User Manual - CEO Knowledge Center
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1. 5 Verify that there are no objects in the laser beam path except for the negative lens and power meter WARNING Wear proper laser safety eyewear to protect your eyes 6 Once all the parameters are set correctly and temperatures of TEC Controller and chiller are stabilized set the current at 10 A and begin current flow to the diodes Open the laser shutter Gradually increase the current until the laser is firing at very low power Move the negative lens and power meter so that the beam is going through the center of the lens and hitting the center of the power meter 7 Gradually increase the current set point to the operating current specified in the test report Do not touch any part of the laser and wait for the laser to stabilize for 1 hour usually the laser takes about 20 minutes to reach 95 percent of the maximum power Then check if the power is close to the result on the test report Usually the laser needs optimization for the first installation due to the slight differences of environments chiller settings and vibration of the transportation If so please follow the laser performances optimization procedures Chapter 5 Maintenance Daily Operation Output energy and repetition rate of the Iklwa laser system are adjustable over a wide range However operating protocols must be observed to assure operation without risking internal damage to optical components Table 1 1 summarizes laser performance Northrop Grumman C2. Power 3 o oa 26 26 5 ZA 27 5 28 28 5 29 29 5 30 30 5 Temperature Deg C Figure 5 2 Example of Power Dependence and Pulse to Pulse Instability of the laser to SHG Crystal Temperature 4 Peak the laser power by increasing the current Figure 5 3 illustrates an example of the dependence of the output power and pulse to pulse instability of the Iklwa laser to operating current Notice that the laser power increases as the operating current is increased The laser reached peak power around 23 A Search for the peak power by changing the current 0 1 A increments around the operating current Once the peak power is found lower the current to reach 99 5 percent of the peak power This is the proper operating current In this example the operating current would be 22 9 A The slight difference between the actual operating current and the test report value may be due to the performance difference of the chillers An increase in the operating current can compensate for the aging of the Iklwa s laser diodes Northrop Grumman Corporation 37 Ikiwa Laser User Manual Chapter 5 Maintenance Laser Performance Versus Current tee H Ower nstability o nm OO a Power WU Instability Yorms No On St CH 20 20 5 21 245 22 22 5 23 235 24 Pumping Current A Figure 5 3 Example of Laser Performance Dependence on the Operating Current 5 Peak up the laser with adjustment of
3. 1 Wait for the laser reach thermal stabilization Both the laser bench temperature and environmental temperature significantly impact the laser power Wait for the laser to be thermally stabilized before attempting any adjustment 2 Check the settings of the diode power supply and chiller Check the performance with all items set to the values on the laser test report The water flow rate and coolant temperature have a significant impact on the laser performance Make sure that the flow rate is above 1 4 gpm and the temperature of the chiller matches results from the original test report 3 Peak up the laser power by tuning the temperature of the TEC controller The phase matching of the second harmonic generation SHG crystal is crucial for the Iklwa laser This is achieved by setting the proper temperature on the SHG crystal which is controlled by the TEC controller Figure 5 2 illustrates an example of the dependences of power and pulse to pulse instability of the laser to the SHG crystal temperature As shown in the example the mid point of the temperature band is around 28 5 C The laser may have peak power at 29 3 C in this example but a small temperature change on the SHG could result in a power fluctuation Northrop Grumman Corporation 36 Ikiwa Laser User Manual Chapter 5 Maintenance Laser Performance Dependence on Temperature of SHG 20 0 E 5 sy gt 2 Teen E
4. Cutting Edge Optronics Inc 20 Point West Boulevard Saint Charles MO 63301 USA Phone 636 916 4900 Fax 636 916 4994 Email ngceoservice ngc com Northrop Grumman Corporation 49 Ikiwa Laser User Manual Appendix B System International Units The following System International SI units abbreviations and prefixes are used throughout Northrop Grumman Cutting Edge Optronics user manuals Quantity Unit Symbol Abbrv Prefixes mass gram g tera 107 T length meter m giga 109 G time second s mega 109 M frequency Hertz Hz kilo 10 k force Newton N deci 107 d energy Joule J centi 1 07 c power Watt W milli 10 m electric current Ampere A micro 1 0 u electric charge Coulomb C nano 10 n electric potential Volt V pico 1072 p resistance ohm Q femto 1079 f inductance Henry H atto 1078 a magnetic flux Weber Wb magnetic flux Tesla T density luminous intensity candela cd temperature Kelvin K Northrop Grumman Corporation 50 Ikiwa Laser User Manual Appendix C Acronyms Acronym ACGIH ANSI AO AR ATP CDRH CW FPS HeNe HM HR IEC LBO Ne Nd YAG nm OSHA PRF Northrop Grumman Corporation Description American Conference of Government Industrial Hygienists American National Standards Institute Acousto optic Anti Reflective Acceptance Test Procedure Center for Devices and Radiologica
5. Hor your local distributor for shipping instructions Please package the products as directed for a return for repair ROC ROHS Declaration In accordance with the Clause 6 2 of Marking for Control of Pollution Caused by Electronic Information Products SJ T11364 2006 for Measures for the Administration on Pollution Control of Electronic Information Products No 39 Order of the Ministry of Information Industry of the Peoples Republic of China NG CEO includes the following translation about our laser system PEARCE CFRE STEDE ORAR kui Northrop Grumman Cutting Edge Optronics Pg be ab 20 Pointe West Blvd St Charles MO 63301 USA TRE HH Mirus Series Laser Systems Models Mi xxx xxxx xxxx and AMI xxx xxxxocexx SERIES RASER WW im x EI AE SURE ST R MPA S AT BR Pb Hg Cd CrVI PBB PBDE SR AK oO SS Bhs ERA S ERM E EGI FERF BAM URE FRAG HEM IER HE FE EN KI KT E 8 LS S ETT HERR EEN SZ FEE HMR EE Aa inn Rw Lo 0 SERRURIER X BREDDEN EAMES EANA GANDY SMM SI T 11369 2006 MERRER o O x O zt x lt O O lt jO O0 0 0 j0 O 0 o o olo Ox j NA iz i Northrop Grumman Corporation iv Iklwa Laser User Manual Conventions The following conventions appear in this manual This icon denotes a caution or a warning which advise you of precautions to take to avoid injury data loss or a syst
6. causing eye or skin damage from direct exposure or specular reflection of the beam Always replace the screws in the alignment holes WARNING Additional adjustment holes in the top cover of the laser housing provide access to the HR cavity mirror and HM cavity mirror The access holes should be always covered unless an alignment is being performed Dust particles can cause damage to the mirrors and crystals inside the laser All the holes on the laser enclosure should be sealed all times to prevent moisture penetration Moisture in the enclosure can degrade the lifetime of SHG crystal as well as the coatings on all optical components Access Holes for Clockwise Moves Beam to Right HR Adjustment Counter Clockwise Moves Beam to Left Clockwise Moves Beam Down Counter Clockwise Moves Beam Up Clockwise Moves Beam to Right Access Holes for Counter Clockwise Moves Beam to Left HR Adjustment Clockwise Moves Beam Down Counter Clockwise Moves Beam Up Figure 3 3 Ikiwa Top View Northrop Grumman Corporation 12 Ikiwa Laser User Manual Chapter 3 System Details Ikiwa Wiring Interface MS3476L16 265 LASER SIGNAL CONNECTOR 380AS001M1610M3 ELECTRONIC INTERFACE LASER INTERFACE Figure 3 4 Ikiwa J 1 Connector Interface Northrop Grumman Corporation 13 Ikiwa Laser User Manual Chapter 3 System Details Table 3 1 J 1 Connections Pin Signal Descriptio
7. control system must be capable of maintaining the temperature set point to 0 1 C with a flow rate of 1 5 gpm 5 7 Ipm An input pressure of approximately 49 psi is required at the laser housing Chiller pressure may be several psi higher if additional filtering flow metering fittings and long runs of coolant tubing are used Coolant used in the system must be compatible with the materials used in the internal coolant lines of the laser Tap or de ionized water must be avoided because of corrosion and mineral deposits NG CEO can supply an approved coolant for this application Northrop Grumman Corporation 5 Ikiwa Laser User Manual Chapter 2 Laser Safety Please read this chapter carefully before installing or operating your laser An NG CEO trained service engineer should perform all service and repair operations If you plan to service your laser please follow the procedures in Chapter 5 Maintenance Sections included in this chapter include Safety Overview Precautions for Safe Operation Caution and Warning Statements CDRH Compliance Northrop Grumman Corporation 6 Ikiwa Laser User Manual Chapter 2 Laser Safety Safety Overview Safe laser operation should be reviewed prior to any new installation of the Ikiwa laser CAUTION The Ikiwa laser is a Class IV high power laser whose beam is by definition a safety hazard Avoid eye or skin exposure to direct or scattered laser radiation Avoid direct v
8. hazards To minimize the risk of injury or expensive repairs carefully follow these instructions Do not attempt to operate the laser system before carefully reading this complete operation manual If you have any guestions on the product that have not been discussed sufficiently in this manual contact the manufacturer for complete instructions Failure to heed this warning may result in the destruction or serious damage to the device and will void the product warranty The trouble shooting section is intended to help guide you to the source of problems Do not attempt repairs while the unit is under warranty instead report all problems to NG CEO for warranty repair Use the form in Appendix A Customer Service to describe issues with the laser We also suggest that you record information about the laser such as power settings time and date Northrop Grumman Corporation vii Ikiwa Laser User Manual About This M anual This manual describes the installation operation and service of the Iklwa Laser System The manual consists of the following chapters Northrop Grumman Corporation Chapter 1 Introduction provides a theory of laser operation and a description of the Ikiwa laser Chapter 2 Laser Safety describes proper safety procedures you should understand before operating the Ikiwa laser Chapter 3 System Details provides information about components of a laser system and proper environmental conditions for ope
9. of the giant pulse is dependent on the non lasing duration as well as the operating current Figure 4 9 First Giant Pulse with FPS Disabled CAUTION The FPS has to be enabled and parameters for FPS have to be set properly Failure to suppress the first giant pulse may cause the internal optical damage as well as damage to the work piece For each type of laser processing a particular operating current and pulse repetition rate are needed The giant pulse can be suppressed by enabling FPS and setting the proper FPS parameters To set the FPS properly use a photodiode detect with response time ns and an oscilloscope Northrop Grumman Corporation 31 Ikiwa Laser User Manual Chapter 5 Maintenance The chapter contains information in these sections Northrop Grumman Corporation Prepare for shipment Purge housing Replace desiccant cartridge Maintain chiller Check hold off Extend lifetime of laser diodes Optimize laser performance 32 Ikiwa Laser User Manual Chapter 5 Maintenance Prepare for Shipment It is anticipated that in OEM applications the Ikiwa laser will be installed in another system that will be shipped internationally The Ikiwa optical assembly must be properly prepared for shipment if internal damage is to be avoided due to possible freezing of trapped water in the coolant lines This procedure follows 1 Ready a dry gas source in preparation for draining the system Oil free dry f
10. the cavity mirrors WARNING Making mirror adjustments can be non reversible Do this step only when all the steps above have been completed and the laser does not meet the specifications with the correct settings Northrop Grumman Corporation Locate the access holes for high reflection HR and harmonic mirrors HM Notice the positions of HR and HM mirrors with respect to the direction of the laser output in Figure 5 4 Remove screws from access holes only in a dust free environment Use a 1 8 inch ball driver to make adjustments A fine adjustment is a 1 degree or less rotation A small adjustment is about a 2 degree rotation A coarse adjustment is 15 degrees to 20 degrees rotation If coarse adjustments are needed to obtain performance reduce operating current by 2 A Return to normal operating current when making small and fine adjustments The screws for the adjustments of the vertical tilt angle and the horizontal tilt angle are illustrated in Figure 5 4 38 Ikiwa Laser User Manual Chapter 5 Maintenance ACCESS HOLES FOR HR ADJUSTMENT Laser Out LOCKWISE MOVES BEAM TO RIGHT COUNTER CLOCKWISE MOVES BEAM TO LEFT LOCKWISE MOVES BEAM DOWN COUNTERCLOCKWISE MOVES BEAM UP CLOCKWISE MOVES BEAM DOWN COUNTERCLOCKWISE MOVES BEAM UP LOCKWISE MOVES BEAM TO RIGHT c COUNTER CLOCKWISE MOVES BEAM TO LEFT Northrop Grumman Corporation ACCESS HOLES FOR HM ADJUSTMENT Figure 5 4 Accessible Holes fo
11. 0 50 60 70 80 90 100 10 43 9 20 2 11 9 6 8 3 0 0 1 2 6 4 8 6 7 8 4 10 0 12 42 6 18 7 10 3 5 0 1 2 1 9 4 5 6 7 8 7 10 4 12 0 34 29 5 1 9 7 8 13 9 22 1 25 1 27 7 30 0 32 1 16 40 2 15 6 7 0 1 6 2 4 5 6 8 2 10 5 12 5 14 4 16 0 18 39 0 14 1 5 3 0 2 4 2 7 4 10 1 12 4 14 5 16 3 18 0 o BEES 6 HI 5 22 36 6 11 0 2 0 3 6 7 8 11 1 13 9 16 3 18 4 20 3 22 0 g 24 35 4 9 5 0 4 5 3 9 6 12 9 15 7 18 2 20 3 22 3 24 0 E o e i ae 7 66 lt 28 33 0 6 5 2 9 8 8 13 1 16 6 19 5 22 0 24 2 26 2 28 0 30 31 8 4 9 4 6 10 5 14 9 18 4 21 4 23 9 26 2 28 2 30 0 34 0 36 28 3 40 26 0 0 4 2 6 9 5 12 7 15 7 19 4 20 2 23 8 23 9 27 6 27 0 30 7 29 6 33 5 32 0 35 9 34 1 38 0 36 0 40 0 If required to operate a laser in conditions near to the condensation temperature take precautions to keep the laser dry The laser should be operated inside an area that is purged with nitrogen N2 or encased in a sealed enclosure with a desiccant Northrop Grumman Corporation Ikiwa Laser User Manual Chapter 4 Installation and Operation To ensure safe operation of the Iklwa laser system refer to TEC Controller User Manual the Chiller User Manual and the diode drive power supply User M
12. 3 5 25 28 29 30 44 45 47 Q Switch 34 RoHS iv sales support ii service support ii SHG 12 18 27 32 35 36 38 39 44 51 shock hazard vi signal cable 26 symbols v TEC controller 3 28 29 35 44 47 technical support ii WEEE iv 53 Ikiwa Laser User Manual
13. Gradually increase the current to the full operation current level Observe the beam output on the power meter Hold off condition is met when no green light is visible If green is observed the laser does not hold off and may need internal repair Reduce the current to 10 A Return the Q Switch controller to the normal operating settings Gradually increase the current to the operation current 35 Ikiwa Laser User Manual Chapter 5 Maintenance Extend Lifetime of Laser Diodes The specification for laser system optical output is provided in the final test report delivered with the system During its early lifetime the laser diodes will deliver this specified power at or below the preset current limit As the diodes age an increase in current may be required to maintain power and beam quality so the diodes can continue to be used Once the maximum current of 30 A is reached consider replacing diodes or upgrade the laser Please contact NG CEO for detailed information Optimize Laser Performance Optimization of the laser may be required when the laser is initially installed or the laser performance has degraded due to aging laser diodes For this procedure a green light should be visible from the laser In the absence of any visible output please review Chapter 7 Troubleshooting or contact NG CEO for assistance To obtain the best performance small adjustments may optimize the laser To optimize the laser follow these steps
14. Interface Table 3 2 2 Connections Pin Signal Description A Array Drive Positive Divide current with Pin B Voltage and current per test report Approximately 20V and 25A B Array Drive Positive Divide current with Pin A Voltage and current per test report Approximately 20V and 25A C Array Drive Negative Divide current with pin D Array Drive Return D Array Drive Negative Divide current with pin C Array Drive Return Connector Part Number MS3476L14 4S Backshell Part Number M85049 52 1 14N Northrop Grumman Corporation 15 Ikiwa Laser User Manual Chapter 3 System Details Closed Loop Chiller The single most common cause of a laser returned for repair involves customer damage More than one third of these damaged lasers result from cooling problems Coolant problems almost always require the replacement of the diode arrays the single most expensive component in NG CEO lasers This section describes how to avoid damaging arrays WARNING Do not operate laser without cooling Do not power the laser diodes or Q switch without cooling Inadequate heat dissipation will seriously damage the laser diodes or Q switch and will void warranty Table 3 3 Heat Capacity and Minimum Flow Rate Heat Capacity Minimum Flow Rate 1 5 gpm 5 7 lpm IKA 012 QTG IKA 016 QTG 1 Heat capacity should be greater than the laser s power consumption Northrop Grumman Corporation 16 Ikiwa Laser User Manual C
15. S PROVIDED IN THIS SUMMARY OR THE APPLICABLE WARRANTY STATEMENT NG CEO MAKES NO WARRANTY OF ANY KIND EXPRESS OR IMPLIED INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PUPOSE IN NO EVENT SHALL NG CEO BE LIABLE FOR INDIRECT SPECIAL OR CONSEQUENTIAL DAMAGES Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of NG CEO Trademarks Iklwa is a registered trademark of Northrop Grumman Corporation Patents Northrop Grumman Corporation products are covered by U S and foreign patents issued and pending Information in this publication supersedes that in all previously published material Specifications and price change privileges reserved Northrop Grumman Corporation il Ikiwa Laser User Manual Safety Information Product End of Life Handling NG CEO is committed to protecting the environment In accordance with the Waste Electrical and Electronic Eguipment directive WEEE and Restriction of Hazardous Substances in the European Union RoHS EU directives NG CEO accepts the return of our products for disposal When you are ready to reclaim the instrument you must properly transfer it according to local regulations concerning WEEE eguipment Contact NG CEO
16. Supplied Cooling Closed Loop Recirculating Chiller Coolant 10 Optishield Plusty 90 distilled water Recommended Operating Temperature 18 30 C Laser head size 24 Lx 6 H x 8 W 1 Chiller must be able to circulate coolant at the approximately 60 psi required in NG CEO lasers see final test report for each laser specific required pressure Drain the chiller and replace the coolant and filter monthly This may be required more often if the system shows signs of contamination Electronic Interface Diode Drive power supply TEC Controller for second harmonic generator crystal temperature control A O Q Switch RF Driver Northrop Grumman Corporation 4 Ikiwa Laser User Manual Chapter 1 Introduction Shutter control Laser on Indicator Cover Interlock Water flow interlock NG CEO will provide the required current voltage chiller temperature and TEC temperature set points on the test report supplied with the laser Thermal Control Subsystem Thermal control and heat removal from the laser transmitter is accomplished by the chiller The laseris equipped with an integral flow switch that should be used to interrupt drive current to the amplifier module and power to the Q switch when the flow rate falls below 1 gpm 3 8 Ipm Flow direction is labeled on the laser optics housing below the coupler ports Please observe the flow direction at all times Please see the chiller set up section for more details The thermal
17. Triggering and FPS E 31 Chapter 5 Maintenance 32 Prepare for Shipment eeneg ebe egegeddtEE ege 33 Purge ee EE 33 Northrop Grumman Corporation D Ikiwa Laser User Manual Table of Contents Replace Desiccant Cartridge 230 iet feu ges EEEEL EENS SOERENSEN kakaa ki kiana 34 Maintain CM geome eee eed ae eae Ree ne ap ert ear een epar ae tree eter ira eat ore ete erin A ere a Cone tr 35 Ch ck Hold eege ege 35 Extend Hif time of Laser DI ISI nsure Save coved ikakaa kuli kaliwa 36 Optimize Laser Genee 36 Chapter 6 Customer Service 41 Contacting Re en Te 42 Module Roi EE 42 Return the Instrument for Repair seed 42 Chapter 7 Troubleshooting 44 er ere E 45 Laser Output Eed 45 Appendix A Customer Service 47 TN EE 48 Appendix B System International Units 50 Appendix C Acronyms 51 Index 53 Northrop Grumman Corporation X Ikiwa Laser User Manual List of Figures and Tables Listof Figures and Tables Table 1 1 Other Specifications Table 4 Figure 2 1 Radiation COnuol s va a nasnatan asa alana Aas a aaa 9 Figure 3 1 Ikiwa Front View ee ee EES 11 Figure 3 2 Ikiwa Rear View 11 Figure 3 3 kiwa TOO EE 12 Figure 3 4 Ikiwa J1 Connector Interface sees 13 Table 3 1 J1 Connections EE 14 Figure 3 5 Ikiwa J2 Connector Interface niwa wiii nnn 15 Table e 15 Table 3 3 Heat Capacity and Minimum Flow Hate 16 Table 3 4 Cooling System Requirements mumu zanununi tumaini 17 Table 3 5 Avoid with Chillers mwm eee 17 Figure 3 9 C
18. User Manual IKLWA Laser Head May 2013 NORTHROP GRUMMAN 1 CEO UMAN 0055 Rev A Worldwide Technical Support and Product Information www northropgrumman com Search ceolaser Hours 8 00 a m to 5 00 p m Central time Technical Support 636 916 4900 follow prompts for department directory Email ngceoservice ngc com Cutting Edge Optronics Headquarters 20 Point West Blvd St Charles MO 63301 USA Sales Support 636 916 4900 follow prompts for department directory After office hours please leave a voice mail message Outside North America contact a Cutting Edge Optronics sales office or distributor see the Cutting Edge Optronics website for a list of offices 2006 2013 Cutting Edge Optronics a strategic business unit of Northrop Grumman Corporation All rights reserved Northrop Grumman Corporation i Ikiwa Laser User Manual Important Information Warranty Summary Northrop Grumman Cutting Edge Optronics NG CEO warrants that the products that it manufactures and sells will be free from defects in materials and workmanship for a period of one year from the date of shipment from an NG CEO distributor If a product proves defective within the respective period NG CEO will provide repair or replacement as described in the complete warranty statement To arrange for service or obtain a copy of the complete warranty statement please contact your nearest NG CEO sales and service office EXCEPT A
19. al lensing which is related to the operating current Variation of the operating current results in the change of the thermal lensing Therefore the Northrop Grumman Corporation 29 Ikiwa Laser User Manual Chapter 4 Installation and Operation position of the focal point moves as the pump current is varied This is not desirable for most laser applications especially laser micro machining The output power of Ikiwa laser can be changed either by changing the operating current or by changing the O switch power This unigue patented technology allows users to adjust the laser output power continuously without changing the operating current The focal point is kept at the same position regardless of the power level This feature is very useful for precision micro machining reguiring different power levels to complete the process Northrop Grumman Corporation 30 Ikiwa Laser User Manual Chapter 4 Installation and Operation External Triggering and FPS The laser may be externally triggered using a TTL signal of 300 ns to 500 ns duration Figure 4 9 illustrates the RF signal output to the Q switch without first pulse suppression FPS and the laser pulse train with the first giant pulse If the peak power of these giant pulses is high enough it can cause the damage to the mirrors and the laser crystals The giant pulse forms when the lasing was stopped while the pumping light is still on during the laser processing cycle The amplitude
20. an Corporation 1 Ikiwa Laser User Manual Chapter 1 Introduction Theory of Operation Ikiwa Laser is a Q switched intra cavity frequency doubled laser oscillator The output consists of pulses of light at 532 nm wavelength and 60 ns to 100 ns pulse duration at repetition frequencies of 4 000 Hz to 10 000 Hz It is a transverse electromagnetic mode TEMO0 laser and therefore has very high brightness The continuous wave CW pumped neodymium doped yttrium aluminum garnet Nd YAG rod module in the oscillator is optically excited using arrays of laser diode bars operating at wavelengths around 806 nm A laser oscillator consists of an optical amplifier in an optical cavity which forms a laser optical mode that can oscillate when the gain of the amplifier is sufficient to overcome the losses in the optical cavity One such loss is the amount that escapes the oscillator cavity through one of its mirrors resulting in its useful output This basic approach suffices unless the output beam at a desired wavelength differs from the fundamental wavelength 1 064 nm of the laser amplifier medium Nd YAG Various nonlinear optic techniques can serve to convert this beam to another wavelength but usually with considerable loss of power or with a residue of unconverted fundamental power This occurs when the fundamental radiation is allowed to leave the oscillator cavity and the beam is converted outside the cavity However if the nonlinear conversion i
21. an be controlled The performance parameters are optimized with a crystal temperature between 20 C Northrop Grumman Corporation 2 Ikiwa Laser User Manual Chapter 1 Introduction to 50 C Once this temperature is identified and fixed the temperature of the crystal can be stabilized to 0 1 C with the TEC controller The Nd YAG laser amplifier is capable of storing a considerable amount of energy due to the long upper state lifetime of the Nd ion The Iklwa laser uses an acousto optic AO Q switch to prevent the buildup of optical power in the oscillator cavity by introducing a loss greater than the available gain allowing energy to accumulate in the gain medium The Q switch then suddenly removes the loss allowing the laser power to increase exponentially with each round trip of the oscillator cavity until much of the stored energy is exhausted and the gain once again falls below the loss It takes light only a few nanoseconds to transit the laser cavity and results in releasing stored energy in a short duration pulse The high peak power achieved in this manner is also essential to achieving an adequate fraction of conversion to 532 nm The conversion process is dependent on the intensity of the circulating 1064 nm power The laser beam that circulates inside the oscillator cavity is determined by a process of self consistency The beam characteristics at any given location in the cavity are repeated after the beam completes a round
22. anual This chapter covers Unpacking the laser system Laser head setup Chiller setup Connections to the laser head First Time Laser Power up procedure Daily operation Output power control External triggering and FPS The purchaser is responsible for any loss and injury during installation and use of the laser system NG CEO recommends that a qualified service technician install and maintain the laser If you intend to service the laser yourself please follow the following procedures Northrop Grumman Corporation 21 Ikiwa Laser User Manual Chapter 4 Installation and Operation Unpacking The Laser System Your NG CEO Ikiwa laser was carefully packed for shipment If the carton appears to have been damaged in transit have the shipper s agent present when you unpack Inspect the unit as you unpack it looking for dents scratches or other evidence of damage If you discover any damage immediately file a claim against the carrier and notify your NG CEO representative NG CEO will arrange for repair without waiting for settlement of your claim Keep the shipping container If you file a damage claim you may need it to demonstrate that the damage occurred as a result of shipping If you need to return the unit for service the specially designed carton assures adeguate protection Laser Head Setup The laser head should be mounted on an optical table or eguivalent strong flat surface Three mounting hole
23. e Closed loop chiller Northrop Grumman Corporation 10 Ikiwa Laser User Manual Chapter 3 System Details Ikiwa Laser Head The Ikiwa laser head measures 24 inches by 8 inches by 6 inches not including the connectors at the rear of the laser The laser emission indicator is located on the side of the unit The output window is positioned 76 2 mm 3 inches from the bottom of the Iklwa laser and 99 7 mm 3 93 inches from the side with the emission indicator Laser Emission Light 14 D p H p IX ZIN pi ja bf o d No Nae Optional Right Hand Output Window Left Hand Output Window Figure 3 1 Ikiwa Front View The rear panel of the Iklwa laser has connectors for electronic control The coolant in and coolant out ports are also found on the back panel Purge Valve Opening Figure 3 2 Ikiwa Rear View The alignment openings are located on both front and back panels and are sealed by screws to prevent emission during normal operation The service technician can remove the screws and use a HeNe laser to aid alignment Northrop Grumman Corporation 11 Ikiwa Laser User Manual Chapter 3 System Details WARNING The screws filling the alignment hole are considered non interlocked covers If the screws are not replaced and the Ikiwa laser is running the opening will function as an aperture It can allow an output beam of up to 3 W at the same rep rate and pulse width as the main beam This beam would be capable of
24. e pumped amplifier medium s diameter and focal power Once the design parameters are selected for optimum fundamental mode operation they cannot be altered without disrupting the fundamental mode size in the amplifier leading to unacceptable changes in performance This is particularly important to the intensity of amplifier excitation pump power or drive current Northrop Grumman Corporation 3 Ikiwa Laser User Manual Chapter 1 Introduction since these also determine focal power Conseguently the amplifier drive current must be kept within a close tolerance of the design point In applications that reguire the laser output power be lowered to reduce gain without sacrificing beam characteristics and focal power the Ikiwa laser achieves a corresponding reduction of power by increasing the loss of the optical cavity while maintaining the gain at a constant level System Description The Ikiwa laser consists of three interconnected subsystems The optics subsystem contains the laser oscillator The diode power supply supplies current to the diodes The chiller provides thermal control The user must supply prime power and cooling to the optics subsystem Refer to the NG CEO web site www northropgrumman com Search ceolaser or your quotation for performance specifications for the particular laser that you have purchased Table 1 1 Other Specifications Table Parameter Performance Electrical Inputs Customer
25. ect fittings are locked by listening for a clicking sound Figure 4 5 Plumbing Connection 2 Connect RF Cable Connect the Q switch RF cable to the BNC connector on the laser head see Figure 4 6 Once it is aligned the connector can be pushed in Turn the locking ring of the connector in the clockwise direction until it is locked Northrop Grumman Corporation 25 Ikiwa Laser User Manual Chapter 4 Installation and Operation Figure 4 6 RF Connection 3 Connect diode power Remove the white jumper wire and connect the female connector of the diode power cable to the J2 connector on the laser head see Figure 4 7 Once it is aligned the connector can be pushed in Turn the locking ring of the connector in the clockwise direction until it is locked Figure 4 7 Diode Power Connection 4 Connect laser signal Align the female connector of the laser signal cable to the JI connector on the laser head Once it is aligned the connector can be pushed in Turn the locking ring of the connector in the clockwise direction until it is locked as shown in Figure 4 8 Northrop Grumman Corporation 26 Ikiwa Laser User Manual Chapter 4 Installation and Operation Figure 4 8 Signal Connection First Time Laser Power Up Procedure Remove the cap that protects laser output window and make sure the window is clean If not gently clean it with a lens tissue and methanol Turn on the chiller and verify its settings 1 Tur
26. ect water flow path starts with the supply port of the chiller gt filter gt coolant in port of laser head gt laser head gt coolant out port of laser head gt return port of the chiller Please be aware of the flow direction of the filter Northrop Grumman Corporation 23 Ikiwa Laser User Manual Chapter 4 Installation and Operation Figure 4 2 Water Hoses and Filter Connections The filter may be attached to the back of the chiller customer s equipment or a wall using the provided L bracket NOTE Threaded hose barbs and adapters should have threads wrapped 3 4 times with Teflon tape Figure 4 3 depicts the chiller with connected water hoses Figure 4 3 Chiller Assembled with Water Hoses and Filter Connections to the Laser Head Figure 4 4 depicts the connectors on the rear panel of the Iklwa laser All of the connectors are clearly labeled Northrop Grumman Corporation 24 Ikiwa Laser User Manual Chapter 4 Installation and Operation COOLANT IN BD Figure 4 4 Connectors on the rear panel of the Ikiwa laser Follow these steps to connect the laser head 1 Connect plumbing As shown in Figure 4 5 push the barb fittings of water hose connectors gently into the coolant in and coolant out ports by following the flow path direction Wetting the o rings of the quick disconnect fittings and receptacles can prevent the o ring from being damaged Make sure that the quick disconn
27. ed after optimization contact NG CEO for service No Output Power Laser Flicker Verify the operating current is set at the operation point Verify the Q switch is set to hold off and the laser is triggered at preset PRF with an internal or external triggering source Verify the shutter is open Verify there are no interlock warning messages Verify the Q Switch controller settings When the external perturbations are applied to the laser system the laser exhibits flickering Northrop Grumman Corporation Verify the laser performance is optimized Verify there is no strong vibration forces applied to the laser head Verify that the flow rate to the laser head is above 1 5 GPM and the coolant flow is not intermittent Verify the laser has good output power A laser with high modulation loss or low operating current is sensitive to perturbations Verify the operating current is stable Verify the Q switch hold off is good 46 Ikiwa Laser User Manual Appendix A Customer Service This form has been provided to encourage you to tell us about any difficulties you may have experienced while using your Northrop Grumman Cutting Edge Optronics instruments or user manuals Call or write our customer service department to bring attention to problems that you may not have personally experienced We are always interested in improving our products and manuals and we appreciate all suggestions Date Name C
28. em crash Initial Capped The first letter in uppercase refers to menu options e g Phase Delay Pulse Width CAPS Front panel buttons knobs and connectors appear in all uppercase letters e g MENU CURRENT gt The gt symbol separates a sequence of button pushes e g MENU gt CHANNEL SETUP gt PULSE WIDTH means that you push the MENU button then push the CHANNEL SETUP soft key and then push the PULSE WIDTH soft key italic Italic text denotes references to other resources that may be helpful to you or to bring attention to important information This icon denotes a note which alerts you to important information et Power Switch Position Symbols O I On O Off The following conventions may appear on the product DANGER An injury hazard immediately accessible as you read the marking WARNING 4 hazard not immediately accessible as you read the marking CAUTION A hazard to property including the product ESD Handle Appropriately Northrop Grumman Corporation V Ikiwa Laser User Manual Laser Emission Use caution Shock Hazard Use caution Caution Risk of danger Refer to manual Chassis Ground Northrop Grumman Corporation vi Ikiwa Laser User Manual General Safety Summary The Ikiwa Laser System emits laser radiation that can permanently damage eyes and skin ignite fires and vaporize materials Chapter 2 Laser Safety contains information and guidance about these
29. gger and to the frequency specified on the test data sheet Verify the chiller set point temperature and flow rate are correct Operate the laser and for at least 20 minutes to reach full power and stability before making any adjustments Only after verifying these conditions should you attempt to make adjustments to the laser system Laser Output Power Low Output Power 0 01 W 12 W Low Q switch power Check the setting of the Q switch driver Problem with power meter Use another power meter to verify the measurement Low operating current Check the set current and actual current A too high or low current setting will result in low power Water temperature not set Verify the chiller is set to provide the correct water flow rate and temperature to the laser head Phase matching condition of SHG crystal is not met Check the temperature of TEC controller and make sure it works properly Northrop Grumman Corporation 45 Ikiwa Laser User Manual Chapter 7 Troubleshooting Laser is running in CW mode or problem with hold off Check the hold off of the laser Pulse repetition rate is not correct Check the pulse rate freguency PRF Laser is misaligned Perform the laser power optimization procedures as described in the Optimize Laser Performance section in Chapter 5 Maintenance to bring the power back Internal optical damage to the laser contaminated rod or aging diodes If the laser power cannot be restor
30. hapter 3 System Details Table 3 4 Cooling System Reguirements Chiller and Cooling System Reguirements Capable of recommended flow rate at 60 psi Optishield Plus mixed with distilled water per manufacturer s instructions Filter connected between chiller and inlet on laser Chiller Heat Capacity gt Laser Power Consumption Flow sensor installed internally on Ikiwa lasers Replace coolant and filter monthly 1 The actual operating pressure should be lower than 60 psi It is acceptable if your chiller can achieve the required minimum flow rate through the laser with a lower water pressure typically around 55 psi Clean coolant keeps coolant lines from clogging Untreated tap water may cause damage Suitable coolants include Optishield Plus from Opti Temp Inc Traverse City Mich 231 946 2931 3 The filter should be capable of removing particles 5 um or larger The filter and coolant should be replaced each month or more frequently if the pH drops below 9 or the filter or coolant show any discoloration When not using NG CEO drive electronics verify that flow sensor interrupts current to diodes less than 1s after a low flow condition occurs Table 3 5 Avoid with Chillers Avoid with Chillers De ionized water Iron or aluminum parts in plumbing loop Operation below air condensation temperature 1 The Ikiwa laser has exposed bare copper inside the coolant loop F
31. iewing of the beam or its specular reflection Follow the instructions contained in this manual for proper installation and safe operation of your laser We recommend the use of protective eyewear at all times the type of eyewear depends on the energy and wavelength of the laser beam and operating conditions Consult ANSI ACGIH or OSHA standards for guidance CAUTION Use of controls adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure WARNING At all times during installation operation maintenance or service of your laser avoid exposure to laser or collateral radiation exceeding the accessible emission limits listed in Performance Standards for Laser Products U S Code of Federal Regulations 21 CFR 1040 10 d CAUTION The laser diodes in the IKLWA laser head are sensitive to Electro Static Discharge ESD Never handle the laser without being properly grounded through the use of properly installed and maintained grounding wrist straps or other ESD control devices Subjecting the IKLWA laser to static shock can seriously damage or destroy the diode bars and will void the product warranty WARNING The voltages in this system can be harmful or even lethal Whenever handling or servicing the laser always disconnect the power cord to the power supplies and drivers Allow at least five 5 minutes for all electronics to discharge before touching or grounding of elect
32. iltered air or N2 is recommended 2 Remove coolant connections from back of laser housing 3 Connect a dry gas line to the COOLANT OUT connector on housing Coolant lines must be purged in the proper direction or trapped water may remain in the lines inside the laser If this trapped water freezes it can cause lines to leak water when operation is resumed 4 Connect a drain hose with a proper quick disconnect fitting to the COOLANT IN connector on the housing 5 Purge the lines with for at least 1 2 hour at 5 psi 6 Remove purge lines After the laser is dry place it in a sealed ESD bag with a desiccant Package the laser securely in a shipping container You will need to remove all water from the chiller prior to shipment Refer to the chiller manufacturer s instructions Do not reconnect chiller lines to laser prior to shipment After shipment if antifreeze was used drain and clean the chiller Add a new filter and clean Optishield Plus coolant before reconnecting the chiller to the laser Purge Housing The Iklwa optics assembly must be kept at low humidity to protect the SHG crystal which is slightly hygroscopic and to prevent the possibility of condensation on the laser diode arrays The Iklwa housing provides a level of protection from entry of ambient humidity but it is not hermetically sealed When operating in a high ambient humidity precautions need to be taken to keep the interior of the housing dry The lid
33. in the shipping container WARNING Damage from residual water due to condensation or expansion can be catastrophic to the diode arrays or laser rod if not dealt with properly Such damage is excluded from warranty coverage Northrop Grumman Corporation 43 Ikiwa Laser User Manual Chapter 7 Troubleshooting This chapter is intended to provide possible solutions to common problems encountered with the Iklwa laser during normal use For more information please see the troubleshooting guide that is on the owner s manual CD supplied with the laser WARNING Do not attempt repairs while the unit is under warranty Complete the form in Appendix A and report problems to NG CEO for repair The following sections can be found in this chapter Initial checklist Laser output power Northrop Grumman Corporation 44 Ikiwa Laser User Manual Chapter 7 Troubleshooting Initial Checklist Before adjusting or attempting troubleshooting procedures verify the following Additional information is available in the troubleshooting guide that was supplied with your laser Verify the diode current supply is operating at the correct output current and the current set point matches the test data sheet supplied with the laser Verify that the TEC Controller is set to the temperature specified on the test data sheet supplied with the laser Ensure that the Q switch is enabled Verify the Q switch is set to internal tri
34. l Health Continuous Wave First Pulse Suppression Helium Neon Harmonic Mirror High Reflection International Electrotechnical Commission Lithium Triborate Nitrogen Neodymium Doped Yitrium Aluminum Garnet Nanometer Occupational Safety and Health Administration Pulse Rate Frequency 51 Ikiwa Laser User Manual Appendix C Acronyms Acronym Description PSI Pounds per Square Inch RF Radio Frequency RH Relative Humidity RMS Root Mean Square SHG Second Harmonic Generator TEC Thermal Electric Cooler TEMOO Transverse Electromagnetic Mode TTL Transistor Transistor Logic UV Ultraviolet VAC Volts Alternating Current Northrop Grumman Corporation 52 Ikiwa Laser User Manual Index BNC 25 caution vi chassis ground vi chiller 4 5 16 18 23 24 26 27 28 29 31 32 34 35 44 47 Chiller 4 5 16 21 23 24 34 46 Cleaning 23 Condensation 17 18 20 27 34 contacting Cutting Edge Optronics ii Coolant 4 5 16 32 Cooling 4 16 Customer Service vii viii 40 41 46 desiccant 18 20 31 32 33 34 42 Desiccant 33 Diode 26 eDrive 46 end of life handling iv ESD v EU directives iv filters 23 flow switch 5 ground chassis vi Northrop Grumman Corporation Index Hold Off 34 39 laser emission Vi Laser Safety vii viii 6 Module 40 41 negative lens 22 27 Optishield 16 32 plumbing 23 25 power cable 25 power meter 22 27 34 39 44 Purge 31 32 Q switch
35. n A Laser On LED Laser on lamp on the laser housing Requires 24 V Positive Keep isolated from other circuits B Laser On LED Laser On LED Positive Return Negative C Shutter Drive Positive 24 V for a brief energize period and drop to 12 Vayg for continuous duty Can be pulse width modulated D Shutter Drive Shutter Drive Positive Return Negative H Cover Interlock 1 Continuity to pin X indicates that the cover is properly closed X Cover Interlock 2 Continuity to pin H indicates that the cover is properly closed J Flow Switch 1 Continuity to pin R indicates that the interlock is closed R Flow Switch 2 Continuity to pin J indicates that the interlock is closed K Not Used K shorted to a for CEO test electronics a Not Used a shorted to K for CEO test electronics b LBO Oven RTD 1 To Oven Industries temperature sensor control pin 1 CG LBO Oven RTD 2 To Oven Industries temperature sensor control pin 3 G TE Cooler Drive POS To Oven Industries Terminal 2 TE Cooler Drive NEG To Oven Industries Terminal 1 Connector Part Number MS3476L16 26S Backshell Part Number 380AS001M1610M3 Northrop Grumman Corporation 14 Ikiwa Laser User Manual Chapter 3 System Details LASER DRIVE CONNECTOR MS3476L14 4S M85049 52 1 14N LASER DRIVE CONNECTOR ARRAY DRIVE POS ARRAY DRIVE NEG ELECTRONIC ARRAY DRIVE POS NTE R FACE ARRAY DRIVE NEG Figure 3 5 Ikiwa J 2 Connector
36. n on the chiller 2 Check the temperature setting of the chiller Refer to the test report included in your Iklwa laser shipment for the coolant operational temperature The chiller s temperature setting should be the same as in the report If it is set to a different temperature change it to match the setting on the report 3 The minimum flow rate for Iklwa laser is 1 5 gpm Ensure the flow rate meets the requirement If it does not open the valve inside the chiller until it matches the flow rate recorded in the test report 4 Run the chiller for approximately 2 hour to allow it to stabilize at the set temperature WARNING Do not operate coolant system below air condensation temperature dew point at the laser head Condensation on the diode arrays can seriously damage the laser head Northrop Grumman Corporation 27 Ikiwa Laser User Manual TEC Controller Chapter 4 Installation and Operation 1 Verify that all connections from the laser to the controller are complete 2 Verify that the temperature has been set to the value on the NG CEO supplied test sheet Turn on the power per the manufacturer s instructions 4 Wait for several minutes to see if the actual temperature is stabilized at the set temperature If so then go to the next step WARNING Do not set the temperature of SHG below air condensation temperature dew point at laser head Condensation on the SHG crystal can seriously damage the crystal
37. of the housing has a port for a desiccant cartridge which should be changed when the cartridge indicator is no longer blue Also the housing interior can be purged with zero air using the valve on the rear of the housing The inlet line is the stemmed valve and is opened and closed by rotating the knob on the valve end Please contact NG CEO before attempting this procedure Northrop Grumman Corporation 33 Ikiwa Laser User Manual Chapter 5 Maintenance CAUTION The clean dry air input line must be on a pressure regulator and the line must be filtered Replace Desiccant Cartridge The desiccant cartridge as shown in Figure 5 1 removes excess moisture from inside the laser head It is located on the lid of the Iklwa laser head The desiccant cartridge must be replaced regularly so it should be checked at least weekly for exhaustion Exhaustion is indicated by a change in the color of the indicator paper in the top of the cartridge While any sector of the indicator paper in the cartridge top remains blue the cartridge can still absorb water When all three sectors of the indicator paper turn completely white or light pink the module has absorbed all the water it can and must be replaced Replacement frequency varies with the humidity in your operating environment and if the laser head is opened If the desiccant cartridges are exhausted in a short time frame e g two weeks without the laser head having been opened contact NG CEO
38. ompany or Institution Department Address Laser Model Number Serial Number Chiller Model Number Serial Number eDrive Model Number Serial Number Laser Manufacture Date Total Laser Lifetime hours Northrop Grumman Corporation 47 Ikiwa Laser User Manual Questions What is the water flow rate GPM Appendix A Customer Service What is the set temperature on the chiller C What is the water pressure on chiller PSI What are the temperature set and actual reading from TEC controller C What are the set current and actual current A Is Q switch enabled yes no Is Q switch triggered internally or externally What is the Q switch power percent Is FPS enabled yes no What are the FPS parameters What is the pulse repetition frequency kHz Is the output power measured directly from the laser yes no What is the measured power W When did the problem happen Have you changed any settings recently yes no Have you adjusted the laser to try to fix the problem yes no Northrop Grumman Corporation 48 Ikiwa Laser User Manual Appendix A Customer Service Whatare the changes made recently to the system Please describe the problem or laser behavior as detailed as possible Suggestions Email or far to Northrop Grumman
39. onstant Dew Point Lines for Ambient Temperature and Relative Humidity 19 Table 3 6 Table of Air Condensation Temperature at Given Ambient Air Temperature Celcius and Relative Humidity percent ee 20 Figure 4 1 Setup for the laser power fest 23 Figure 4 2 Water Hoses and Filter Connections ssseeeeeeerererenn rr 24 Figure 4 3 Chiller Assembled with Water Hoses and Filter sssssseeeeeerrrn renerne 24 Figure 4 4 Connectors on the rear panel of the Iklwa laser sssssseeeeeeeernnr reen 25 Figure 4 5 Plumbing Connection sci iia es ein eds Sees Bae ei ea ner 25 Figure 4 6 RF Connection wi mumuwunanunutu tumikia wizi 26 Figure 4 7 Diode Power CGonnechon EEN 26 Figure 4 8 Signal Connection EE 27 Northrop Grumman Corporation xi Ikiwa Laser User Manual List of Figures and Tables Figure 4 9 First Giant Pulse with FPS Disabled A 3i Figure 5 1 Desiccant Cartridge 2 ieee ee ww wanuni ener 34 Figure 5 2 Example of Power Dependence and Pulse to Pulse Instability of the laser to GHG Crystal Terre rn 37 Figure 5 3 Example of Laser Performance Dependence on the Operating Current 38 Figure 5 4 Accessible Holes for HR and HM Cavity Mirror Adjustment ss 39 Northrop Grumman Corporation vii Ikiwa Laser User Manual Chapter 1 Introduction This introduction provides the following information Theory of operation System description Northrop Grumm
40. or this reason NG CEO does not recommend using untreated dionized DI water If DI water is used as the coolant it is important to maintain the water resistivity between 300 and 700 K ohms and to keep the water slightly basic i e keep the water above 8 0 pH The Ikiwa laser is environmentally sealed but not hermetically sealed Atmospheric conditions near the exterior of the laser will mimic conditions inside laser head Northrop Grumman Corporation 17 Ikiwa Laser User Manual Chapter 3 System Details Operating the Chiller WARNING Do not operate laser without cooling Inadequate heat dissipation will seriously damage the laser diodes and will void warranty If you notice water in the immediate vicinity of the laser shut the laser system down immediately Check to see if the water is coming from the laser head If so return the laser for repair If not repair the source of the leak and allow the unit to dry thoroughly before resuming operation The laser system has a coolant loop to prevent thermal damage to the laser diodes The diodes should be kept at approximately 20 C to 35 C See the final test report included with your laser for optimum temperature and flow rate settings Operating the laser diodes for even a short period of time less than one second without coolant will cause permanent damage To help prevent this the Iklwa laser is equipped with an internal flow switch interlock Customer supplied electronic
41. orporation 28 Ikiwa Laser User Manual Chapter 4 Installation and Operation CAUTION The output beam of this system is a safety hazard Avoid viewing the beam directly Turn On Procedure 1 Switch the chiller to the ON position Verify correct flow rate and temperature setting to value specified on laser test report Wait until chiller has achieved proper temperature which may take 5 to 10 minutes 2 Turn the TEC controller and wait for the temperature to stabilize 3 Verify the current and Q switch settings 4 Supply current to the laser diodes 5 Open the shutter to begin laser output Wait for about 20 minutes to reach 95 percent of nominal output power Manual Interrupt Procedure 1 Close the shutter 2 Resume operation by opening the shutter again Laser will resume operation with no audible warning NOTE The laser diodes are operated at set pumping current while the shutter is closed Shut Down Procedure 1 Close the shutter to stop lasing 2 Turn off the diode drive current The laser diodes cease emission 3 Turn off TEC controller 4 Turn off chiller Output P ower Control Every laser application requires specific laser power settings for the best results In some cases the output power has to be changed at different stages even in the same laser process Typically the output power of a laser can be varied by changing the operating current However the active laser crystals can exhibit strong therm
42. pliance This laser component contains warning labels an internal shutter laser on light and cover interlocks If it is sold as an OEM laser component compliance with Title 21 of the U S Code of Federal Regulations Chapter 1 Subchapter J Part 1040 10 and 1040 11Is dependent on the customer supplied control system If it is sold with NG CEO s electronic system it complies with the regulations Northrop Grumman Corporation 8 Ikiwa Laser User Manual Chapter 2 Laser Safety Cutting Edge Optronics Inc 20 Point West Boulevard St Charles MO 63301 MANUFACTURED MODEL NUMBER SERIAL NUMBER This is an OEM laser product complies with 21 CFR 1040 as applicable when operated with compliant electronics DANGER MADE IN U S A Non Interlocked Protective Housing DANGER Laser radiation when open F FE AVOID EYE OR SKIN EXPOSURE TO Certification and Identification Label DIRECT OR SCATTERED RADIATION Non Interlocked Housing Label Class lV Danger Label Avoid Exposure Label Defeatably Interlocked Protective Housing DANGER Laser radiation when open and interlock defeated AVOID EYE OR SKIN EXPOSURE TO DIRECT OR SCATTERED RADIATION Defeatable Interlocked Housing Label Figure 2 1 Radiation Control Northrop Grumman Corporation 9 Ikiwa Laser User Manual Chapter 3 System Details This chapter discusses the operation of the Ikiwa laser Ikiwa laser head Ikiwa wiring interfac
43. r HR and HM Cavity Mirror Adjustment e Optimize power Make small adjustments to the horizontal angle of HM mirror and observe the output power Once a maximum is found adjust the vertical control of HM mirror to maximize power Make small adjustments to the horizontal angle of HR mirror and observe the output power Once a maximum is found adjust the vertical control of HR mirror to maximize power Repeat the optimization steps with both the HR and HM until there is no significant performance improvement If the laser is still not within 5 of the original power or not stable repeat the steps of TEC optimization current optimization and HM HR adjustment until there is no significant performance improvement If the laser power can t be restored to the specification or the laser is not stable then the walking the cavity procedure can be tried Walking the cavity is sometimes required to optimize the laser and involves combining mirror mount and SHG crystal temperature adjustments e Reduce current by 2 A while making coarse adjustments Return current to normal when making fine adjustments e Makea horizontal adjustment to the HM mount Recover the laser power by making a similar adjustment to the horizontal control of the HR mount Check and adjust the temperature of SHG crystal 39 Ikiwa Laser User Manual Northrop Grumman Corporation Chapter 5 Maintenance Continue if improvement is noted If there i
44. ration Chapter 4 Installation and Operation discusses how to unpack setup and powering on your system for the first time Chapter 5 Maintenance provides information on proper maintenance of your laser system Chapter 6 Customer Service provides resources to help fix problems with the Ikiwa laser Chapter 7 Troubleshooting provides possible solutions to the most common issues Appendix A Customer Service provides information to expedite any service request before contacting NG CEO Appendix B System International Units identifies commonly used units of measurement found in this manual Appendix C Acronyms provides a list of commonly used abbreviations and their descriptions used throughout this manual viii Ikiwa Laser User Manual Table of Contents Table of Contents Chapter 1 Introduction 1 ONE Ee 2 System Klees 4 Chapter 2 Laser Safety 6 SEENEN 7 Precautions for Safe Operation EE 7 Center for Devices and Radiological Health Compliance cccccececceeeeneeeeeeeeeeeeeeeetneeeeeeeees 8 Chapter 3 System Details 10 ikwa baser KE 11 Ikiwa EELER 13 Closed Loop Chiller ee 16 Chapter 4 Installation and Operation 21 Unpacking The Laser Sy D 22 Laser Fleege Seeerei 22 n Tee VE 23 Connections tothe Laser Medd kaa 24 First Time Laser Power Up Procedure siicccdatccscadstacsay leveled hacctedeizcsancatees talete case ihadtinexecieociuncd 27 Daily Operatio EE 28 Output FOweEr Control EE 29 External
45. rical connections Precautions for Safe Operation Avoid looking directly into the laser beam or at specular reflection even with protective eye wear on Wear laser safety eyewear that is optically dense at the wavelengths of operation 798 816 nm pump light 1064 nm fundamental 532 nm second harmonic Provide a controlled access area for laser operation and limit access to those trained in laser safety principles Northrop Grumman Corporation 7 Ikiwa Laser User Manual Chapter 2 Laser Safety Post warning signs in prominent locations near the laser operation area Use safety interlocks on all entryways All NG CEO system control electronics are supplied with interlock inputs that can be used to preclude operation with an open safety door Enclose beam paths wherever possible Set up experiments so the laser beam is below eye level Work in an area that is well lighted to avoid dilation of pupils Set up a target for the beam Set up shields to prevent reflected beams from escaping the laser operation area View an infrared laser beam with a protected image converter at an oblique angle reflecting from a diffuse surface Ensure that all electrical connections are made in a safe manner Position equipment so that electrical connections are shielded from accidental touch Do not smoke eat or drink in laser areas Avoid leaving an operating laser unattended Center for Devices and Radiological Health Com
46. s are provided to secure the laser The laser should be installed in a clean environment A power meter with the ability to handle a minimum of 30 W should be installed approximately 1 5 feet away from the laser in the direction of the laser output beam To protect the power meter a negative lens f 100 mm with an anti reflective AR coating at 532 nm should be installed in front of the power meter as shown in Figure 4 2 below If a negative lens is not available the power meter should be at least 2 m away from the laser so that the beam size is larger and the power density is below the damage threshold of the power meter A pulse detector should be positioned as shown in Figure 4 2 to verify the pulse characteristics of the laser Northrop Grumman Corporation 22 Ikiwa Laser User Manual Chapter 4 Installation and Operation Figure 4 1 Setup for the laser power test Chiller Set Up Chiller Cleaning Procedures Please follow the proper procedures to clean the chiller before it is connected to the laser head These procedures are listed on the CD compact disc shipped with your unit They are also available through NG CEO technical service WARNING Make sure that the chiller will not contaminate the laser head Water Hoses and Filter Connections The required water hoses filters and fittings are included in the plumbing kit that was shipped with your laser They should be connected as illustrated in Figure 4 3 The corr
47. s completed inside the oscillator cavity the leftover fundamental simply returns to the oscillator and is conserved amplified and returned to the nonlinear frequency converter As a result nearly all the power which could have been optimally coupled out of the cavity by a semi transparent mirror is now converted to another wavelength provided that the semi transparent mirror is replaced by one that is fully reflective at the fundamental wavelength Ikiwa uses this intra cavity technique to double the laser frequency to a wavelength of 532 nm The frequency doubling device is a crystal of lithium triborate LBO cut at a special angle providing phase matching between the fundamental waves in the beam and the waves generated at 532 nm at around room temperature Phase matching and efficient conversion is sensitive to the angle to the unidirectional intra cavity beam and to the temperature of the LBO crystal As a result it is necessary to provide a stable mechanical and thermal environment for the doubling crystal A phase matching condition can be met by either the angular adjustment of the doubling crystal mechanically or by the varying the temperature of the crystal electrically Stability and reliability considerations lead to a mechanically fixed doubling crystal with fine tuning accomplished electrically With the doubling crystal mounted in a cell on the top of the thermal electric cooler TEC the temperature of the doubling crystal c
48. s must be equipped with the capability to utilize this feature When correctly used the interlock interrupts drive current to the diodes and Q switch when coolant flow rate drops below 1 GPM 3 7 LPM When setting up the laser system for the first time NG CEO highly recommends testing the flow interlock before firing By testing the interlock with no current to the laser there is no risk of damaging the laser WARNING Do not operate the coolant system below air condensation temperature dew point at the laser head Condensation on the diode arrays can seriously damage the laser head and will void the warranty Consult NG CEO technical service if you have any questions Air Condensation Temperature The air condensation temperature or dew point is the highest surface temperature that allows water to form from the ambient water vapor The dew point is dependent on the surrounding air temperature and relative humidity Ifa surface such as a laser diode is cooled at or below the condensation temperature water may collect on that surface A formula for calculating dew point is given below along with a calculated table All temperatures are given in Celsius Condensation Temperature d 237 7xa T RH 17 27xT ba In a T RH 17 27 a T RH where 237 7 T Lon T is the ambient air temperature in degrees Celsius 0 lt T lt 60 RH is the relative humidity in percent 1 lt RH lt 100 Ty is the air conden
49. s no improvement try the opposite direction Perform the same procedure with the vertical adjustments of the HM and HR mount Typically SHG temperature adjustment is not needed when adjusting vertically Periodically check for hold off when making these adjustments see in the Check Hold Off section in Chapter 5 Maintenance If laser power is within 5 percent of nominal typical power meter accuracy and it has good beam shape and stability stop and replace the access screws in the cover 40 Ikiwa Laser User Manual Chapter 6 Customer Service At Northrop Grumman Cutting Edge Optronics we are proud of the durability of our products Our manufacturing and guality control processes emphasize consistency ruggedness and high performance Nevertheless even the finest instruments break down occasionally We believe that the reliability record of our instruments compares favorably with that of our competition and we hope to demonstrate our superior service by providing dependable instruments and if the need arises service facilities that can restore your instrument to peak performance without delay When calling for service in the U S dial 636 916 4900 To phone for service in other countries contact your sales agent This chapter provides reference to types of customer service needs Contacting customer service Module replacement Return the instrument for repair Northrop Grumman Corporation 41 Ikiwa La
50. sation temperature Northrop Grumman Corporation 18 Ikiwa Laser User Manual Chapter 3 System Details For example suppose your chiller is running at 22 C and the ambient air temperature near the laser is 28 C 82 F Referring to Figure 3 4 and Table 3 4 find the intersection of the 28 C air temperature and the curve for the 22 C diode temperature At a relative humidity of 70 percent or greater condensation will form on the laser diodes Controlling the humidity level inside the laser is important to extend the lifetime of SHG crystal The desiccant cartridge on the top cover can help to removes excess moisture from inside the laser head WARNING Do not operate the laser without a functional desiccant cartridge Condensation on the diode arrays can seriously damage the laser and may void warranty Constant Dew Point Lines for Ambient Temperature and Relative Humidity 12 C 16 C 20 C 24 C 28 C 45 26 C Relative Humidity Oo a wo D ba Ei N N N a N co LA wo w lt j A Ei Temperature C Figure 3 9 Constant Dew Point Lines for Ambient Temperature and Relative Humidity Northrop Grumman Corporation 19 Ikiwa Laser User Manual Chapter 3 System Details Table 3 6 Table of Air Condensation Temperature at Given Ambient Air Temperature Celcius and Relative Humidity percent Relative Humidity 1 10 20 30 4
51. ser User Manual Chapter 6 Customer Service Contacting Customer Service To expedite your service needs please complete the questionnaire in Appendix A Customer Service before you contact NG CEO Technical Service Complete the questionnaire with as much detail as possible and retain a copy for your records E mail or fax the form to Cutting Edge Optronics refer to the second page of this manual for contact information and notify your techincal service representative that it has been sent Module Replacement Even though the pump module is user replaceable we recommend that the laser head be returned to NG CEO for an upgrade Contact NG CEO for detailed instructions about module replacement Return the Instrument for R epair A return merchandise authorization RMA is required prior to shipping any instruments to NG CEO Contact NG CEO or your local distributor for RMA and shipping instructions CAUTION Failure to obtain proper shipping instructions may result in damage to the instrument Use the packing boxes supplied by NG CEO to ship your instruments If shipping boxes have been lost or destroyed replacements are available for a nominal charge from NG CEO Northrop Grumman Corporation 42 Ikiwa Laser User Manual Chapter 6 Customer Service Remove all water from laser prior to packaging for shipment see Chapter 3 Maintenance for details Place a desiccant in a sealed ESD bag with the laser and secure the laser
52. technical service 0 Ca Ki 10 01 20 30 ORD 8813463 Figure 5 1 Desiccant Cartridge c ue 2 3 To replace an exhausted cartridge unscrew the old cartridge and screw in a new one Tighten with a quarter turn of a wrench to form a good seal The desiccant cartridge used in the Iklwa laser head is an industry standard part part number 680300 material 3506 with a 10 20 30 indicator Replacement cartridges may be purchased from Stid Chemie Performance Packaging 800 989 3374 www sud chemie com Northrop Grumman Corporation 34 Ikiwa Laser User Manual Chapter 5 Maintenance WARNING Do not operate the laser without a functional desiccant cartridge Condensation on the diode arrays or other optics can seriously damage the laser and may void warranty Maintain Chiller The 5 um filter and coolant in the chiller should be replaced a minimum of monthly Comply with your chiller manufacturer s recommendation if more frequent Drain and re fill the chiller per the chiller and coolant manufacturer s instructions Check Hold Off Checking hold off is a technique needed to verify proper operation of the laser To check hold off perform the following steps 1 2 J S O wo ND Northrop Grumman Corporation Turn on the laser and run for at least 20 minutes Lower the pump current to 10 A Set the Q Switch QSW to external trigger mode Ensure there is no input to the external gate
53. trip back to that location Oscillator beams are composed of transverse modes of simple structure related to a fundamental Gaussian intensity profile mode which is of the smallest lateral extent and divergence in the set The aperture in the oscillator path limits the laser beam s transverse spatial extent To achieve maximum power and efficiency this aperture should coincide with the aperture of the amplifier medium so that the oscillating beam fills the gain medium to the maximum extent Laser beam quality will degrade if the diameter of the fundamental mode is much smaller than the limiting aperture causing higher order modes to oscillate with a larger transverse extent and a higher divergence than the fundamental mode Beam quality is dependent upon the product of the diameter of the beam and its angular divergence as it propagates into the far distance This product is conserved with propagation and transformation by optical elements such as lenses and mirrors Beam quality can also be rated by the reduction of spot size achieved by simple focusing with higher quality beams providing spots with smaller diameters and higher intensities This factor also impacts the amount of achievable harmonic conversion and favors restricting laser operation to its fundamental Gaussian mode such as is used in the Iklwa laser The design of the laser cavity for fundamental mode operation involves the selection of cavity length and the characteristics of th
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