano 10 n giga 10 G centi 107 c pico 107 p mega 105 M mill 103 m femto 105 f kilo 10 k micro 109 U atto 10 a xiii Unpacking and Inspection Unpacking Your Laser Your Excelsior laser was packed with great care and its container was inspected prior to shipment it left Spectra Physics in good condition Upon receiving your system immediately inspect the outside of the ship ping container If there is any major damage holes in the container crush ing etc insist that a representative of the carrier be present when you unpack the contents Carefully inspect your laser system as you unpack it If any damage is evi dent such as dents or scratches on the covers etc immediately notify the carrier and your Spectra Physics sales representati
34. is product Excelsior Diode Pumped Visible CW Lasers CE Declaration of Conformity 2 10 We Spectra Physics 1335 Terra Bella Avenue Mountain View CA 94043 United States of America declare under our sole responsibility that the following products Excelsior Low Power CW DPSS Laser manufactured after August 31 2005 meet the intent of EMC Directive 89 336 EEC 2004 C 98 05 for Elec tromagnetic Compatibility and Directive 73 23 EEC 1973 the Low Voltage Directive Compliance was demonstrated to the following Specifi cations as listed in the official Journal ofthe European Communities 89 336 EEC 2004 C 98 05 EMC Directive EN 55011 1998 A1 1999 A2 2002 Industrial scientific and medical ISM radio fre quency equipment radio disturbance characteristics EN 61000 4 2 1995 A1 1998 A2 2001 Electromagnetic Compatibility EMC Part 4 Testing and measurement techniques Electrostatic discharge immunity test EN 61000 4 3 2002 A1 2002 Electromagnetic Compatibility EMC Basic Immu nity Standard Radiated radio frequency electromagnetic field immunity test EN 61000 4 4 1995 A1 2001 A2 2002 Electromagnetic Compatibility EMC Part 4 Testing and measurement techniques Electrical fast transient burst immu nity test EN 61000 4 5 1995 A1 2001 Electromagnetic Compatibility EMC Basic Immu nity Standard Surge immunity test EN 61000 4 6 1996 A1 2001 Electromagnetic Compatibility EMC Basic Immu
35. ity for convenient end pumping of the laser crystal The diode pump laser in the Excelsior laser head is sometimes referred to simply as the diode in this manual e g when we refer to the diode current The infrared light generated by the laser crystal is intracavity frequency doubled to produce either green or blue output that is the output of a van adate crystal at 1064 nm is doubled to 532 nm in the green lasers and the output of a YAG crystal at 946 nm is doubled to 473 nm in the blue lasers A dichroic output coupler transmits a fraction of the doubled light out of the resonator while confining virtually all of the infrared beam inside the laser head The infrared pump power of the diode laser is mode matched in the laser crystal which together with the design of the resonator optics results in TEM output The lasers also operate in single longitudinal mode except for the two lower power green models which have multiple longitudinal mode output Refer to the tables of specifications at the end of this chapter Single longitudinal mode operation is achieved by inserting an etalon in the intracavity space to broaden the spacing of the longitudinal modes beyond the bandwidth of the laser gain so that only one mode at a time fits within the gain spectrum The higher power models of the green laser include an output telescope assembly that expands and collimates the beam before it exits the laser head Collimation i
36. lity M 1 1 Polarization 100 1 Beam diameter e points 0 10 0 01 mm Beam divergence full angle 7 4 mrad Beam Ellipticity 94 04 1 0 0 15 1 0 0 15 Stability Power Stability lt 2 Warm up Time lt 5 minutes Optical Noise Beam Pointing Stability Frequency Drift Boresight Tolerance Near field Far field lt x 0 596 rms lt 20 urad C lt 50 MHz C lt x0 5 mm x5 0 mrad 1 Specifications are subject to change without notice Vertical polarization Measured over an 8 hour period after warm up Measured over a 10 Hz to 100 MHz bandwidth Measured as far field x and y positions after a 5 minute warm up Excelsior Diode Pumped Visible CW Lasers Table 3 3 Environmental Specifications Operating Conditions Temperature range Laser Head Controller Humidity Vibration 10 C to 40 C 10 C to 45 C lt 80 non condensing for temperatures within range lt 1 5 m sec 0 15 G 15 200 Hz Non Operating Conditions Temperature range Humidity Vibration Shock 20 C to 60 C lt 90 non condensing for temperatures within range lt 20 m sec 2 G 15 200 Hz lt 300 m sec 30 G 11 msec Table 3 4 Electrical Mechanical Specifications Electrical Requirements Power Consumption Cooling Beam Height Weight all Laser Heads Controller Size I x h x w Laser Head 50 100 amp 150 mW Green 10 20 mW Green and 5 10 mW Blue
37. n and Operation 4 1 Installation aa exi ch ehe heiten serie REA 4 1 Power Supply Requirements 4 1 Thermal Management 2 ine ek REED REPRE RERUM te E Se ER n 4 1 Installing the Hardware 4 3 Controls and Connections 4 5 Operation ono ca Dr ER Moe Pa A O OE We Bat 4 7 Turning the Laser On and On 4 7 Using the Emission Indicator 4 8 Using the Diode Laser Alarm auuaaaaaaaaaaaaaaa aaa aaa na aaa nana nn 4 8 Changing the Laser Output Power 4 9 Interlock Jumper PIUG wasze narra eee OO ae RR RR E AS 4 9 Chapter 5 Troubleshooting and Service 000 cece eee eee eee 5 1 Maintenance 879 a Aas n A ee a arden earns 5 1 Service Training Programs 5 1 Troubleshooting i e A a SE MEER EGRE ERA Be 5 2 Replacement Parts ruere LER Parse er wee BE GR eg eine A Medes Gores 5 4 Customer Service cesso geben et nk Pai REGES bee ie eed deh e e Ed ve E E 5 5 Warranty cso gel a PE dE oO AO AE rer AE A 5 5 Returning the Instrument for Repair Rh 5 5 Service Centers au PT Rn Panne b en ne un rede 5 6 Notes Report Form for Problems and Solutions viii Table of Contents List of Figures Figure 1 1 The Excelsior Laser ee ale nee a ete meia Le aa er af 1 1 Figure 2 1 These standard safety warning labels are appropriate for use as entry warning signs EN 60825 1 ANSI Z136 1 Section 4 7 Lua aaaaaaaaa aaa aaa aaa aaa aaa A 2 2 Figure 2 2 Folded Metal Beam Target 2 2 Figure 2 3 Safety Devices
38. nistration Publication 8 1 7 U S Department of Labor 200 Constitution Avenue N W Room N3647 Washington DC 20210 Tel 202 693 1999 Internet http www osha gov A Guide for Control of Laser Hazards 4th Edition Publication 0165 American Conference of Governmental and Industrial Hygienists ACGIH 1330 Kemper Meadow Drive Cincinnati OH 45240 Tel 513 742 2020 Internet http www acgih org home htm Laser Institute of America 13501 Ingenuity Drive Suite 128 Orlando FL 32826 Tel 800 345 2737 Internet http www laserinstitute org Compliance Engineering Canon Communications LLC 11444 W Olympic Boulevard Los Angeles CA 90064 Tel 310 445 4200 International Electrotechnical Commission Journal of the European Communities EN 60825 1 Safety of Laser Products Part 1 Equipment classification requirements and user s guide Tel 41 22 919 0211 Fax 41 22 919 0300 Internet http www iec ch Cenelec 35 Rue de Stassartstraat B 1050 Brussels Belgium Tel 32 2 519 68 71 Internet http www cenelec org Document Center Inc 111 Industrial Road Suite 9 Belmont CA 94002 Tel 650 591 7600 Internet http www document center com Excelsior Diode Pumped Visible CW Lasers Equipment and Training 2 12 Laser Safety Guide Laser Institute of America 13501 Ingenuity Drive Suite 128 Orlando FL 32826 Tel 800 34LASER Internet http www laserinstitute org Laser Focu
39. or Diode Pumped Visible CW Lasers Notes 6 Report Form for Problems and Solutions We have provided this form to encourage you to tell us about any difficul ties you have experienced in using your Spectra Physics instrument or its manual problems that did not require a formal call or letter to our service department but that you feel should be remedied We are always interested in improving our products and manuals and we appreciate all suggestions Thank you From Name Company or Institution Department Address Instrument Model Number Serial Number Problem Suggested Solution s Mail To FAX to Spectra Physics Inc Attention Quality Manager Quality Manager 650 961 7101 1335 Terra Bella Avenue M S 15 50 Post Office Box 7013 Mountain View CA 94039 7013 U S A E mail sales spectra physics com www spectra physics com
40. or service in other countries refer to Service Centers on page 5 6 Order replacement parts directly from Spectra Physics For assistance of any kind contact your sales office or service center You will need your model and serial numbers available when you call To order optional items or other system components or for general sales assistance dial 1 800 SPL LASER in the United States or 1 650 961 2550 from anywhere else All parts and assemblies manufactured by Spectra Physics are uncondi tionally warranted to be free of defects in workmanship and materials for the period of time listed in the sales contract following delivery of the equipment to the F O B point Liability under this warranty is limited to repairing replacing or giving credit for the purchase price of any equipment that proves defective during the warranty period provided prior authorization for such return has been given by an authorized representative of Spectra Physics Spectra Physics will provide at its expense all parts and labor and one way return shipping of the defective part or instrument if required In warranty repaired or replaced equipment is warranted only for the remaining portion of the orig inal warranty period applicable to the repaired or replaced equipment This warranty also does not apply to equipment or components that upon inspection by Spectra Physics is found to be defective or unworkable due to abuse mishandling misuse altera
41. out 34 in above the baseplate mounting surface The heatsink surface for the laser head must be flat to 0 050 mm or better Excelsior Diode Pumped Visible CW Lasers Mount the Controller Follow standard practice to mount the controller on a suitable heatsink as described in the preceding section Use four M3 or 4 40 screws and washers to mount the controller using the mounting holes shown in Figure 4 4 5 039 1 319 lt gt 128 0 33 5 gt lt gt lt gt A yD QD n vi 3 913 99 4 Li E Zelle A SA a 3 150 80 0 LJ ER I ra ao Y Y 0 157 40 4 places le 5 433 ei 138 0 4 646 Dimensions given in HEBR lt gt m 118 0 G EXT NT G Se D Figure 4 4 Excelsior Controller Outline Drawing The laser head and controller can withstand a small amount of vibration and still perform to specification Refer to the specifications listed at the end of Chapter 3 for more information Installation and Operation Controls and Connections l Connect the one meter long laser head cable to the connector on the Excelsior laser head Refer toFigure 4 5 Cable TQ Laser Head Cable Connector Power Supply Connector Internal External Control Switch Figure 4 5 Excelsior Controller Connections 2 Connect the cable carrying the 5 Vdc po
42. ower supply voltage is between 4 5 V and 5 5 V and that the power supply is capable of supplying at least 30 W Check that all cables are securely connected Verify the controller INTERNAL EXTERNAL switch is set to INT If laser power is controlled externally set the INTERNAL EXTERNAL switch to EXT and provide a stable low noise 5 V signal to Pin 8 of the EXTER NAL CONTROL connector Symptom Low power Possible Causes Corrective Action Improper power supply volt age Loose cable connector Improper settings for the INTERNAL EXTERNAL switch Incorrect power measurement Laser is not warmed up Dirty output window Laser head temperature out side operating range Reflected laser light is desta bilizing the laser Diode pump laser has reached its end of life Verify the DC power supply voltage is between 4 5 V and 5 5 V and that the power supply is capable of supplying at least 30 W Verify all cables are securely connected Verify the Controller INTERNAL EXTERNAL switch is set to INT If laser power is controlled externally set the INTERNAL EXTERNAL switch to EXT and provide a stable low noise 5 V signal to Pin 8 of the EXTER NAL CONTROL connector Ensure that output power is measured as it leaves the laser head before the output beam enters any external optical elements Allow the laser to warm up for at least 5 minutes Clean the laser head output window Measure the temperature of the
43. perate as noted and you cannot correct the error please call your Spectra Physics service representative for assistance 0 39 uW for continuous wave operation where output is limited from 400 nm to 1400 nm Excelsior Diode Pumped Visible CW Lasers Radiation Safety Control Drawings Refer to the warning labels on page 2 10 Laser Head output beam Controller w l el EXT External Control Cable Connector Figure 2 5 Excelsior Radiation Control Drawings 2 6 Warning Labels VISIBLE AND OR NVISIBLE LASER RADIATION IS EMITTED FROM THIS APERTURE 0420 790 0 AVOID EXPOSURE Aperture Label Laser Head 1 LASER RADIATION AVOID EXPOSURE TO BEAM CLASS 3B LASER PRODUCT MAXIMUM CW OUTPUT POWER lt 500mW WAVELENGTH 532 nm 473 nm OEM Danger Label 4 C CE Certification Label 6 WEEE Label 7 Figure 2 6 Warning Labels CE Aperture Label 2 Laser Safety Warranty Seal 3 S Spectra Physics 1335 Terra Bella Avenue Mountain View CA 94043 MANUFACTURED IN JAPAN MFG P N MONTH YEAR S N 150 0110 OEM Serial Number Label 5 Spectra Physics Lasers POST OFFICE BOX 7013 MT VIEW CA 94039 7013 THIS PRODUCT IS MANUFACTURED UNDER ONE OR MORE OF THE FOLLOWING PATENTS U S PATENT NUMBERS 4 756 003 4 872 177 5 870 415 Patent Label 8 Excelsior Diode Pumped Visible CW Lasers Label Translations For safety th
44. placement Parts The following is a list of parts that may be purchased to replace broken worn out or misplaced components Table 5 1 Replacement Parts Description Part Number Excelsior green 10 mW laser head Excelsior green 10 mW laser head collimated output Excelsior green 20 mW laser head Excelsior green 20 mW laser head collimated output Excelsior green 50 mW laser head Excelsior green 100 mW laser head Excelsior green 100 mW laser head Excelsior blue 5 mW laser head Excelsior blue 10 mW laser head Excelsior Controller Excelsior 532 10 Excelsior 532 10 C Excelsior 532 20 Excelsior 532 20 C Excelsior 532 50 Excelsior 532 100 Excelsior 532 150 Excelsior 473 5 Excelsior 473 10 Excelsior PS 5 4 Customer Service Warranty Troubleshooting and Service At Spectra Physics we take great pride in the reliability of our products Considerable emphasis has been placed on controlled manufacturing meth ods and quality control throughout the manufacturing process Neverthe less even the finest precision instruments will need occasional service Our instruments have excellent service records compared to competitive prod ucts and we strive to provide excellent service to our customers in two ways by providing the best equipment for the price and by servicing your instruments as quickly as possible When calling for service inside the United States dial our toll free number 1 800 456 2552 To phone f
45. product serial label for wavelength nm and laser power Note a This product is an OEM laser system As such it does not conform to the safety specifications and performance standards required of a Class IV laser as defined by the Center for Devices and Radiological Health CDRH 21 CFR 1040 Precautions For The Safe Operation Of Class Illb High Power Lasers Wear protective eyewear at all times selection depends on the wave length and intensity of the radiation the conditions of use and the visual function required Protective eyewear is available from suppliers listed in the Laser Focus World Lasers and Optronics and Photonics Spectra buyer s guides Consult the ANSI and ACGIH standards listed at the end of this section for guidance Maintain a high ambient light level in the laser operation area so the eye s pupil remains constricted reducing the possibility of damage Avoid looking at the output beam diffuse reflections are hazardous Establish a controlled access area for laser operation Limit access to those trained in the principles of laser safety Enclose beam paths wherever possible Post prominent warning signs near the laser operating area Figure 2 1 Install the laser so that the beam is either above or below eye level Set up shields to prevent any unnecessary specular reflections or beams from escaping the laser operation area Set up a beam dump to capture the laser beam and prevent accidental expos
46. r can be used to control an external laser emission indicator See Chapter 4 for an example of a circuit used for this purpose Safety Interlock Pin 2 of the EXTERNAL CONTROL connector can be used as a safety inter lock The function of Pin 2 is to provide an on off signal to the laser See Chapter 4 for an example of a circuit used to turn the laser emission on or off By connecting a safety switch in series with such a circuit the laser can be made to turn off when the safety switch is opened The switch can be attached to a laboratory door or similar critical access point to limit access to the laser system or master system Cover Safety Interlocks The Excelsior lasers are OEM systems that are designed to be integrated into a master system that itself complies with regulatory requirements As such the individual components of the laser system the laser head and controller do not have cover safety interlocks The laser head and con troller covers are not to be opened by the user When the diode pump laser in the Excelsior laser requires replacement the entire laser head must be replaced as a unit Before starting the replacement procedure the controller must be disconnected from the AC electrical service The Excelsior laser is not intended to be operated with the cover removed Maximum Emission Levels The following are the maximum emission levels possible for the different Excelsior laser systems Use this information for selec
47. rnal optical elements does not reflect bilizing the laser back through the window of the laser head Improper ground Check the grounding of the laser head and the controller Vibration outside of operating Ensure that any vibration experienced by the laser head is within operating limits limits Power supply ripple Verify the power supply ripple is below 150 mV peak to peak External noise source Check that there are no strong electromagnetic noise sources near the sys tem If the output power is controlled externally verify the voltage signal applied to Pin 8 of the EXTERNAL CONTROL connector is low noise Symptom Bad transverse mode Possible Causes Corrective Action Improper power supply volt Verify the DC power supply voltage is between 4 5 V and 5 5 V and that the age power supply is capable of supplying at least 30 W Improper settings for the Verify the controller INTERNAL EXTERNAL switch is set to INT INTERNAL EXTERNAL If laser power is controlled externally set the INTERNAL EXTERNAL switch switch to EXT and provide a stable low noise 5 V signal to Pin 8 of the EXTER NAL CONTROL connector Laser is not warmed up Allow the laser to warm up for at least 5 minutes Dirty output window Clean the laser head output window Laser head temperature out Measure the temperature of the baseplate If it is below 10 C or exceeds side operating range 50 C verify the ambient temperature is within the allowable operating ran
48. s World Buyer s Guide Laser Focus World Pennwell Publishing 98 Spit Rock Road Nashua NH 03062 Tel 603 891 0123 Internet http Ifw pennnet com home cfm Photonics Spectra Buyer s Guide Photonics Spectra Laurin Publications Berkshire Common PO Box 4949 Pittsfield MA 01202 4949 Tel 413 499 0514 Internet http www photonics com Chapter 3 System Description A Brief Review of Laser Theory Emission and Absorption of Light Laser is an acronym derived from Light Amplification by Stimulated Emis sion of Radiation Because the laser is an oscillating amplifier of light and because its output comprises photons that are identical in phase and direc tion it is unique among light sources Its output beam is singularly direc tional monochromatic and coherent Radiant emission and absorption take place within the arrangement of the electrons in atoms or molecules Each electron occupies a distinct orbital that represents the probability of finding the electron at a given position rel ative to the nucleus The energy of an electron is determined by the orbital that it occupies and the over all energy of an atom its energy level depends on the distribution of its electrons throughout the available orbit als Each atom has an array of energy levels the level with the lowest possible energy is called the ground state and higher energy levels are called excited states If an atom is in its ground state it will
49. s offered as an option for the lower power green lasers as well which are otherwise uncollimated The output of the blue lasers is uncollimated Again refer to the tables of specifications for exact details All models of the Excelsior include an internal detector to measure output power The detector is part of a servo loop that maintains constant laser output power over the lifetime of the device by adjusting the current of the diode pump System Description Mechanical and Thermal Design The laser resonator is machined from a solid piece of brass for exceptional thermal and mechanical stability The waste heat produced by the diode pump laser typically less than 2 W is removed from the laser head by thermal conduction through the baseplate The laser crystal is set to a stable operating temperature of about 45 C by a thermal electric cooler TEC that is located in the head beneath the laser cavity The mechanical design of the miniature laser heads allows for mounting the lasers using precision alignment pins Together with the excellent sta bility and boresight specifications of the Excelsior this facilitates both the design of the master optical train as well as the replacement of the laser head when the diode pump laser eventually reaches its end of life condi tion The Excelsior Controller Note g Danger Laser Radiation Power for the laser as well as monitoring and control are provided to the laser head through the
50. small separate controller unit The same controller is used on all models of the Excelsior without mod ification The Excelsior system produces output signals proportional to the laser power and the diode pump current as well as an alarm for the diode life time and a status signal that can be used to control a laser emission indica tor These features are all available through the Excelsior controller An interlock jumper plug Figure 3 6 is provided with the system to allow operation without an external control cable during test and installation Note that when power is supplied to the laser the laser will come on immediately when either the ON signal is present or the jumper plug is inserted into the EXTERNAL CONTROL connector of the controller Figure 3 6 Interlock Jumper Plug Power Supply Requirements The Excelsior requires up to 6 Amps of regulated 5 Vdc power to drive the diode pump laser See the installation section in Chapter 4 for more information 3 9 Excelsior Diode Pumped Visible CW Lasers Specifications Table 3 1 Excelsior Green Laser Output Specifications 10 and 20 mW Excelsior 50 100 and 150 mW Excelsior Power Excelsior 532 10 10 0 2 mW Excelsior 532 20 20 0 5 mW Excelsior 532 50 50 0 5 mW Excelsior 532 100 100 21 0 mW Excelsior 532 150 150 1 0 mW General Characteristics Wavelength 532 nm 532 3 0 3 nm Longitudinal Mode multi single Sp
51. stay there until it is excited by external forces Movement of an electron from one energy level to another a transition happens when the atom either absorbs or emits energy Transitions in both directions can occur as a result of interaction with a photon of light Con sider a transition from a lower level whose energy content is E to a higher one with energy E It will only occur if the energy of the incident photon matches the energy difference between levels i e hv 2 E E 1 where h is Planck s constant and v is the frequency of the photon Likewise when an atom excited to E decays to E it loses energy equal to E E The atom may decay spontaneously emitting a photon with energy hv and frequency ETE 2 SE Light will be used to describe the portion of the electromagnetic spectrum from the infrared to the ultraviolet Excelsior Diode Pumped Visible CW Lasers Population Inversion 3 2 Spontaneous decay can also occur without emission of a photon An atom excited to E can also be stimulated to decay to E by absorbing a photon of frequency v then emitting a pair of photons that are identical to the inci dent one in phase frequency and direction This is known as stimulated emission By contrast spontaneous emission produces photons that have no directional or phase relationship with one another A laser is designed to take advantage of both stimulated and spontaneous emission and absorption
52. that is transmitted through the output coupler as the laser beam There is one standing wave pattern or cavity mode that has the simplest possible form termed TEM TEM operation results from choosing the mirror curvatures and the shape and pumping geometry of the laser mate rial so that gain is confined along the central axis of the material this is fur ther discussed in the section Diode Pumped Laser Design below The TEM mode appears brightest in the center and attenuates smoothly toward the edges of the beam The spectral content of the light in this mode arises from the standing waves formed along the axis of the cavity with frequencies determined by the separation between the resonator mirrors The difference in frequency between any two of these longitudinal modes is given by c 3 ded 3 where c is the speed of light n is the refractive index and is the distance between the cavity mirrors The number of such longitudinal modes in the laser output is determined by the number of such modes that fall under the bandwidth of the gain material as shown in Figure 3 2 E 7 2L pa Longitudinal Modes Gain E Envelope FWHM Point 5 6 10 GHz LLL Frequency v gt Figure 3 2 Frequency Distribution of Longitudinal Modes Excelsior Diode Pumped Visible CW Lasers Single Longitudinal Mode Operation Some laser applications benefit from a beam with only a single longitudinal mode From equation 3
53. ting appropriate laser safety eyewear and implementing appropriate safety procedures These values do not imply actual system specifications Table 2 1 Maximum Emission Levels Emission Wavelength Maximum CW Output Power Diode Laser Emission 808 nm 2W Laser Head Emission 1064 nm 1 5W Laser Head Emission 532 nm 0 5 W Laser Head Emission 473 nm 0 1 W Laser Safety Requirements for Safely Operating the Excelsior Laser System with a User provided Control Device When the Excelsior laser system is controlled by a device provided by the user or software written by the user the following must be provided Akey switch that limits access to the laser and prevents it from being turned on It can be a real key lock a removable computer disk a pass word that limits access to computer control software or a similar key implementation The laser must only operate when the key is present and in the on position e An emission indicator that indicates laser energy is present or can be accessed It can be a power on lamp a computer display that flashes a statement to this effect or an indicator on the control equipment for this purpose It need not be marked as an emission indicator so long as its function is obvious Its presence is required on any control panel that affects laser output Schedule of Maintenance in Accordance with Center for Devices and Radiological Health CDRH Regulations This las
54. tion negligence improper installa tion unauthorized modification damage in transit or other causes beyond the control of Spectra Physics This warranty is in lieu of all other warranties expressed or implied and does not cover incidental or consequential loss Returning the Instrument for Repair Contact your nearest Spectra Physics field sales office service center or local distributor for shipping instructions You are responsible for one way shipment of the defective part to Spectra Physics Instruments can be returned only in Spectra Physics containers We encourage you to use the original packing boxes to secure instruments during shipment If shipping boxes have been lost or destroyed we recommend ordering new ones Excelsior Diode Pumped Visible CW Lasers Service Centers 5 6 Belgium Telephone 32 0800 1 12 57 France Telephone 33 0810 00 76 15 Germany and Export Countries Spectra Physics GmbH Guerickeweg 7 D 64291 Darmstadt Telephone 49 06151 708 0 Fax 49 06151 79102 Japan East Spectra Physics KK East Regional Office Daiwa Nakameguro Building 4 6 1 Nakameguro Meguro ku Tokyo 153 0061 Telephone 81 3 3794 5511 Fax 81 3 3794 5510 Japan West Spectra Physics KK West Regional Office Nishi honmachi Solar Building 3 1 43 Nishi honmachi Nishi ku Osaka 550 0005 Telephone 81 6 4390 6770 Fax 81 6 4390 2760 The Netherlands Telephone 31 0900 5 55 56 78 United Kin
55. to produce the 1064 nm wavelength for doubling to 532 nm Vanadate is a popular solid state laser material for small to medium power solid state lasers due to its low threshold for lasing along with its large cross section for stimu lated emission Neodymium can be made to lase at other wavelengths at 946 nm in partic ular This 946 nm transition has a lower gain and a higher threshold than the 1064 nm transition When lasing at this wavelength is desired it can be achieved by choosing the proper wavelength selective coatings for the res onator mirrors Such coatings transmit a high percentage of any 1064 nm light that might be present thus decreasing the rate of stimulated emission for this wavelength and allowing the 946 nm transition to lase The 946 nm transition is referred to as quasi three level because the lower laser level lies so close to the SE 9 ground state Despite this small difference in energy the lower laser lev l still empties quickly enough to allow CW operation for this wavelength However the small difference in energy from the ground state does mean that the material will self absorb at the lasing wavelength Self absorption is a parasitic effect where the laser light is absorbed by the laser crystal itself The lower laser level for the quasi three level transition in vanadate is significantly populated by electrons thermally excited from the ground state resulting in absorption of the 946 nm light as the
56. ure Figure 2 2 2 1 Excelsior Diode Pumped Visible CW Lasers VISIBLE AND OR INVISIBLE LASER RADIATION A CN ae AVOID EYE OR SKIN EXPOSURE TO AVOID EYE OR SKIN EXPOSURE TO DIRECT DIRECT OR SCATTERED RADIATION SCATTERED RADIATION CLASS 3B LASER PRODUCT 473 NM OR 532 NM WAVELENGTH MAXIMUM OUTPUT 500 mw 473 NM or 532 NM WAVELENGTH MAXIMUM OUTPUT 500 mW CLASS Illb LASER PRODUCT Figure 2 1 These standard safety warning labels are appropriate for use as entry warning signs EN 60825 1 ANSI Z136 1 Section 4 7 Figure 2 2 Folded Metal Beam Target Danger Use of controls or adjustments or performing the procedures described LE o in this manual in a manner other than specified may result in hazardous radiation exposure manner that does not comply with recommended procedures may be dangerous At all times during installation maintenance or service of your laser avoid unnecessary exposure to laser or collateral radiation that exceeds the accessible emission limits listed in Performance Standards for Laser Products United States Code of Federal Regulations 21 CFR 1040 10 d Danger W Operating this laser without due regard for these precautions or in a Follow the instructions contained in this manual to ensure proper installa tion and safe operation of your laser Any electronic product radiation except laser radiation emitted by a laser product as a result of or necessary for the
57. ve Keep the shipping container If you file adamage claim you may need it to demonstrate that the damage occurred as a result of shipping If you need to return the system for service at a later date the specially designed con tainer assures adequate protection System Components Accessories Two components comprise an Excelsior laser system e Excelsior laser head one of seven models e Excelsior controller The controller weighs about 0 3 kg 0 7 Ib The laser head weighs about 0 25 kg 0 6 Ib Both can be handled easily by one person Verify that both components are present The laser head and controller are shipped in one container Included with the laser is this manual a packing slip listing all the parts shipped and an accessory kit The following accessories are shipped stan dard with the system e LASER HEAD cable 1 m e INTERLOCK jumper plug XV Chapter 1 Introduction Figure 1 1 The Excelsior Laser Spectra Physics Excelsior lasers produce a green or blue continuous laser beam from an exceptionally compact package These small rugged diode pumped solid state lasers are especially well suited for applications requiring a low noise high quality CW visible beam Excelsior lasers are intended for OEM integration into master systems There are seven lasers in the Excelsior family five green lasers with an output between 10 mW and 150 mW at 532 nm and two blue lasers with outputs of 5 mW or 1
58. wer to the 9 pin POWER SUPPLY D sub connector on the controller The high current level should be shared by the connector pins Verify the cable is securely fastened to the controller 5 VDC in Pins 1 2 6 and 7 Ground return Pins 4 5 8 and 9 3 Next connect a cable with a 15 pin D sub connector to the EXTERNAL CONTROL connector on the controller The sequence for the pin num bering is shown in Figure 4 6 looking at the controller connector Pin numbers proceed from right to left 4 5 Excelsior Diode Pumped Visible CW Lasers 5 1 15 11 Figure 4 6 External Control Connector Pin Numbering The function of each of these pins is listed below Table 4 1 External Control Connector Pin Functions Pin Type Description Function 1 Output Laser OK This pin is internally shorted to ground when the laser is in stable operation i e laser output power is at the speci fied level and the laser head temperature is within the proper operating range Pin 1 can be used as a switch for a laser emission indica tor as shown in Figure 4 8 2 Input Laser ON OFF When this pin is shorted to ground the laser will turn on immediately if 5 Vdc power is available to the laser head through the controller Refer to Turning the Laser On and Off on page 4 7 for instructions on using this input 3 N A Reserved Must be open 4 Output Current Monitor Pin 4 provides an output signal proportional to the current of the
59. y in phase over a sufficient length in the nonlinear material to allow the conversion to take place In most nonlinear materials however the indices of refraction at the two wavelengths will be significantly different causing the two waves to become rapidly out of phase unless special techniques are employed One such technique takes advantage of the birefringence of nonlinear crystals The indexes of refraction of the two light waves can be made to match exactly if the direction of propagation and the polarization orientation of the beams within the crystal are carefully controlled This technique is referred to as critical phase matching LBO and KTP are nonlinear crys tals that lend themselves well to this technique The high nonlinear coefficient of KTP has made it historically a very popu lar material for conversion of lower power 1064 nm infrared lasers to green wavelengths KTP can be fabricated in a specialized structure that keeps the infrared and green beams in an approximate phase matched condition over a longer distance than in a typical bulk crystal Although LBO has a comparatively smaller nonlinear coefficient it pro duces no spatial walk off of the fundamental and second harmonic beams This favors a long interaction length for higher gain Consequently LBO has subtle advantages that provide superior conversion efficiency of CW infrared laser light to blue wavelengths The second harmonic power P5 produced by
60. y the laser is important to maintaining its specified output Refer to Thermal Management below for details Power Supply Requirements Thermal Management The laser is powered by a low noise 150 mV ripple peak to peak 5 Vdc power source connected to the controller The source must be capable of providing 30 Watts 6 A maximum current Laser Head The laser head must be mounted on a heatsink capable of maintaining its baseplate temperature below 50 C and greater than 10 C The diode pump laser in the laser head will produce several Watts of waste heat that must be removed through the baseplate by the heatsink see Figure 4 1 4 1 Excelsior Diode Pumped Visible CW Lasers 4 2 Cooler ambient temperatures for the environment of the laser will make the job of dissipating waste heat through the baseplate easier see Figure 4 2 The heatsink surface must be flat to 0 050 mm or better 12 Heat Load W O 0 _ III EEE ER ER WA OOOO 0 10 20 30 40 50 60 70 Laser Head Baseplate Temperature C Figure 4 1 Heat Dissipation of the Laser Head 0 L l l L 0 10 20 30 40 50 60 Maximum Permissible Heat Sink Thermal Impedance C W Ambient Temperature C Figure 4 2 Laser Head Heatsink Thermal Impedance for 50 C Base plate Temperature Controller The Excelsior controller transfers a significant current load in a relatively small package to the
61. ye damage Turning the Laser On and Off Starting and stopping the laser is straightforward once 5 Vdc power is connected to the laser head use a switching circuit similar to that shown in Figure 4 7 below to turn the laser on or off The laser will be ready to per form according to specifications after a 5 minute warm up Danger Note that the Excelsior emits laser radiation immediately after Pin 2 of Laser Radiation the EXTERNAL CONTROL connector receives the ON signal Take care to protect against unexpected exposure A simple circuit to turn the laser on and off is shown below If a suitable drive current is supplied from a 5 Vdc source to Pin 2 of the EXTERNAL CONTROL connector the diode pump laser will turn on and the Excelsior will emit laser light Laser ON OFF 5 V I I I MN I PIN 2 Dn I Input I 09 GND O o GND 772 I Controller I Extern al Circuit Figure 4 7 Laser On Off Control Example Note that the ground pins of the EXTERNAL CONTROL connector are Pins 6 and 7 and Pins 10 and 11 4 7 Excelsior Diode Pumped Visible CW Lasers Using the Emission Indicator An example of a simple circuit used to turn an emission indicator on and off is shown in Figure 4 8 below When the laser output is at its specified level and the laser head tempera ture is within operating range the internal transistor connected to Pin 1 in the circuit shown in Figure 4 8 will turn on The LED shown in the

Excelsior - Spectra

Contents

Download Pdf Manuals

Related Search

Related Contents