Chapter 8 Receivers - Agilent Technologies
Contents
1. When installing or removing the fiber optic cable from the receiver body or sensor head DO NOT PULL ON THE CABLE PROPER GRIP THE CONNECTOR AND PULL IT STRAIGHT OUT see Figure 8 9 H Figure 8 9 Grip and fiber optic cable connector Agilent E 1705A Fiber Optic Cable considerations The Agilent E 1705A Fiber Optic Cable supplied with the Agilent E 1708A receiver is 2 0 meters long The Agilent E 1705A cable comes in different lengths and is made of plastic or glass Contact Agilent Call Center to order a fiber optic cable of your preference telephone numbers of various call centers are listed on the Service and Support page at the back of this manual The radius of any bend should be 35 mm 1 4 inches or more When coiled to take up excess cable slack the coil diameter should not be less than 150 mm 6 inches Details of coiling are given below User s Manual 8 23 Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver See Table 8 3 for fiber optic cable characteristics that require special handling and consideration for installation and operation Table 8 3 Fiber optic cable considerations Attribute Description comment etc Attenuation Normal cable attenuation is covered by the Sensitivity section of the Specifications in Appendix A Attenuation due to environmental changes is covered in the information below Temperature The fiber optic cable is relatively insensitive to temperature changes The2. to go together only one way This connector has a locking ring which takes a 1 4 turn clockwise to secure the cable to its mating connector on the receiver Fasteners The supplied nylon screws must be used to assure that the receiver housing is electrically isolated from the mounting fixture Clearance for laser beam Figure 8 2 shows 1 the clearance requirement for the laser beam passing the receiver or sensor head on its way to the interferometer or wavelength tracker and 2 how the receiver alignment target can be used to be sure the receiver is positioned correctly with respect to this beam Laser beam clearance is also shown in the receiver specification drawings at the end of this chapter 8 10 User s Manual Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers RECEIVER BEAM CLEARANCES AND ALIGNMENT TARGETS Laser Beam From Laser Head Small Aperture On Laser Head Agilent 10780c gt U A Receiver Small Aperture Laser Beam From Interferometer Alignment Target Ma SS Small Laser Beam a Going To Interferometer Agilent 10780F Remote Receiver Small Aperture On Laser Head Laser Beam From Laser Head s SSS N N No H se Laser Beam From Interferometer Alignment Target on a C G Small Laser Beam NN Ne Going To Interferometer gt Figure 8 2 Agilent 10780C and Agilent 10780F Receiver beam clearances and alignment targets User s Manual 8 11 Chapter 8 Rece
3. Agilent 10790C 20m 61 ft Alignment Tolerances Electrical cables for Agilent 10885A 10889B 10896B 10897B Roll 3 degrees 10898A or N1231A axis board Pitch 1 degree Agilent 10880A 5 m 15 2 ft Yaw 1 degree Agilent 10880B 10 m 30 5 ft Maximum Sensitivity 2 2 yW with 2 meter cable Agilent 10880C 20m 61 ft Factory adjusted to 5 0 pW can be adjusted to maximum sensitivity using procedures in the Agilent 10780C F Operating and Service Manual Becomes 5 0 W with a 10 meter fiber cable Beam Spacing Beam Diameter 7 6 mm 6mm 0 24 n i SSR emai 0 30 9 9 mm Y p 0 30 L Toa g Ht PS SS ran rOx T i Clearance Hole for 4 40 Screw je 23 8 mm 19 1 mm lt gt 0 94 0 75 SL 3 5 mm l y 0 14 L K 43 1 mm v ol 1 70 K L415 5 mm 0 61 i 19 1 mm Clearance Hole Insulating 0 75 107 8 mm for M3 6 32 Screw Mounting Pads 4 25 2 Places Y H A R35 Minimum 38 1 mm 81 1 4 Bend Radius 1 50 r ESE L 10780F RECEIVER Agilent Technologies SETE _7 6 mm 0 30 Clearance Hole mm DM 114 8 mm x gt for M3 6 32 Screw 2 0 4 52 2 Places Use Only Nylon Mounting Screw eee mm HP 2360 0369 to Avoid Ground Loop 0 09 Typ Figure 8 6 Agilent 10780F Remote Receiver dimensions 8 18 User s Manual Chapter 8 Receivers Agilen
4. a much smaller package size in the measurement area User s Manual 8 19 Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver lt J2 lt J1 E an E BL Agilent E1705A ai Fiber Optic Cable E Agilent E1706A joe Remote Sensor ait x MA Agilent E1708A Remote Dynamic Receiver Figure 8 7 Agilent E1708A Remote Dynamic Receiver Principles of operation The Agilent E1708A receiver s body contains the photodetector preamplifiers and a detector circuit designed to convert thelaser beam returning from an interferometer into a differential square wave at the Doppler frequency 100 kHz to 7 2 MHz The Doppler frequency contains the measured displacement information MEAS signal representing the relative motion between an interferometer and its associated reflector A squelch circuit allows the receiver s signal output to be turned off automatically if the input signal is not strong enough A secondary output from the receiver is a dc level that is proportional to the input signal strength LED indicators on the receiver light when any input signal is detected For a block diagram see Figure 8 8 8 20 User s Manual COAN Oa E MM Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver Photodetector amplifier Attenuator adjustment Amplifier LEDs Squelch adjustment Signal level detector circuit Sinewave to squarewave converter Signal strength connector J2 see Figure 8 7 Output
5. frequency The amplitude is proportional to the product of the incident powers of the two orthogonal components The photodiode generates an ac current which is converted to an ac voltage at a frequency of 100 kHz to 6 0 MHz The detected signal voltage goes through an impedance transfor mation stage two gain stages and a level translation stage The result a TTL level signal goes toa TTL differential line driver which is ac coupled to the rest of the measurement electronics by a shielded twisted pair cable The output is a differential square wave at the Doppler shifted split frequency An available dc voltage output on the Agilent 10780C or Agilent 10780F receiver indicates incoming laser beam intensity Agilent 10780F Remote Receiver Figure 8 1 Agilent 10780C Receiver and Agilent 10780F Remote Receiver 8 6 User s Manual Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Agilent 5519A B Laser Head Receiver The Agilent 5519A B internal measurement receiver amplifies and converts the difference frequency of the laser beam returned by the system optics to TTL levels and supplies the signal to the measurement electronics During the measurement the vertical and horizontal components pass through the turret and measurement optics and return to the measurement receiver The difference between their frequencies will change whenever the measurement optics are moving The laser light returning from
6. front of the receiver light to provide visual indication that the receiver photo detector has received both frequency components of the laser beam e A dcvoltage which is a function of the incoming laser signal level is made available for assistance in fine tuning the laser beam alignment The remote sensor allows the receiver s body to be located well away from the point of beam intercept Some Agilent interferometers allow for direct mounting of the remote sensor User s Manual 8 25 Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver Operation Two LEDs light to indicate that the receiver s photodetector has received the laser beam If the LEDs do not light during operation try adjusting the attenuator and squelch controls as described in the Alignment and Adjustments of the Agilent E 1707A Dynamic Recaver and Agilent E 1708A Remote Dynamic R eaver Operating M anual Specifications and characteristics Specifications describe the device s warranted performance Supplemental characteristics indicated by TYPICAL or NOMINAL are intended to provide non warranted performance information useful in applying the device Specifications for the Agilent E1708A Remote Dynamic Receiver are provided in the following subsection 8 26 User s Manual Weight 170 grams 6 0 ounces Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver Agilent E1708A Remote Dynamic Receiver Specifications Electrical Cabl
7. laser measurement system the receiver captures the light power intensity from the two beams the Measurement Beam and the Reference Beam which areat slightly different frequencies The sum of the light power in each beam is the dc component of the light power assuming both beams are within the sensor clear aperture area For the Agilent E1708A the dc portion of the laser beam has little impact on the specification However with the Agilent E1709A the amplitude of the dc light signal directly affects the receiver sensitivity Therefore it is important to measure both the ac and the dc components at the First Stage Output User s Manual 8 29 Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver AC Light Power When thetwo beams overlap this produces a difference frequency split frequency which is detected by the receiver as the ac component of the light power It is the ac light power that is converted to an electrical signal which becomes the measurement frequency AC DC Ratio This is the proportion of ac light power to the total dc light power For example Figure 8 12 shows the AC DC ratio as approximately 50 The importance of the AC DC ratio is discussed in detail in Chapter 3 of the Agilent E1709A Remote High Performance Receiver Operating Manual The alignment procedure described in Chapter 4 of the Operating Manual involves calculating the AC DC ratio and comparing the values to the Agilent E1709
8. only Sensitivity characteristic that is affected is the cable attenuation which changes only 2 to 3 percent from 0 to 50 degrees C Note that measurement accuracy is unaffected by amplitude variations Lifetime When the cable is flexed continuously around a small radius the cable will develop permanent attenuation The attenuation increases as the flexing continues Using a larger bend radius allows a considerable increase in lifetime The lifetime specification is 1000 cycles with a 90 degree bend around a 10 millimeter 0 4 inch radius In tests using a 75 millimeter 3 0 inch bend radius the cables survived more than 260 000 cycles of bending with no increase of signal attenuation Cables in permanent installations should not have bends less than 35 millimeters 1 4 inches radius If the cable must flex repeatedly the bend radius should not be less than 100 millimeters 4 inches et T S B Coiling Excess Cable The cable coil diameter should be 150 millimeters 6 inches or larger to avoid any increase in attenuation Coil diameter 150 mm minimum A Environmental The fiber optic cables are UL recognized components that pass UL VW 1 flame Considerations retardancy specifications In most instances the use of conduit is probably not necessary since the cable has excellent safety properties in flammable environments Also the cable is electrically non conducti
9. the measurement optics is directed through a polarizer and onto a photodiode Because of the polarizer orientation the beam power past the polarizer varies sinusoidally at the difference frequency of the two laser frequency components The beam power at the difference frequency is converted toTTL levels The frequency of the TTL output is the measurement frequency Special considerations Cables General Each Agilent 10780C or Agilent 10780F receiver requires a cable to carry signals and power between it and the measurement electronics axis board with which it is to be used One cable is required per measurement axis The cable used depends on the axis board used and the cable length required Cables are described in Chapter 9 Accessories of this manual The Agilent 5519A B Laser H ead receiver connection is made via the cable that also provides power for the laser The cable depends on the axis board used Cables are described in Chapter 9 Accessories of this manual Agilent 10790A B C cables An Agilent 10790A Agilent 10790B or Agilent 10790C Receiver Cable is used to connect the Agilent 10780C or Agilent 10780F receiver tothe Agilent 10895A VME Axis Board for both measurement and Wavelength Tracker axes User s Manual 8 7 Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Agilent 10880A B C cables An Agilent 10880A Agilent 10880B or Agilent 10880C Receiver Cable is used to connect an A
10. 0780F receiver s fiber optic cable Cable connection Agilent 10790A B C Receiver Cable This cable s connectors are identical on either end as shown in Figure 9 6 The connectors on the cable and on the receiver and Agilent 10895A axis board are keyed to go together only one way The connectors on the cable each have a locking ring which takes a 1 4 turn clockwise to secure the cable to its mating connector User s Manual 8 9 CAUTION CAUTION Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Each connector on an Agilent 10790A Agilent 10790B or Agilent 10790C cable has both a male and female half Before making a connection be sure the male half of the cable connector is properly aligned with the female half of the mating connector F ailure to align the pins prior to mating the connectors may result in damaged pins Agilent 10880A B C Receiver Cable The connectors at each end are different as shown in Figure 9 7 One connector is a bayonet connector that inserts into the Agilent 10885A 10889B 10896B 10897B 10898A or N1231A axis board The connectors lock together To unlock the connectors slide the cable connector sleeve away from the Agilent axis board s panel until the connectors separate Any attempt to twist the cable connector when it is connected to the Agilent 10885A panel connector may cause damage The other connector fits the connector on the receiver this connector is keyed
11. 709A s first electrical stage It contains both the dc and ac portions of the incoming light signal and hence is used to determine the AC DC ratio This signal is affected by adjustments of the Agilent E1709A attenuator Signal Strength Voltage J 2 This is a dc voltage that is proportional to the ac component of the signal at the output of the second electrical stage This signal is affected by any adjustments of the Agilent E1709A attenuator This dc voltage should not be confused with the dc light signal component 8 32 User s Manual Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver Features Agilent E1706A Remote Sensor The Agilent E1709A requires an Agilent E1706A Remote Sensor containing a lens polarizer and Agilent E1705A Fiber Optic Cable that can be purchased separately or as an option to the Agilent E1709A Glass or plastic fiber cables are available Contact Agilent call center for details The fiber optic cable carries the beam from the remote sensor to the electronics in the receiver body The fiber optic cable length is 2 0 meters to allow for considerable mounting flexibility and ease of use if you require some length other than the standard 2 0 meters contact Agilent call center This arrangement provides several benefits e It allows the receiver body to be located well away from the point of beam intercept so receiver heat is not dissipated near the measurement area e It provides easie
12. A specifications First Stage vs Second Stage In the first stage of the Agilent E1709A electronics both the dc and the ac signals are present In the second stage the dc is stripped away and only the ac signal is used to create the receiver output signal The first and second stages are shown in Figure 8 13 8 30 User s Manual O G Q E GMM 9 Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver N 2 100 0 5 V pele pnan Photodetector first stage amplifier Attenuator adjustment First Stage Output J3 connector Second stage amplifier Squelch adjustment Signal strenght detector circuit Sinewave to squarewave converter LEDs Signal strength voltage J2 connector 10 Cable driver 11 Output signal input power J1 connector Figure 8 13 Agilent E1709A Receiver block diagram Figure 8 14 illustrates the location and signal characteristics of J 2 and J3 User s Manual 8 31 Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver Reference Description J3 First Stage Output Indicates ac and dc portions of the light signal J2 Signal Strength Voltage indicates only the ac portion of light signal as a dc voltage This is an SMC connector An SMC f to BNC f Adapter Agilent part number 1250 0832 is available Figure 8 14 Agilent E1709A with fiber and lens assembly First Stage Output Voltage J 3 This is the actual output voltage of the Agilent E1
13. Contact Agilent for information connector on one end and a 4 pin Axis Board LEMO connector on the other Agilent 10898A VME High Resolution Use high performance cables for Dual Laser Axis Board both the receiver and the laser Agilent N1231A PCI Three Axis Board head Agilent 10895A 5 meters Agilent 10790A These cables have a 4 pin BNC Laser Axis Board for VMEbus 10 meters Agilent 10790B connector on each end Each of these receivers has a polarizer as part of its input lens assembly The E1708A receiver s lens assembly is in the remote sensor assembly When mounting either receiver remember the following points s For maximum input signal strength align the polarizer so its polarization vectors are the same as those of the incoming laser beam At a 45 degree roll position the signal goes to zero e For either receiver body power dissipation is typically 3 8 watts The receiver s mounting feet keep an air gap around the receiver and also act as thermal and electrical isolators s Leave enough clearance for the signal cable that connects to the receiver s 4 pin signal and power connector See dimensional drawing in Figure 8 10 e The receiver housing must be electrically isolated from the equipment it is mounted on The clearance holes in the receiver s insulating mounting feet let you use either 6 32 or M3 5 screws 8 22 User s Manual CAUTION Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver
14. Receivers Chapter 8 Receivers General General One receiver is required for each measurement or wavelength tracker axis The receiver converts the Doppler component of the laser beam from an interferometer or wavelength tracker into an electrical signal for the measurement electronics This chapter describes the following receivers e Agilent 10780C Receiver e Agilent 10780F Remote Receiver e Agilent E1708A Remote Dynamic Receiver and e Agilent E1709A Remote High Performance Receiver The Agilent 5519A and 5519B laser heads which are a component of the Agilent 5529A 55292A Dynamic Calibrator system has a built in receiver This chapter includes a brief description of that receiver However the installation and alignment of that receiver occurs as part of the Agilent 5519A B Laser Head installation and alignment procedures given in the Agilent 5519A Laser Head Service Manual Receiver specifications are given later in this chapter Comparison of Agilent Laser Receiver Families Table 8 1 summarizes the features characteristics and specifications the Agilent 10780C F Agilent E1708A and Agilent E1709A receivers The Agilent E1708A receiver is functionally similar to the Agilent 10780F receiver However the E1708A is not a direct replacement for 10780F Comparisons of the two laser receiver families are provided in Table 8 1 8 2 User s Manual Chapter 8 Receivers Comparison of Agilent Laser Receiver Famil
15. by TYPICAL or NOMINAL are intended to provide non warranted performance information useful in applying the device Specifications for the Agilent 10780C Receiver and Agilent 10780F Remote Receiver are given below Specifications for the Agilent 5519A B Laser Head s internal receiver are given in Chapter 5 Laser Heads of this manual Sensitivity The maximum sensitivity of the Agilent 10780C is 1 5 UW factory set at 5 uW and can be adjusted via an externally accessible potentiometer The adjustment procedure is given earlier in this chapter Maximum sensitivity of the Agilent 10780F Remote Receiver is 2 2 UW with its standard 2 m cable a 10 m cable reduces the sensitivity to 5 0 uW The difference between the Agilent 10780C and the discontinued Agilent 10780A and Agilent 10780B models is the increased bandwidth and sensitivity of the Agilent 10780C to laser light 8 16 User s Manual Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Agilent 10780C Receiver Specifications Weight Dimensions see figure below 136 grams 4 8 ounces Typical Power Requirements 15 volts at 136 mA Heat Dissipation 2 0 W typical Alignment Tolerances Roll 3 degrees Pitch 1 degree Yaw 1 degree Maximum Sensitivity 1 5 pW Factory adjusted to 5 0 pW can be adjusted to maximum sensitivity using procedures in the Agilent 10780C F Operating and Service Manual Beam Diameter 6 mm 0 24 Output Si
16. crew 3 8 19 1 2 Places 0 151 TRS Dn 0 780 0 072 VAG I SMC R35 Minimum H MCN 1 4 Bend Radius TETN E La Agilent Quad T BN 0 30 XS 40 0 mm Lo 1 575 11 4mm 50 mm 0 450 2 0 r pon 78 1 mm 3 075 F 1 7 mm i m 0 320 16 5 mm I 0 065 0 650 19 8 mm 0 780 mg Figure 8 10 Agilent E1708A receiver dimensions User s Manual 8 27 Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver Agilent E1709A Remote High Performance Receiver Description The Agilent E1709A Remote High Performance Receiver see Figure 8 11 is an important component of the measurement electronics for an Agilent Laser Interferometer Measurement System The Agilent E1709A converts light from the remote sensor to electrical signals that can be processed by the system electronics See Figure 8 14 The Agilent E1709A is for use in the most demanding applications requiring sub nanometer resolutions of systems in motion As the Doppler shift caused by motion of the system stage changes the measurement frequency the Agilent E1709A receiver ensures minimal phase position processing errors The E1709A also provides immunity to errors induced by changes in measurement signal power level One receiver is required for each measurement axis in the Laser Transducer system being installed See the Agilent E1709A Remote High Performance Receiver Operating Manual for compatible cable information as well as signal an
17. cted that is coincident upon itself at the laser head This will provide excellent alignment of the receiver in pitch and yaw but not roll relative to the beam axis Roll must be aligned so the two polarization vectors from the laser head are parallel to or perpendicular to the plane defined by the centerlines of the two mounting holes within 33 Turn the GAIN potentiometer fully clockwise Block the measurement beam the beam between the interferometer and the measurement reflector Adjust the GAIN potentiometer counter clockwise until the test point voltage drops below 0 1V Unblock the measurement beam The test point voltage should be at least 0 7V Record the voltage reading at the beam monitor test point as an axis reference for future troubleshooting User s Manual 8 15 Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Operation The Agilent 10780C Receiver or Agilent 10780F Remote Receiver normally receives its operating power from the measurement electronics to which it is connected When the measurement electronics are turned on the receiver will turn on An LED on the Agilent 10780C or Agilent 10780F receiver signals beam capture An available dc voltage output on the Agilent 10780C or Agilent 10780F receiver indicates incoming laser beam intensity Specifications and characteristics Specifications describe the device s warranted performance Supplemental characteristics indicated
18. d connector information ae aie ee Agilent E1705A ait 7 Fiber Optic Cable J Agilent E1706A an om Remote Sensor A x AJ a Agilent E1709A Remote High Performance Receiver Figure 8 11 Agilent E1709A Remote High Performance Receiver 8 28 User s Manual NOTE Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver Key definitions and concepts Sensitivity dependencies are explained in terms of AC DC ratio It is important to understand this concept and how its measurement relates to the resultant electrical output of the Agilent E1709A receiver Understanding the following terms will also clarify the differences between the Agilent E1708A and the Agilent E1709A which are discussed and listed later in Agilent E1709A relationship to Agilent E1708A subsection in this chapter The definitions include references to connectors J 2 and J 3 shown in Figure 8 14 Detailed descriptions of the Agilent E1709A connectors and signal outputs are covered in Agilent E1709A Remote High Performance Rece ver Operating Manual Figure 8 12 illustrates the ac and dc light power relationship 1 DC Light Power Sum of both beams including overlap area J3 2 Measurement Beam 3 AC Light Power beam overlap of 50 Only the overlapping portion of the beam J3 and J2 4 Reference Beam 5 Remote Sensor Clear Aperture Figure 8 12 AC DC light power relationship DC Light Power In the Agilent
19. er all other optics alignment has been done 8 14 User s Manual NOTE NOTE Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers To align and adjust the Agilent 10780C or Agilent 10780F receiver Align the optics on the machine in the desired configuration See the alignment procedures or techniques applicable to the interferometer s or wavelength tracker installed in your system Use alignment targets alignment aids or both to establish proper beam spacing and positioning Run the system stage out to its limit such that the retroreflector or plane mirror for one axis is at its furthest position from the interferometer Mount the Agilent 10780C or Agilent 10780F receiver on that axis if this has not already been done Connect a digital voltmeter DVM or oscilloscope to the test point on the back of the receiver Align the receiver for a maximum positive voltage at the test point You may have to adjust the gain potentiometer to keep the test point voltage out of saturation and in the linear region 0 1 to 0 8V A simple way to align the receiver is to use a gage block to autoreflect the beam Remember that the objective is to position the receiver or sensor head such that the beam enters the input aperture perpendicular to its front face and centered in the aperture Hold the gage block against the front face and adjust the receiver or sensor head position and angular orientation so that the beam is autorefle
20. es 26 g 0 9 ounces for remote sensor with 2 m cable Dimensions see figure below Typical Power Requirements 15 volts 1V at 250 mA maximum Heat Dissipation 3 8 W typical for receiver 0 0 W for remote sensor Alignment Tolerances Roll 3 degrees Pitch 1 degree Yaw 1 degree Maximum Sensitivity 2 2 uW E1708A with 2 m cable 5 0 UW E1708A with 10 m cable Output Signal Differential square wave at Doppler shifted split frequency 100 kHz to 7 2 MHz Designed to operate with Agilent laser boards Signal Strength Monitor 0 8 volts proportional to optical input signal Agilent 10790A 5 m 16 4 ft Agilent 10790B 10 m 32 8 ft Agilent 10790C 20 m 65 6 ft Electrical cables for Agilent 10885A 10889B 10896B 10897B 10898A or N1231A axis board Agilent 10880A 5 m 16 4 ft Agilent 10880B 10 m 32 8 ft Agilent 10880C 20m 65 6 ft or high performance electrical cables Agilent N1250A 5 m 16 4 ft Agilent N1250B 10 m 32 8 ft Fiber Optic Cables Length 2 m standard 10 m maximum 7 6mm 0 30 7 6mm vo 0 30 a th toe Hole 0 39 for 4 40 Screw 23 8 mm eS 3 8 mm 69 9 mm 3 0 94 49 1mm 0 151 2 750 0 75 61 0 mm 2 400 10 2 11 1 3 5 mm oe w an 0 403 0 436 0 14 0 88 2 070 k 43 1 mm T A 15 5 mm 1 70 0 61 cl Hol 9 0 9 9 mm learance Se 1s a a 0 354 0 390 M3 5 6 32 S
21. gh Performance Receiver Specifications Dimensions see Figure 8 15 on next page Typical Power Requirements 15 volts 1V at 267 mA maximum Heat Dissipation 4 0 W typical for receiver 0 0 W for remote sensor Temperature Range 0 40 C operating Warm up Time 45 minutes typical for still air 15 minutes typical for 60 m min 200 ft min moving air Recommended Electrical Cables for Agilent 10885A 10889B Optical Input Dynamic Range ratio 25 1 to 6 1 depending on the AC DC ratio Maximum input 50 pW ac 150 pW dc Output Signal Errors due to Doppler frequency variations and amplitude variations within the Dynamic Range ratio specification 1 2 nm for linear optics 0 6 nm plane mirror optics 0 3 nm for high resolution optics For overdrive condition errors are two times these values Signal Strength Voltage 0 10 volts proportional to ac optical input signal Alignment and Sensitivity see table below 10896B 10897B 10898A or N1231A axis board Agilent N1250A High Performance Receiver Cable 5 m Agilent N1250B High Performance Receiver Cable 10 m Agilent N1251A Matching High Performance Laser Head Cable 3 m Agilent N1251B Matching High Performance Laser Head Cable 7 m Differential square wave at Doppler shifted split frequency 100 kHz to 15 5 MHz Slew rates to 1 m s with plane mirror optics 2 m s with linear optics Fixed Data Delay 33 2 ns typical Fixed Delay Temperature Coeffic
22. gilent 10780C or Agilent 10780F receiver to an Agilent 10885A PC Axis Board Agilent 10889B PC Servo Axis Board Agilent 10896B VME Laser Compensation Board Agilent 10897B VME High Resolution Laser Axis Board Agilent 10898A VME High Resolution Dual Laser Axis Board or Agilent N1231A PCI Three Axis Board for both measurement and Wavelength Tracker axes Effects of motion and orientation 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 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 Angular motion of the receiver about the Y axis the Z axis or both has no effect on the measurement within certain alignment limits 8 8 User s Manual CAUTION Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Mounting Offset aperture Offset aperture allows flexibility in moun
23. gnal Differential square wave at Doppler shifted split frequency 100 kHz to 7 2 MHz Electrical Cables Agilent 10790A Agilent 10790B 10 m 30 5 ft Agilent 10790C 20m 61 ft Electrical cables for Agilent 10885A 10889B 10896B 10897B 10898A or N1231A axis board Agilent 10880A 5 m 15 2 ft Agilent 10880B 10 m 30 5 ft Agilent 10880C 20m 61 ft 5 m 15 2 ft Beam Spacing 12 7 mm 0 50 eS ig UL Insulating Mounting Pads ol Seis 107 8 mm lt _ er w 1 50 t 10780C RECEIVER Agilent Techn ologies 50 mm 2 0 lt 2 3 mm 0 09 T yp lt Use Only Nylon Mounting Screw HP 2360 0369 to A void Ground Loop Clearance hole for M3 6 32 Screw 2 Places Figure 8 5 Agilent 10780C Receiver dimensions User s Manual 8 17 Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Agilent 10780F Remote Receiver Specifications Weight 126 grams 4 5 ounces for Agilent 10780F receiver Output Signal 26 grams 0 9 ounce for remote sensor with a2 meter cable Differential square wave at Doppler shifted split frequency 100 kHz to 7 2 MHz Dimensions see figure below Electrical Cables Typical Power Requirements 15 volts at 136 mA Agilent 10790A 5 m 15 2 ft Heat Dissipation 2 0 W typical for receiver Agilent 10790B 10 m 30 5 ft 0 W for remote sensor
24. ient 0 015 ns C Fiber Optic Cable Type 2 m plastic Remote Sensor Alignment Tolerance Roll 3 Pitch 1 Yaw 1 Sensitivity AC DC ratio 90 0 20 uW See the Agilent E1709A Remote High Performance Receiver Operating Manual Agilent Part Number E1709 90006 English or E1709 90007 Japanese for more details on sensitivity 8 36 User s Manual Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver 7 6mm 0 30 7 6 mm L 0 30 9 9 mm 0 39 0 23 8mm lt T Clearance Hole for 4 40 Screw 3 67 mnm 144 0 94 19 1 mm 0 75 22 4 mm 3 5 mm 7 0 14 y 0 88 15 5 mm 0 61 Clearance Hole for M3 5 6 32 Screw 2 Places 4 32 mm 170 R35 Minimum 1 4 Bend Radius 3 8 mm 0 151 69 9 mm 2 750 61 0 mm 2 400 10 2mm 11 1mm 0 403 0 436 1 642 115 6 mm 9 0 mm 9 9mm lt 0 384 0 390 19 1 mm 18 mm l 0 072 10 4 mm 0 750 0 410 Figure 8 15 Agilent E1709A receiver dimensions User s Manual 11 4 mm 0 450 s i 78 1 mm 3 075 o 1 1 7 mm 16 5 mm 0 065 0 650 19 8 mm 0 780 mE 8 37 Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver 8 38 Product specifications and descriptions in this document subject to change without notice Copyright C 2002 Agilent Techno
25. ies Table 8 1 Comparison of Agilent Laser Receiver families Characteristic Dynamic Range E1709A Receiver 25 1 to 6 1 depending on the AC DC ratio E1708A Receiver 10 1 10780C 10780F Receivers Not specified Sensitivity 20 80 UW depending on the AC DC ratio with 2 meter plastic cable 2 2 uW E1708A with 2 meter fiber optic cable 5 UW E1708A with 10 meter fiber optic cable 1 5 UW 10780C 2 2 uW 10780F with 2 meter fiber optic cable 5 UW 10780F with 10 meter fiber optic cable Alignment Tolerance For plastic fiber optic cable Option 010 Roll 3 Pitch 1 Yaw 1 Agilent remote sensor is self aligning with some interferometers For plastic fiber optic cable Roll 3 Pitch 1 Yaw 1 Agilent remote sensor is self aligning with some interferometers Roll 3 Pitch 1 Yaw 1 10780F is self aligning with some interferometers Output Signal Frequency Differential square wave at Doppler shifted frequency 100 kHz to 15 5 MHz slew rates to 1 m s with plane mirror optics 100 kHz to 7 2 MHz slew rate to 500 mm s with plane mirror optics 100 kHz to 7 2 MHz Fixed Data Delay typical 33 2 ns typical 0 01 ns C 86 ns Not specified Errors due to frequency variations at fixed temperature For 25 1 to 6 1 input amplitude variations and frequency range of 100 kHz to 15 5 MHz lt 1 2 nm for linear op
26. ivers Agilent 10780C and Agilent 10780F Receivers Alignment General Each Agilent 10780C or Agilent 10780F Receiver in the measurement system requires an alignment relative to its input beam to maximize its measurement signal strength This alignment is typically done by positioning the receiver so the two polarization vectors from the laser head are parallel or perpendicular to the plane defined by the centerlines of the two mounting holes within 3 Also the beams should be centered on the receiver s input lens Alignment target The Agilent 10780C or Agilent 10780F receiver is supplied with a snap on beam target to ease coarse alignment The alignment targets are shown in Figure 9 14 of Chapter 9 Accessories in this manual The alignment target attaches at the receiver lens and helps align the receiver to the center of the incident beam It is also used to adjust the spacing between the beam going to the interferometer and the return beam incident on the receiver The Agilent Part Number for the standard Alignment Target for the Agilent 10780C Receiver is 10780 40003 The alignment target for use with an Agilent 10780F Remote Receiver having a 9 mm lens is Agilent Part Number 10780 40009 Principle The receiver is aligned by moving it and rotating it relative to the beam axis Receiver alignment is performed during the optical system alignment The receiver is moved to center the incident beam on its input le
27. logies 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 90134 User s Manual
28. ns The receiver photodetector only measures the overlapping portion of the laser beams For maximum signal strength the interferometer and retroreflector are aligned so the reference beam from the interferometer and the measurement beam from the retroreflector exactly overlap upon recombination These recombined laser beams then enter the receiver at the center of its input lens From Figure 8 3 it is clear that if the recombined laser beams entering the receiver are not centered on the photodetector measurement signal loss will occur If the 8 12 User s Manual Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers interferometer or the retroreflector is misaligned Figure 8 3 the reference and measurement beams no longer completely overlap resulting in signal loss Typically a lateral offset of 1 4 of the beam diameter between the beams is allowable for an adequate measurement signal However you must make every effort to optimize the laser beam overlap for maximum performance Optics Misalignment Reference Beam Retroreflector IN PN N Laser Beam gt Receiver yor Beam Measurement Beams Receiver Detects Only Overlapped Portion View A A Measurement Beam View A A Figure 8 3 Effect of optics misalignment If the measurement beam is not aligned parallel to the direction of retroreflector travel there are two effects e First a cosine error is generated of a magni
29. nto a silicon PIN photodiode Between the lens and the diode is a small piece of polarizing material oriented at 45 to the horizontal and vertical axes of the receiver The Agilent 10780 Remote Receiver s lens and polarizer are contained in a small assembly that is connected to the electronics housing by a fiber optic cable The fiber optic cable allows the receiver module to be mounted away from the measurement area removing a source of heat The interference signal between the f1 and f2 polarizations is sent through the fiber optic cable to the electronics housing The Agilent 10780F receiver s fiber optic sensor head may be mounted directly to certain interferometers Agilent 10719A Agilent 10721A Agilent 10735A Agilent 10736A Alignment pins are provided for easy installation and alignment This eliminates the need for any other user supplied mount for the sensor head When the receiver input is oriented properly that is with its vertical axis parallel or perpendicular to the axes of the laser head the polarizer passes one half the incident power from each of the two incoming orthogonally polarized components of the received laser beam User s Manual 8 5 Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Photodiode The output from the polarizer assembly is an amplitude modulated sine wave that is sent to a photodiode chip in the receiver s electronic housing The frequency is the Doppler shifted split
30. ote sensor with 2 m cable 26 g 136 g 10780C 126 g 10780F body 26 g remote sensor with 2 m cable Dimensions Height 78 1 mm 3 075 in Width 115 6 mm 4 552 in Depth 19 8 mm 0 780 in Height 78 1 mm 3 075 in Width 115 6 mm 4 552 in Depth 19 8 mm 0 780 in Height 38 1 mm 1 50 in Width 114 8 mm 4 52 in Depth 19 8 mm 0 78 in Dimensions receiver body mounting area 4 holes at corners of a rect angle 40 0 mm 1 575 in high 108 0 mm 4 250 in wide centered on receiver body centerline 4 holes at corners of a rect angle 40 0 mm 1 575 in high 108 0 mm 4 250 in wide centered on receiver body centerline 2 holes 107 8 mm 4 25 in apart on receiver centerline For ac input signal power E1708A lt 200 pW E1709A lt 50 pW 8 4 User s Manual Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Agilent 10780C and Agilent 10780F Receivers Description General The Agilent 10780C Receiver or Agilent 10780F Remote Receiver converts the Doppler shifted laser light from an interferometer or the wavelength tracker into electrical signals that can be processed by the rest of the laser system Lens and polarizer Light enters either receiver through a lens and polarizer The Agilent 10780C lens and polarizer are built into the same assembly that houses the receiver electronics Agilent 10780C Receiver s lens focuses the laser light o
31. r access to the attenuator and squelch adjustments e t provides a much smaller package size in the measurement area Application characteristics The Agilent E1709A e Has high sensitivity of 20 u to 0 80 uW depending on ac signal strength with a 2 meter cable e Accommodates a high Doppler frequency shift to allow greater speed in stage velocity with slew rates to 1m s with plane mirror optics e Has a wide operating temperature range of 0 40 C e Has a wide Dynamic Range of 25 1 to 6 1 depending on ac signal strength User s Manual 8 33 Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver Agilent E 1709A relationship to Agilent E 1708A There are several additional features provided by the Agilent E 1709A that are not provided by earlier model receivers such as the Agilent E1708A Remote Dynamic Receiver F or detailed comparison of Agilent E1708A and Agilent E1709A see Table 8 1 Technical enhancements The Agilent E1709A compared to the Agilent E 1708A e has 3 to 11 times greater sensitivity enabling the measurement system to function with weaker beam signal This allows a much longer distance between receiver and sensor or more axes per laser head accommodates a higher Doppler frequency shift to allow greater speed in stage velocity slew rate The Agilent E1709A can tolerate approximately two times the slew rate limit of the Agilent E1708A e has approximately 10 times greater immunity
32. rger than the Agilent 10780F and slightly larger than the Agilent E1708A e Agilent recommends the use of a scope probe to align the Agilent E1709A Approximately 130 mm 5 in of space above the top of the receiver is needed to allow the scope probe to be plugged in Lo the 3 connector The Agilent E1708A which is almost identical to the Agilent E1709A does not have a scope probe connector and does not have this space requirement Therefore when retrofitting the Agilent E1709A into an Agilent E1708A application make sure there are provisions for this scope probe access s For maximum slew rate the Agilent 10898A Dual Laser Axis Board and high performance cables are required e When replacing an Agilent 10780C F with either an Agilent E1708A or Agilent E1709A metal mounting screws can be used Plastic screws are recommended for the Agilent 10780C F Specifications and characteristics Specifications describe the device s warranted performance Supplemental characteristics indicated by TYPICAL or NOMINAL are intended to provide non warranted performance information useful in applying the device Specifications for the Agilent E1709A Remote High Performance Receiver are provided in the following subsection User s Manual 8 35 Weight For Agilent E1709A 190 grams 6 7 ounces For remote sensor with 2m cable 26g 0 9 oz Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver Agilent E1709A Remote Hi
33. signal input power connector J1 see Figure 8 7 9 JUUUL Figure 8 8 Agilent E1708A Receiver block diagram Installation Refer toAgilent 10780C F Receiver s placement mounting installation examples and procedures for alignment to the laser beam F or more specific mounting installation and alignment and adjustment procedures see the Agilent E1707A Dynamic Receiver and Agilent E1708A Remote Dynamic Receiver Operating Manual User s Manual 8 21 Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver Cables for electronics The receiver cable to be used depends on the electronics system to be used Table 8 2 lists the available cables Refer to the manual for your system for more cabling information Table 8 2 Cables for use with an E1708A receiver For use with these electronics Use one of these Receiver Cables Description Agilent 10885A 5 meters Agilent 10880A These cables have a 4 pin BNC PC Axis Board 10 meters Agilent 10880B connector on one end and a 4 pin LEMO connector on the other Agilent 10887A For cable lengths longer than 10 PC Calibrator Board meters use high performance cables Agilent 10889B PC Servo Axis Board Contact Agilent for information about Agilent 10896B high performance cables Laser Compensation Board for VMEbus with Agilent 10717A Wavelength Tracker Agilent 10897B Use high performance cables These cables have a 4 pin BNC High Resolution VMEbus Laser
34. t E1708A Remote Dynamic Receiver Agilent E1708A Remote Dynamic Receiver Description The Agilent E1708A Remote Dynamic Receiver shown in Figure 8 7 is intended for use in applications requiring sub nanometer resolutions of systems in motion It extends the performance of systems that use the Agilent 10897B High Resolution Laser Axis board for VMEbus by providing performance consistent with the high resolution and low variable data age of that board As the Doppler shift caused by motion of the system stage changes the measurement frequency the Agilent E1708A receiver ensures minimal phase processing errors The E1708A also provide immunity to errors induced by changes in measurement signal laser input power level One receiver package is required for each measurement axis in the Laser Transducer system being installed The Agilent E1708A receives the laser beam via a remote sensor Agilent E1706A containing a lens and polarizer A fiber optic cable Agilent E1705A carries the beam from the remote sensor to the electronics in the receiver body The fiber optic cable length is 2 0 meters to allow for considerable mounting flexibility and ease of use This arrangement provides several benefits e it allows the receiver body to be located well away from the point of beam intercept so receiver heat is not dissipated near the measurement area e it makes easier access to the attenuator and squelch adjustments possible and e thereis
35. tics lt 0 6 nm for plane mirror optics lt 0 3 nm for high resolution optics For 3 1 input amplitude variations and frequency range of 100 kHz to 7 2 MHz lt 1 2 nm for linear optics lt 0 6 nm for plane mirror optics lt 0 3 nm for high resolution optics Not specified Signal Strength Monitor 0 to 10 volts output propor tional to optical input signal power 0 to 8 volts output proportional to optical input signal power Range 0 to 0 8 volts Power Requirements 15 Vdc 1V at less than 267 mA 15 Vdc 1V at less than 250 mA 15 Vdc at 136 mA Heat Dissipation 0 0 W for remote sensor 4 0 W typical for receiver 0 0 W for remote sensor 3 8 W typical for receiver 0 0 W for remote sensor 2 0 W typical for receiver Temperature Range 0 to 40 C operating User s Manual 0 to 40 C operating 0 to 40 C operating 8 3 Chapter 8 Receivers Comparison of Agilent Laser Receiver Families Table 8 1 Comparison of Agilent Laser Receiver families Continued Characteristic Fiber Optic Cable Length E1709A Receiver Option 010 2m plastic Contact Agilent for longer fiber optic cables E1708A Receiver 2 m standard plastic Contact Agilent for longer fiber optic cables 10780C 10780F Receivers 2 m standard 10 m maximum Weight Receiver body 190 g Option 010 Remote sensor with 2 m cable 26 g Receiver body 170 g Rem
36. ting the Agilent 10780C or Agilent 10780F receiver that is the bulk of the receiver or sensor head can be mounted above below right or left of the incoming laser beam Agilent 10780F Remote Receiver sensor head The Agilent 10780F receiver s fiber optic sensor head may be mounted directly to certain interferometers Agilent 10719A Agilent 10721A Agilent 10735A Agilent 10736A Alignment pins are provided for easy installation and alignment This eliminates the need for any other user supplied mount for the sensor head Installation When installing the receiver keep the following points in mind s Ata 45 position roll the signal will go to zero e Plastic mounting hardware electrically isolates the Agilent 10780C or Agilent 10780F receiver from the machine and reduces problems with heat conduction e The receiver typically dissipates 2 0 watts with a maximum dissipation of 2 7 watts Plastic pads keep an air gap around the receiver and act as thermal and electrical isolators Use Nylon screws only Agilent 2360 0369 The receiver housing must be electrically isolated from the mounting fixture s Theremote sensor in the Agilent 10780F Remote Receiver does not dissipate any power The remote sensor does not require a nylon screw e Allow a 5 cm space at the rear of each receiver housing for each cable connection e Maintain a bend radius of at least 35 mm 1 4 inches to prevent signal attenuation in the Agilent 1
37. to temperature variations e allows approximately 5 times more dynamic range optical power change Adjustment and additional alignment requirements The Agilent E1709A has much greater sensitivity specifications than the Agilent E 1708A In order to obtain the optimum sensitivity performance for the Agilent E1709A additional measurements and alignment procedures are required to maximize the ratio of ac light signal to dc light signal at the receiver input Figure 8 12 illustrates ac light and dc light at the receiver input The Agilent E1709A features an oscilloscope probe connection to measure the AC DC ratio Retrofit issues The Agilent E1709A can be used in most applications where the Agilent 10780F or Agilent E1708A is used In most respects the Agilent E1709A has better specifications than these other receivers and will perform as well or better However several specifications should be checked e Sizeis the same as the Agilent E1708A and larger than the Agilent 10780F s Maximum AC Optical Signal Intensity specification is 50uW for the Agilent E1709A which is 4 times less than for the Agilent E1708A 8 34 User s Manual Chapter 8 Receivers Agilent E1709A Remote High Performance Receiver The maximum optical signal can be larger if larger position error is acceptable e AC DC ratiois more important for the Agilent E1709A than for other Agilent laser system receivers e DC power consumption is considerably la
38. tude directly related to the angle of misalignment F or a complete description of cosine error refer to Chapter 15 Accuracy and Repeatability in this manual e Second when movement occurs between the optics the angular misalignment also causes a lateral displacement of the measurement beam with respect to the reference beam at recombination resulting in additional signal loss Figure 8 4 illustrates the result of angular misalignment User s Manual 8 13 Chapter 8 Receivers Agilent 10780C and Agilent 10780F Receivers Angular Misalignment Reference Beam Laser Axis Retroreflector Position 1 Retroreflector Position 2 Laser Beam gt l B Receiver 4 Interferometer Measurement Beam Travel Axis Figure 8 4 Effects of Angular Misalignment to the Direction of Travel NOTE The presence of measurement signal through the total length of travel does not guarantee that the measurement axis is aligned for minimum cosine error Also any angular misalignment of the laser beam to the direction of travel causes a decrease in the measurement signal strength Receiver alignment and gain adjustment procedure The procedures presented here are common to most of the alignment procedures or techniques presented in Chapter 4 System Installation and Alignment and Chapter 7 Measurement Optics of this manual Usually aligning the receiver and adjusting its gain will be done aft
39. ve so it requires no shielding 8 24 User s Manual Chapter 8 Receivers Agilent E1708A Remote Dynamic Receiver Table 8 3 Fiber optic cable considerations Continued Attribute Description comment etc The cable s polyethylene jacket provides protection against abrasion and chemicals Avoid placing the cable directly in organic or alkaline solvents for extended periods of time hundreds of hours since these chemicals can penetrate ES the polyethylene jacket and degrade the optical properties of the fiber The fiber cable is specified to withstand a 0 5 kilogram weight shaped in the form of a half cylinder that is dropped from a height of 150 millimeters 150 mm max Cable Bending and Shaking bending and vibration of the cable will not result in measurement errors Movement but can cause signal attenuation If the movement is periodic and continuous amplitude modulation can occur with the amplitude depending on the bend radius JR AR Ys S Amplitude modulation can cause signal attenuation but not measurement errors Alignment and adjustments To aid in aligning the laser beam three features are available e Initial receiver positioning and coarse beam alignment are achieved with a snap on beam target fixture Agilent part number 10780 40009 which is supplied with the receiver The target is for beam alignment only and should be removed before operating the receiver s LEDs on the top and
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