Chapter 5 Laser Heads - Agilent Technologies
Contents
1. 168 0mm 192 0 mm 6 61 7 56 o oJ 360 0 mm 14 17 CAUTION LASER LIGHT DO NOT STARE INTO BEAM MAXIMUM OUTPUT 1 mw PULSE SPEC continuous wave 44 0 helium neon ATE 0 173 CLASS I LASER PRODUCT WH 55 0 mm 2 17 Figure 5 12 Agilent 5519A B Laser Head dimensions User s Manual 5 33 Chapter 5 Laser Heads Laser Head Descriptions 5 34 Product specifications and descriptions in this document subject to change without notice Copyright C 2002 Agilent Technologies Printed in U S A 07 02 This is a chapter from the manual titled Laser and Optics User s Manual For complete manual order Paper version p n 05517 90045 CD version p n 05517 90063 This chapter is p n 05517 90105 User s Manual2. lt gt lt 139 6 mm 8 20 5 50 u MI a A 132 0 mm Ve 5 20 gt 17 7 mm i 19 3mm HU 0 76 0 76 3 2 nm 0 13 Dia gomm 34 6 mm 4 Places 0 35 43 4mm Dia 1 36 Dia Beam 1 71 325 2 61mm 70 1mm 101 6 mm gt gt lt gt 106 4 mm ere j 12 80 6 0 04 ai 128 3 mm ai w 128 3 mm 5 05 5 EE A a 598 i iz x e 4 10 7 mm gt 78 0 910 7 ma 027 347 9 mm 042 Beam 68 0 mm 13 70 79 5 mm 2 68 3 13 NOTE Laser Beam Exit Tolerances See Figure 3 16 form ounting Position 1 0 mm location detail gt lt 25 0mm 3X 0 039 3X M6 0 7 6 H THRU 0 98 Angle 3 0 m illiradians Hole for Alignment Pin gt x 12 5mm 3X See Note 0 49 Slot for Alignment Pin 7 12mm_ 3X See Note Ul 0 280 r 47 0 mm 1 85 Y 9 r y l E 4 012 025 6 0 705 mm par 0 16 0 24 8X R3 56mm 0mm i 0 140 1 85 CAUTION 100 0 ne esam 2 LASER LIGHT 7 09 DO NOT STARE INTO BEAM 189 0 mm 5 85 mm 2x E gt i MAXIMUM OUTPUT 1 mw 7 44 2 20 LASER MEDIUM helium noon 358 6 CLASS II LASER PRODUCT C 14 42 gt Figure 5 7B Agilent 5517C 009 Laser Head dimensions 5 22 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517D Laser Head Description The major structures of the Agilent 5517D Laser Head include the contro
3. Figure 5 7A Agilent 5517C Laser Head Standard and 5517C 003 dimensions User s Manual 5 21 Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517C 009 Laser Head Specifications PHYSICAL CHARACTERISTICS LASER BEAM CHARACTERISTICS Dimensions See figure below Type Helium Neon Continuous Two Frequency Weight 3 4 Kilograms 7 5 pounds Magnetic Field Strength Non Operating Maximum Beam Power Output 1 milliwatt Minimum Beam Power Output 180 microwatts Does not exceed 5 25 milligauss at a distance of 460 cm 15 ft Beam Diameter 9 millimeters typical from any point on the surface of the packaged Laser Head Vacuum Wavelength Accuracy 3 sigma lifetime 0 1 ppm Clearance Required for Cabling 10 16 cm 4 in beyond back POWER Power Input Requirements Vacuum Wavelength Stability typical 1 hour 0 002 ppm Vacuum Wavelength Stability typical lifetime 0 02 ppm Nominal Vacuum Wavelength 632 991354 nanometers 15 Volts 0 3 Volts at 2 2 Amperes maximum 15 Volts 0 3 Volts at 0 02 Ampere maximum Safety Classification Class II Laser Product conforming to U S Heat Dissipation 23 watts during operation 35 watts during National Center for Devices and Radiological warmup Health Regulations 21 CFR 1040 10 and 1040 11 OUTPUTS Reference Frequency 2 4 3 0 MHz Warmup Time less than 10 minutes 4 minutes typical 208 3 mm
4. of this manual In addition the Agilent 5519A B has a two position turret ring to configure the head for straightness measurements requires Agilent 10774A or Agilent 10775A straightness optics in one position and all other measurements in the other The Agilent 5519A B has three rear panel LED indicators and two front panel LED indicators The LASER ON indicator alerts the operator when the 5519A B Laser Head is activated and emitting a laser beam Electrically this indicator monitors the 15 Volt line on the low voltage power supply output This indicator is on both the front and rear panels of the 5519A B The SIGNAL indicator shows when a sufficient laser beam measurement signal is returned to the measurement receiver assembly within the 5519A B Laser Head This indcator is on both the front and rear panels of the 5519A B The rear panel READY indicator is extinguished when the 5519A B Laser Head is in the warm up mode It flashes on and off when the 5519A B Laser Head begins the optical mode and is steady when the 5519A B Laser Head is ready for use 5 28 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Functional Description As shown in Figure 5 11 the high voltage power supply receives 15 V from the low voltage power supply through A1F 1 The laser head emits a collimated dual frequency laser beam with a high degree of stability A portion of the emitted beam is directed to an internal sampler assem
5. 6 mm Standard 3 mm Opt 003 9 mm Opt 009 Same as Agilent 5517B C 3 4 to 4 0 6mm Large 2 4 to 3 0 6mm User s Manual Large 3 4 to 4 0 6mm 5 9 Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517A Laser Head Description The major structures of the Agilent 5517A Laser Head include the control electronics the laser tube assembly the sampler assembly the reference receiver and the high voltage power supply All of the necessary control signals for the operation of the Agilent 5517A are generated internally Power requirements are and 15 Volts Refer to the Agilent 5517A Specifications section for more information on power requirements The Agilent 5517A Laser Head shown in Figure 5 2 is supplied with three Mounting Screws M8 x1 2 x25 mm Agilent Part Number 0515 0798 Cables available as accessories are listed in Chapter 9 Accessories of this manual The three position shutter on the Agilent 5517A can be set for open reduced or closed apertures The Agilent 5517A has two rear panel LED indicators The LASER ON LED alerts the operator that the laser head is activated and is emitting a laser beam About halfway through the warm up period the READY LED blinks on and off to indicate that the laser is in the process of warming up When the laser head is ready for use the READY LED remains on Any necessary retuning is performed automatically and
6. I ss uluBiens pinbry JOMOd dn uue A I gt PIOH pue ajdwes AA I ASL mes dw l Bunoenqns I ou J u gt sopd I j 10113 I AA Sel s aunyeseduia poy dn uuey g gt gt I MOULH I ld 6 I Ju uoduioo ulbu 1 e H I IPOIN A J Y I a sondo oy lt 0 lt lt AWARD LY uoeds _ l l a m p B I s87 Jose lt ee 4ayeaH cd I ju uoduloo I IgluozuoH sondo s do Ajqw ssy 1jdwes Ajquiassy 1 se1 318vsiq PSAo ee Soluono la Ionuo2 S V6LSS 1u llV pe H sese7 peaysese7 a V6LSS l a V6LSS apisino p sul Figure 5 11 Agilent 5519A B Laser Head Block Diagram 5 31 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Mounting and Clearance The Agilent 5519A B Laser Head has three mounting feet with tapped holes M8 X 1 25 that go completely through the feet and allow mounting on a mounting plate or bulkhead F or measurement axis alignment purposes slotted through holes should be provided in the mounting surface Aluminum is the preferred material for any mounting surface since this will match the thermal coefficient of expansion of the laser base If aluminum cannot be used kinematic mounting of the rear mounting foot is recommended to minimize stresses due to temperature changes In addition Allow 50 mm 2 inches clearance around the laser head for easy servicing Allow at least 125 mm 5 inches clearance at the back of the laser head for cable connections Tomaintain goo
7. LASER ON READY 5517C 2 4 MHz to 6 mm std f4 Horiz 15V POWERON Open reduced 3 0 MHz 3 mm 5517C 003 f gt Vert 15V POWERON closed 9 mm 5517C 009 LASER ON READY 5 2 User s Manual Chapter 5 Laser Heads Frequencies and Polarizations Table 5 1 Laser Heads Summary Continued Reference Requency 3 4 MHz to 4 0 MHz Agilent Model Beam Diameter Polarization f4 Horiz fo Vert Indicators 15V POWER ON 15V POWER ON LASER ON READY Shutter Open reduced closed f4 Horiz fo Vert LASER ON SIGNAL READY Turret ring configures for straightness or other measurement 5519B 3 4 to 4 0 MHz Same as 5519A Same as Same as 5519A Same as 5519A 5519A F is the lower frequency and fo is the higher frequency The Agilent 5517A is the basic laser head The Agilent 5517B Agilent 5517C and Agilent 5517D are smaller packages than the Agilent 5517A The Agilent 5517B Agilent 5517C and Agilent 5517D have higher reference frequencies than the Agilent 5517A The higher frequencies allow higher axis velocity capability depending on the electronics used The Agilent 5519A and Agilent 5519B are designed to be used as a part of the Agilent 5529A Dynamic Calibrator system The Agilent 5519B has a higher frequency that the Agilent 5519A The higher frequency allows higher axis velocity capability Frequencies and Polarizations Agilent laser heads pro
8. Vacuum Wavelength Stability typical lifetime 0 02 ppm Power Input Requirements Nominal Vacuum Wavelength 632 99137 nanometers 15 Volts 0 3 Volts at 2 5 Amperes maximum Safety Classification 15 Volts 0 3 Volts at 0 02 Ampere maximum Class II Laser Product conforming to U S Heat Dissipation 23 watts during operation National Center for Devices and Radiological 35 watts during warmup Health Regulations 21 CFR 1040 10 and 1040 11 Warmup Time less than 10 minutes 4 minutes typical OUTPUTS Reference Frequency 1 5 2 0 MHz 83 8 mm M8x1 25 Thread 3 30 3 Places 167 5 mm 142 0 mm 6 59 5 59 o Y No Z 13 0mm 360 0 mm __ _ 0 51 14 17 le 458 0 mm 18 03 479 0 mm 18 85 l gt 83 8 mm 120 mm min clear 3 30 4 72 ae a she 435 0mm 118 0 mm ae ie 17 13 7 4 65 P a Sn 83 0 mm K A 3 27 m ET Y Y Y 1920mm_ _ 22 3 mm Dia Al L 7 56 118 0mm 55 1 mm 49 5 mm 0 88 4 65 2 17 1 95 Des CAUTION This is a Class II Laser Product con LASER LIGHT forming to Federal Bureau of Radio logical Health Regulations 21 CFR ope eee 1040 10 and 1040 11 MAXIMUM OUTPUT 1 mw PULSE SPEC continuous wave LASER MEDIUM helium neon CLASS II LASER PRODUCT Figure 5 3 Agilent 5517A Laser Head dimensions User s Manual 5 13 Chapte
9. ae 34 6 mm L E D 1 36 4 Places Dia Beam ary mm Dia 70 1mm 101 6 mm 4 106 4 mm 2 76 4 0 619 19 rf AANS 128 3 mm A 128 3 mm 5 05 Q 5 05 it y oo yoy Beam 11 43 mm i a mm 40 7 e 78 6 mm 0 45 0 26 LIL re 5 1 0 mm 3 10 045 0 26 0 42 oa 3 13 0 04 n il w A gt CAUTION I i iw 17 78mm_ Typ gt eae BEAM 0 70 MAXIMUM OUTPUT 1 mw 170 2 mm EA PULSE SPEC continuous wave 6 70 a 358 6 mm lt 442 Figure 5 9 Agilent 5517D Laser Head dimensions 5 26 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Agilent 5519A B Laser Head and Receiver Description The Agilent 5519A B Laser Head shown in Figure 5 10 which is a component of the Agilent 5529A 55292A Dynamic Calibrator system incorporates a helium neon laser with a beam diameter of 6 mm 20 24 in It has a wavelength accuracy of 0 1 ppm 40 02 ppm if calibrated The Agilent 5519A B uses Agilent s two frequency laser technique that virtually eliminates the problems common to other laser designs which result from beam intensity changes The laser head uses a proven long life tube LASER on OSI AT URE SIGNAL AVOID Ex EMME tE RADIAT OM This ON IS e OTHER ERATURE Pi HI Agilent 5519A B Laser Head and Receiver Figure 5 10 Agilent 5519A B Laser Head The Agilent 5519A and Agilent 5519B differs only in their reference frequency output The Agil
10. mounting arrangement requires a specially prepared mounting site for the laser head see Figure 3 16 For measurement axis alignment purposes slotted through holes should be provided in the mounting surface Aluminum is the preferred material for any mounting surface since this will match the thermal coefficient of expansion of the laser base If aluminum cannot be used kinematic mounting of the rear mounting foot is recommended to minimize stresses due to temperature changes In addition Allow 50 mm 2 inches clearance around the laser head for easy servicing Allow at least 100 mm 4 inches clearance at the back of the laser head for cable connections Tomaintain good pointing stability it is good practice to use kinematic mounting principles User s Manual 5 19 Chapter 5 Laser Heads Laser Head Descriptions LASER LIGHT EMISSION FROM THIS APERTURE AVOID EXPOSURE gt i Agilent 5517C Laser Head Figure 5 6 Agilent 5517C Laser Head The laser head emits a laser beam containing a vertically polarized component f the higher of the two optical frequencies and a horizontally polarized component f A portion of the emitted beam is directed to the sampler assembly Most of this sample feeds into the reference receiver and the remainder of the sample is used to control laser tuning The reference receiver generates the reference frequency signal by mixing the two laser frequencies The reference frequen
11. Agilent 5517C has a 6 mm diameter laser beam The Agilent 5517C 003 has a 3 mm beam The Agilent 5517C 009 has a 9 mm beam The three position shutter on the Agilent 5517C can be set for open reduced or closed apertures The Agilent 5517C has four rear panel indicators The 15V POWER ON and 15V POWER ON LEDs indicate that power has been applied and that the respective fuses are intact The LASER ON LED alerts the operator that the laser head is activated and is emitting a laser beam About halfway through the warm up period the READY LED blinks on and off to indicate that the laser is in the process of warming up When the head is ready for use the READY LED remains on Any necessary retuning is performed automatically and is indicated by the READY LED flashing 5 18 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Mounting and Clearance The standard or 5517C 003 Laser Head can be fastened down using the mounting feet or six tapped holes on the base of the head The mounting feet have clearance slots for 1 4 20 or M6 screws Alternatively the mounting feet can be removed and the head fastened using the 8 32 UNC tapped holes under the base The Agilent 5517C 009 Laser H ead offers a choice of mounting arrangements It can be mounted like a standard Agilent 5517C or Agilent 5517C 003 Laser Head or You can take advantage of the fact that its output beam is referenced to locations on its base This
12. Axes The output from a single laser head can be used for measurements involving many axes of motion plus the wavelength tracking compensation axis The number of axes that can be measured depends on the optical power available from the laser head and the optics and system measurement electronics being used Measurement Range Nominal optical measurement range for the system is 40 meters 130 feet for the sum of all axes when using a laser head with a standard 6 mm beam Heat Generation There is some heat dissipation from the laser heads Where possible install the laser head far enough away from the measurement area to avoid any thermal effects On a small or very accurate machine choose the mounting method and location with care 5 4 User s Manual Chapter 5 Laser Heads Accuracy Considerations Accuracy Considerations The wavelength of light from the laser head serves as the length standard for Agilent laser measurement systems Since the laser transition of the neon atom provides a fundamental physical reference the Agilent interferometric system is considered a primary standard for metrology The standard long term wavelength accuracy in a vacuum of Agilent laser heads is 0 1 part per million 1 x107 or 0 1 micron per meter 0 1 microinch per inch It is customary to specify laser accuracy in vacuum because the variable characteristics of air Such as temperature humidity pressure and gas mixture havea
13. DY LED blinks on and off to indicate that the laser is in the process of warming up When the head is ready for use the READY LED remains on Any necessary retuning is performed automatically and is indicated by the READY LED flashing Mounting and Clearance The Agilent 5517B Laser Head can be fastened down using the mounting feet or six tapped holes on the base of the head The mounting feet have clearance slots for 1 4 20 or M6 screws Alternatively the mounting feet can be removed and the head fastened using the 8 32 UNC tapped holes under the base 5 14 User s Manual Chapter 5 Laser Heads Laser Head Descriptions For measurement axis alignment purposes slotted through holes should be provided in the mounting surface Aluminum is the preferred material for any mounting surface since this will match the thermal coefficient of expansion of the laser base If aluminum cannot be used kinematic mounting of the rear mounting foot is recommended to minimize stresses due to temperature changes In addition Allow 50 mm 2 inches clearance around the laser head for easy servicing Allow at least 100 mm 4 inches clearance at the back of the laser head for cable connections Tomaintain good pointing stability it is good practice to use kinematic mounting principles LASER LIGHT EMISSION FROM THIS APERTURE AVOID EXPOSURE Agilent 5517B Laser Head Figure 5 4 Agilent 5517B Laser Head The laser head emi
14. Laser Heads Chapter 5 Laser Heads General General One laser head is required in most measurement systems regardless of the number of measurement axes in the system The wavelength of light from the laser head is used as the length standard for Agilent laser measurement systems The laser head generates a coherent all light waves in phase collimated all waves traveling parallel to one another light beam consisting of two orthogonally polarized frequency components To differentiate between the frequencies the lower frequency is identified as fz and the higher as fz The difference between these two frequencies is the Reference Frequency listed in Table 5 1 Agilent offers several laser head models to fill a variety of requirements A summary listing of Agilent laser heads is provided in Table 5 1 In addition to system information for the laser heads complete descriptions equipment supplied information and specifications for each laser heads are given in this chapter Each of these laser heads requires a cable to connect it to the measurement system electronics Cables are listed in Chapter 9 Accessories of this manual Table 5 1 Laser Heads Summary Reference Beam Requency Diameter Polarization Indicators Shutter 5517A 1 5 MHz to 6mm f Horiz LASER ON Open reduced 2 0 MHz fo Vert READY closed 5517B 1 9 MHz to 6mm f4 Horiz 15V POWER ON Open reduced 2 4 MHz fo Vert 15V POWER ON closed
15. bly to establish the reference frequency the main portion of the beam is directed to external optics and returned to an internal measurement receiver to develop the measurement frequency The system electronics compare the reference and measurement frequencies to calculate the displacement of the optics The control electronics determine the tuning of the laser assembly to ensure an accurate laser wavelength for making measurements Two phases of tuning are used warm up mode and optical mode When the desired characteristics of the laser beam are obtained during the optical mode the system is ready to make measurements When properly tuned the laser outputs two laser frequencies Laser frequency f the lower frequency is polarized in a plane parallel tothe bottom of the 5519A B chassis The higher laser frequency f gt is polarized perpendicular to fz The difference between the two laser frequencies called the split frequency is 2 4 to 3 0 MHz for 5519A and 3 4 to 4 0 MHz for 5519B The split frequency is small compared to the optical frequencies about 1014 Hz The laser assembly optics ensure correct laser frequency polarizations and also collimate the laser beam Collimating the beam minimizes variations in the diameter of the beam as it travels away from the laser head Before the laser light is emitted from the 5519A B Laser Head a portion of it is sampled by the sampler assembly Most of this sample feeds into the reference rec
16. ctice to use kinematic mounting principles 5 24 User s Manual Chapter 5 Laser Heads Laser Head Descriptions LASER LIGHT EMISSION FROM THIS APERTURE AVOID EXPOSURE Agilent 5517D Laser Head Figure 5 8 Agilent 5517D Laser Head The laser head emits a laser beam containing a vertically polarized component f gt the higher of the two optical frequencies and a beam is horizontally polarized component f A portion of the emitted directed to the sampler assembly M ost of this sample feeds into the reference receiver and the remainder of the sample is used to control laser tuning Thereference receiver generates the reference frequency signal by mixing the two laser frequencies The reference frequency is in the range of 3 4 to 4 0 MHz and is a TTL level square wave The higher the reference frequency the higher the slew rate at which the measurement optic can move When the laser tuning stabilizes the reference frequency is sent to the system electronics The main portion of the beam is directed by system optics to an external receiver where a measurement signal is generated The measurement and reference signals are compared by the Agilent laser system electronics to generate a displacement measurement signal User s Manual 5 25 Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517D Laser Head Specifications PHYSICAL CHARACTERISTICS LASER BEAM CHARACTERISTICS Dimensions See figure below Type Helium Ne
17. cy is in the range of 2 4 to 3 0 MHz and is a TTL level square wave The higher the reference frequency the higher the slew rate at which the measurement optic can move When the laser tuning stabilizes the reference frequency is sent to the system electronics The main portion of the beam is directed by system optics to an external receiver where a measurement signal is generated The measurement and reference signals are compared by the Agilent laser system electronics to generate a displacement measurement signal 5 20 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517C Laser Head Specifications Standard and 5517C 003 PHYSICAL CHARACTERISTICS Dimensions See figure below Weight 3 4 Kilograms 7 5 pounds Magnetic Field Strength Non Operating Does not exceed 5 25 milligauss at a distance of 460 cm 15 ft from any point on the surface of the packaged Laser Head Clearance Required for Cabling 10 16 cm 4 in beyond back POWER Power Input Requirements 15 Volts 0 3 Volts at 2 2 Amperes maximum 15 Volts 0 3 Volts at 0 02 Ampere maximum Heat Dissipation 23 watts during operation 35 watts during warmup Warmup Time less than 10 minutes 4 minutes typical LASER BEAM CHARACTERISTICS Type Helium Neon Continuous Two Frequency Maximum Beam Power Output 1 milliwatt Minimum Beam Power Output 180 microwatts Beam Diameter 6 millimeters 0 25 inch typical Standard 3 millime
18. d pointing stability it is good practice to use kinematic mounting principles 5 32 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Agilent 5519A B Laser Head Specifications PHYSICAL CHARACTERISTICS LASER BEAM CHARACTERISTICS Dimensions See figure below Type Helium Neon Continuous Two Frequency Weight 5 8 Kilograms 12 5 pounds Maximum Beam Power Output 1 milliwatt Magnetic Field Strength Non Operating Minimum Beam Power Output 180 microwatts Does not exceed 5 25 milligauss at a distance of 460 cm 15 ft Beam Diameter 6 millimeters 0 24 inch typical from any point on the surface of the packaged Laser Head Vacuum Wavelength Accuracy 3 sigma lifetime 0 1 ppm Clearance Required for Cabling 10 cm 4 in beyond back Vacuum Wavelength Stability typical 1 hour 0 002 ppm POWER Vacuum Wavelength Stability typical lifetime 0 02 ppm Power Input Requirements Nominal Vacuum Wavelength 632 991354 nanometers 100 to 120 Vac 48 to 66 Hz or 400 Hz or Safety Classification 220 to 240 Vac 48 to 66 Hz from external system power supplies Class II Laser Product conforming to U S Heat Dissipation 33 watts during operation National Center for Devices and Radiological 50 watts during warmup Health Regulations 21 CFR 1040 10 and 1040 11 Warmup Time less than 10 minutes 4 minutes typical OUTPUTS Reference Frequency 2 4 3 0 MHz for Agilent 5519A 3 4 to 4 0 MHz for Agilent 5519B M8 x 1 25 Thread v4 3 Places
19. duce a coherent collimated two frequency laser beam consisting of two orthogonally polarized frequency components Frequencies f4 the lower frequency and fp are always orthogonally polarized with respect to one another However either may be vertically or horizontally polarized Agilent laser heads have f horizontally polarized Polarization affects the direction sense F or example if e f4 the lower frequency is in the measurement path fisin the reference path and the optics are moving away from each other the fringe counts will be increasing Interchanging f and fz in this example will cause the fringe counts to decrease User s Manual 5 3 Chapter 5 Laser Heads Number of Measurement Axes Before the laser beam leaves the laser head part of it is sampled to determine the difference frequency between its two optical components This difference frequency is called the Reference Frequency or Split Frequency The beam leaving the laser head is directed through a configuration of beam directing optics and measurement optics and then to a receiver The receiver provides a Measurement Frequency which when compared to the Reference Frequency from the laser head yields displacement information If a measurement axis is used for wavelength tracking instead of a displacement measurement its Measurement Frequency yields wavelength of light information instead of displacement information Number of Measurement
20. e READY LED blinks on and off to indicate that the laser is in the process of warming up When the head is ready for use the READY LED remains on Any necessary retuning is performed automatically and is indicated by the READY LED flashing User s Manual 5 23 Chapter 5 Laser Heads Laser Head Descriptions Mounting and Clearance The 5517D Laser Head can be fastened down using the mounting feet or six tapped holes on the base of the head The mounting feet have clearance slots for 1 4 0 or M6 screws Alternatively the mounting feet can be removed and the head fastened using the 8 32 UNC tapped holes under the base You can take advantage of the fact that its output beam is referenced to locations on its base This mounting arrangement requires a specially prepared mounting site for the laser head see Figure 3 16 For measurement axis alignment purposes slotted through holes should be provided in the mounting surface Aluminum is the preferred material for any mounting surface since this will match the thermal coefficient of expansion of the laser base If aluminum cannot be used kinematic mounting of the rear mounting foot is recommended to minimize stresses due to temperature changes In addition Allow 50 mm 2 inches clearance around the laser head for easy servicing Allow at least 100 mm 4 inches clearance at the back of the laser head for cable connections Tomaintain good pointing stability it is good pra
21. eiver the remainder of the sample is used to control laser tuning The reference receiver generates the reference frequency signal by mixing the two laser frequencies The reference frequency is the difference between the two laser frequencies also known as the split frequency The reference frequency is in the range of 2 4 to 3 0 MHz for 5519A or 3 4 to 4 0 MHz for 5519B andisaTTL level square wave When the laser tuning stabilizes the reference frequency is sent to the system electronics The turret assembly includes the straightness mount When the straightness mount is set to OTHER it places nothing in the exit or return aperture When the straightness mount is set to STRAIGHT the laser beam passes through a beam splitter that transmits only 30 User s Manual 5 29 Chapter 5 Laser Heads Laser Head Descriptions of the beam The return beam is coaxial with the exit beam and is reflected off the front surface of the beam splitter to a mirror which reflects the beam into the receiver In STRAIGHT a switch is closed which increases receiver gain to compensate for losses in the mount The exit aperture shutter of the turret assembly has three positions The first blocks the laser beam entirely the second allows a small diameter laser beam to exit for optical alignment purposes and the third passes the entire laser beam for normal operation During a measurement the laser beam follows a path through external measurement optics and
22. en stable once the laser head has reached thermal equilibrium typically about 30 minutes This alignment change during warm up of the laser head is less than 2 arc minutes typically 1 arc minute for the 6 mm beam When aligning the laser optics or receiver be sure the laser head has been powered on until the READY LED is on not flashing This will assure proper alignment for subsequent power ups LASER POSITION TRANSDUCER MOUNTING Beam Bender Figure 5 1 Laser position Transducer mounting The laser heads should not be exposed to ambient temperature change greater than 45 C during operation to keep pointing stability variations to within a few arc seconds during measurements 5 8 User s Manual Chapter 5 Laser Heads Maintenance Requirements Maintenance Requirements Refer to Chapter 10 Maintenance in this manual for this information Laser Head Descriptions Comparison of Laser Heads The differences between the Agilent 5517A Agilent 5517B Agilent 5517C Agilent 5517D Agilent 5519A and Agilent 5519B laser heads and options are package size reference frequency and beam diameter summarized in Table 5 2 below Table 5 2 Comparison of Agilent 5517A B C D Laser Heads Summary Agilent Model Package Size Large Reference Frequency MHz 1 5 to 2 0 Beam Diameter nominal 6mm Same as Agilent 5517C 1 9 to 2 4 mm 6mm Same as Agilent 5517B 2 4 to 3 0
23. endicular to beam axis at an interferometer or receiver the beam signal power can fluctuate If this fluctuation is too great insufficient beam signal will arrive at the receiver causing a measurement signal error Automatic Tuning and Warmup Period To maintain a stable frequency output Agilent laser heads have thermally stabilized cavity lengths controlled by automatic tuning circuitry Thermal stabilization requires a warmup period The typical warmup period is four minutes The maximum warmup period is ten minutes Beam Shutters To facilitate alignment and meet safety standards the laser heads have shutter controls installed at the laser beam exit aperture The beam may be blocked entirely for safety reduced for alignment or unimpeded for normal operation The Agilent 5517A Agilent 5517B Agilent 5517C Agilent 5517D and Agilent 5519A B laser heads have different shutter arrangements The shutter arrangements for each laser head is described in the Laser Head Descriptions section in this chapter 5 6 User s Manual Chapter 5 Laser Heads Orientation Orientation An Agilent laser head may be mounted in any orientation as long as its beam enters the optical system parallel to or orthogonal with the machine axes being measured When mounting the laser head vertically with the beam directed upward be careful not to mount an interferometer directly above it because of heat dissipation from the laser head t
24. ent 5519A reference frequency output is 2 4 MHzto 3 0 MHz The Agilent 5519B reference frequency output is 3 4 MHz to 4 0 MHz The higher the reference frequency the higher the slew rate at which the measurement optic can move The Agilent 5519A B is configured with appropriate optics and system electronics to build a laser calibration system that meets the unique phyiscal layout and measurement requirements of individual applications The laser accuracy is ideal for machine calibration applications User s Manual 5 27 Chapter 5 Laser Heads Laser Head Descriptions The major structures of the Agilent 5519A B are the control electronics the laser tube assembly the sampler assembly the reference receiver the measurement receiver the turret optics and the high voltage power supply All of the necessary control signals for the operation of the 5519A B Laser Head are generated internally Power requirements are 100 to 120 Vac 48 to 66 Hz or 400 Hz or 220 to 240 Vac 48 to 66 Hz from external system power supplies See Figure 5 11 for a block diagram that shows how input power is applied to the 5519A B Laser Head The 5519A B Laser Head shown in Figure 5 10 is supplied with two Mounting Screws M8 X 1 25 X 25 mm Agilent Part Number 0515 0798 aLeveling Foot and Locking Nut Agilent Part Numbers 05518 20316 and 05518 20317 respectively Cables available as accessories are listed in Chapter 9 Accessories
25. hat may reduce measurement accuracy The plane defined by the three mounting feet on the laser head must be parallel to either the bottom or sides of the beam splitters and beam bender housings to within 38 and to the bottom or sides of the interferometers to within 1 This ensures that the polarization axes of the interferometers are oriented properly relative to the polarization vectors of the laser beam Figure 5 1 The laser head can be rotated in 90 increments about the beam axis roll without affecting the system performance but the measurement direction sense will change with each 90 rotation Although the laser head or the receiver may be rotated in 90 increments about the beam axis roll other roll deviations from the four optimum positions degrade the measurement signal If either the laser head or receiver is rotated 45 about the beam axis all position information will be lost because the receiver will not be able to distinguish between the two frequencies Magnetic Shielding Agilent laser heads contain a permanent magnet When installing an Agilent laser measurement system in an application sensitive to magnetic fields shielding around the laser head may be required User s Manual 5 7 Chapter 5 Laser Heads Pointing Stability Pointing Stability The alignment of the laser beam with respect to the mounting feet pointing stability changes slightly during warm up of the laser head Beam alignment is th
26. is indicated by the READY LED flashing 5 10 User s Manual Chapter 5 Laser Heads Laser Head Descriptions AVOID LASER RPO EMITTER FROM ATION APERA TURE Agilent 5517A Laser Head Figure 5 2 Agilent 5517A Laser Head Mounting and Clearance The Agilent 5517A Laser Head has three mounting feet with tapped holes M8 x 1 25 that go completely through the feet and allow mounting on a mounting plate or bulkhead F or measurement axis alignment purposes slotted through holes should be provided in the mounting surface Aluminum is the preferred material for any mounting surface since this will match the thermal coefficient of expansion of the laser base If aluminum cannot be used kinematic mounting of the rear mounting foot is recommended to minimize stresses due to temperature changes In addition Allow 50 mm 2 inches clearance around the laser head for easy servicing Allow at least 125 mm 5 inches clearance at the back of the laser head for cable connections Tomaintain good pointing stability it is good practice to use kinematic mounting principles User s Manual 5 11 Chapter 5 Laser Heads Laser Head Descriptions The laser head emits a laser beam containing a vertically polarized component f gt the higher of the two optical frequencies and a horizontally polarized component f A portion of the emitted beam is directed to the sampler assembly Most of this sample feeds into the refere
27. l electronics the laser tube assembly the sampler assembly the reference receiver and the high voltage power supply All of the necessary control signals for the operation of the Agilent 5517D are generated internally Power requirements are and 15 Volts Refer to the Agilent 5517D Specifications section for more information on power requirements The Agilent 5517D is similar tothe Agilent 5517C Agilent 5517B and Agilent 5517A with respect to laser beam polarizations and current requirements The Agilent 5517D has a higher reference frequency 3 4 to 4 0 MHz than the Agilent 5517C Agilent 5517B or Agilent 5517A allowing faster measurement velocities slew rates The Agilent 5517D package is the same as that of the Agilent 5517B and Agilent 5517C The Agilent 5517D Laser Head shown in Figure 5 8 is supplied with a Test Polarizer Agilent Part Number 1000 0616 Cables available as accessories are listed in Chapter 9 Accessories of this manual The Agilent 5517D has a 6 mm diameter laser beam The three position shutter on the Agilent 5517D can be set for open reduced or closed apertures The Agilent 5517D has four rear panel indicators The 15V POWER ON and 15V POWER ON LEDs indicate that power has been applied and that the respective fuses are intact The LASER ON LED alerts the operator that the laser head is activated and is emitting a laser beam About halfway through the warm up period th
28. m 128 3 mm 3 5 05 D 5 05 I t Beam 11 43 mm 78 6 mm lt 0 45 O28 79 5 1 0mm 3 10 3 13 0 04 ni 2 WI 01 SOT HHARE Mo BEAM 0 70 MAXIMUM OUTPUT 1 mw 170 18 mm TASER MEDIUM helium neon 6 70 CLASS II LASER PRODUCT 358 6 mm s 14 12 gt Figure 5 5 Agilent 5517B Laser Head dimensions User s Manual 5 17 Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517C Laser Head Description The major structures of the Agilent 5517C Laser Head include the control electronics the laser tube assembly the sampler assembly the reference receiver and the high voltage power supply All of the necessary control signals for the operation of the Agilent 5517C are generated internally Power requirements are and 15 Volts Refer to the Agilent 5517C Specifications section for more information on power requirements The Agilent 5517C is similar to the Agilent 5517B and Agilent 5517A with respect to laser beam polarizations and current requirements The Agilent 5517C has a higher reference frequency than the Agilent 5517A or Agilent 5517B allowing faster measurement velocities slew rates The Agilent 5517C package is the same as that of the Agilent 5517B The Agilent 5517C Laser Head shown in Figure 5 6 is supplied with a Test Polarizer Agilent Part Number 1000 0616 Cables available as accessories are listed in Chapter 9 Accessories of this manual The standard
29. m 4 in beyond back POWER Power Input Requirements 15 Volts 0 3 Volts at 2 2 Amperes maximum 15 Volts 0 3 Volts at 0 02 Ampere maximum Heat Dissipation 23 watts during operation 35 watts during warmup Warmup Time less than 10 minutes 4 minutes typical LASER BEAM CHARACTERISTICS Type Helium Neon Continuous Two Frequency Maximum Beam Power Output 1 milliwatt Minimum Beam Power Output 120 microwatts Beam Diameter 6 millimeters 0 25 inch typical Vacuum Wavelength Accuracy 3 sigma lifetime 0 1 ppm Vacuum Wavelength Stability typical 1 hour 0 002 ppm Vacuum Wavelength Stability typical lifetime 0 02 ppm Nominal Vacuum Wavelength 632 99137 nanometers Safety Classification Class II Laser Product conforming to U S National Center for Devices and Radiological Health Regulations 21 CFR 1040 10 and 1040 11 OUTPUTS Reference Frequency 1 9 2 4 MHz 13 7 mm 25 4 mm Max p 0 54 1 00 Y __ Full Radius l h 208 3 mm 139 6 mm 8 20 5 50 7 11 mm Detail gt Y 0 28 3 Places 132 0 mm j 5 20 gt 17 7 mm L 7 19 3 mm 0 70 UM 0 76 3 2 mm 0 13 Dia 6 0 mm 34 6 mm L E D 0 24 1 36 4 Places Dia Beam an Dia 325 2 1mm 70 1 mm 101 6 mm 12 4 1106 4 mm 2 76 4 0 12 00 0 03 4 19 At 128 3 m
30. nce receiver and the remainder of the sample is used to control laser tuning The reference receiver generates the reference frequency signal by mixing the two laser frequencies The reference frequency is in the range of 1 5 to 2 0 MHz and is a TTL level square wave The higher the reference frequency the higher the slew rate at which the measurement optic can move When the laser tuning stabilizes the reference frequency is sent to the system electronics The main portion of the beam is directed by system optics to an external receiver where a measurement signal is generated The measurement and reference signals are compared by the Agilent laser system electronics to generate a displacement measurement signal 5 12 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517A Laser Head Specification PHYSICAL CHARACTERISTICS LASER BEAM CHARACTERISTICS Dimensions See figure below Type Helium Neon Continuous Two Frequency Weight 5 5 Kilograms 12 pounds Maximum Beam Power Output 1 milliwatt Magnetic Field Strength Non Operating Minimum Beam Power Output 180 microwatts Does not exceed 5 25 milligauss at a distance of 460 cm 15 ft Beam Diameter 6 millimeters 0 25 inch typical from any point on the surface of the packaged Laser Head Vacuum Wavelength Accuracy 3 sigma lifetime 0 1 ppm Clearance Required for Cabling 12 00 cm 4 72 in beyond back Vacuum Wavelength Stability typical 1 hour 0 002 ppm POWER
31. on Continuous Two Frequency Weight 3 4 Kilograms 7 5 pounds Maximum Beam Power Output 1 milliwatt Magnetic Field Strength Non Operating Minimum Beam Power Output 180 microwatts Does not exceed 5 25 milligauss at a distance of 460 cm 15 ft Beam Diameter 6 millimeters 0 25 inch typical from any point on the surface of the packaged Laser Head Vacuum Wavelength Accuracy 3 sigma lifetime 0 1 ppm Clearance Required for Cabling 10 16 cm 4 in beyond back Vacuum Wavelength Stability typical 1 hour 0 002 ppm POWER Vacuum Wavelength Stability typical lifetime 0 02 ppm Power Input Requirements Nominal Vacuum Wavelength 632 991354 nanometers 15 Volts 0 3 Volts at 2 2 Amperes maximum Safety Classification 15 Volts 0 3 Volts at 0 02 Ampere maximum Class II Laser Product conforming to U S Heat Dissipation 23 watts during operation National Center for Devices and Radiological 35 watts during warmup Health Regulations 21 CFR 1040 10 and 1040 11 Warmup Time less than 10 minutes 4 minutes typical OUTPUTS Reference Frequency 3 4 4 0 MHz 0 54 _ Full Radius 25 4mm Max 1 00 a lt 13 7 mm 208 3mm st 139 6 mm 8 20 5 50 7 44 mm Detail M I 0 28 3 Places 132 0 mm m 5 20 lt 17 7 mm MW 19 3 mm 0 70 0 76 3 2mm 0 13 Dia
32. r 5 Laser Heads Laser Head Descriptions Agilent 5517B Laser Head Description The major structures of the Agilent 5517B Laser Head include the control electronics the laser tube assembly the sampler assembly the reference receiver and the high voltage power supply All of the necessary control signals for the operation of the Agilent 5517B are generated internally Power requirements are and 15 Volts Refer to the Agilent 5517B Specifications section for more information on power requirements The Agilent 5517B is similar tothe Agilent 5517A with respect to laser beam polarizations and current requirements The Agilent 5517B has a higher reference frequency than the Agilent 5517A allowing faster measurement velocities slew rates The Agilent 5517B package is smaller than that of the Agilent 5517A The Agilent 5517B Laser Head shown in Figure 5 4 is supplied with a Test Polarizer Agilent Part Number 1000 0616 Cables available as accessories are listed in Chapter 9 Accessories of this manual The three position shutter on the Agilent 5517B can be set for open reduced or closed apertures The Agilent 5517B has four rear panel indicators The 15V POWER ON and 15V POWER ON LEDs indicate that power has been applied and that the respective fuses are intact The LASER ON LED alerts the operator that the laser head is activated and is emitting a laser beam About halfway through the warm up period the REA
33. returns to the built in measurement receiver If the measurement optics remain stationary the measurement frequency and the reference frequency are the same Relative motion between the measurement optics results in a change of the measurement frequency External electronics compare the measurement frequency to the reference frequency and calculate the displacement of the optics Measurement frequency output from the built in receiver requires proper alignment of measurement optics in addition to stable laser tuning The high voltage power supply requires 15 Volts as input It receives this input from the internal low voltage power supply The high voltage power supply generates up to 12 kilovolts dc at power on After the laser starts the high voltage power supply output drops to approximately 2 kilovolts dc 5 30 User s Manual Chapter 5 Laser Heads Laser Head Descriptions ul amod OVI pueog SXV Od VZ8801 Aouanbas4 9u 1 Y Aouanbed4 1u uu inse lW ul6u ns weeg gt NO d33 I Jenje0ay Jenjeoay gt uIUOEW gt L f juewainseayy 9U 19J Y l ayes l gt pue I yP0 D lt l Y I l d Spo I r I J ljl duiy leondo d Yo gt pue poiq o z I U9JAS ules es amp o ee g iy
34. significant effect on the wavelength of light As with any measuring device improper installation or operation can degrade measurement accuracy Before installing the equipment you should study the basic measurement capabilities of the system along with considerations of relevant sources of errors Many potential problems that could be encountered during installation and initial operation can be avoided by careful planning and a thorough understanding of laser interferometry Motion of the receiver or laser head along the beam path X has no effect on the measurement since both f and f would exhibit Doppler shift Small motions of the laser head receiver interferometer or retroreflector in a direction perpendicular to the beam path Y or Z have no effect on the measurement The only restriction is that sufficient light returns to the receiver Angular motion of the laser head about the Z or Y axis has the effects described below It introduces a measurement error cosine error It may displace the laser beam so that insufficient light returns to operate the receiver User s Manual 5 5 Chapter 5 Laser Heads Vibration Isolation Vibration Isolation Since the system measures only the relative motion between the interferometer and reflector measurements are not affected by vibration along the beam axis of the laser source or the receiver When vibration of the laser head causes displacement of the beam perp
35. ters typical 5517C 003 Vacuum Wavelength Accuracy 3 sigma lifetime 0 1 ppm Vacuum Wavelength Stability typical 1 hour 0 002 ppm Vacuum Wavelength Stability typical lifetime 0 02 ppm Nominal Vacuum Wavelength 632 991354 nanometers Safety Classification Class II Laser Product conforming to U S National Center for Devices and Radiological Health Regulations 21 CFR 1040 10 and 1040 11 OUTPUTS Reference Frequency 2 4 3 0 MHz gt 13 7 mm 25 4mm Max 7 0 54 1 00 Y ___ Full Radius I lt 208 3 mm i gt lt gt 139 6 mm 8 20 5 50 7 11 mm Detail 7 w I 028 3 Places s 132 0 mm eo g 5 20 17 7 mm L l 19 3 mm 0 70 IN 0 76 oe 3 2mm _ 0 13 Dia ee 34 6 mm L E D E 1 36 4 Places Dia Beam on Dia 70 1mm 101 6 mm 11280 a 0 04 gt 106 4 mm 2 76 Sp ae a 4 19 GF 128 3 Hi 128 3 mm 505 Y P A 4 5 05 Y oH Y y Beam 11 43 mm ee l Pam ai 78 6mm lt gt 5 1 0 mm 3 10 045 0 42 es 3 43 0 04 i Em lt CAUTION iL lw 55 8 mm 17 78mm_ Typ 2 20 LASER LIGHT N DO NOT STARE INTO BEAM 0 70 MAXIMUM OUTPUT 1 mw 170 2 mm PULSE SPEC continuous wave 6 70 LASER MEDIUM helium neon CLASS II LASER PRODUCT Me 358 6 mm a 14 12
36. ts a laser beam containing a vertically polarized component fp the higher of the two optical frequencies anda horizontally polarized component f4 A portion of the emitted beam is directed to the sampler assembly Most of this sample feeds into the reference receiver and the remainder of the sample is used to control laser tuning The reference receiver generates the reference frequency signal by mixing the two laser frequencies The reference frequency is User s Manual 5 15 Chapter 5 Laser Heads Laser Head Descriptions in the range of 1 9 to 2 4 MHz and is a TTL level square wave The higher the reference frequency the higher the slew rate at which the measurement optic can move When the laser tuning stabilizes the reference frequency is sent to the system electronics The main portion of the beam is directed by system optics to an external receiver where a measurement signal is generated The measurement and reference signals are compared by the Agilent laser system electronics to generate a displacement measurement signal 5 16 User s Manual Chapter 5 Laser Heads Laser Head Descriptions Agilent 5517B Laser Head Specifications PHYSICAL CHARACTERISTICS Dimensions See figure below Weight 3 4 Kilograms 7 5 pounds Magnetic Field Strength Non Operating Does not exceed 5 25 milligauss at a distance of 460 cm 15 ft from any point on the surface of the packaged Laser Head Clearance Required for Cabling 10 16 c
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