Handbook for Operating a Spectra-PhysicsTM Quanta-Ray
Contents
1. concern has an IN written on it The OUT valve has been taped so that valve is opened at all times vi fh standard cubic feet per hour See Floor Plan on pg 1 and Figure 4 Figure 4 Picture of Nitrogen Distribution Meter 6 sel N The switch below the key should always be left on to warm the crystal See Floor Plan on pg 1 and Figure 5 Figure 5 Picture of Power Supply and where the key is located In the above picture the key is in the OFF position Vil 7 Turn on the Nd YAG and MOPO controller backside See Floor Plan on pg 1 and Figure 6 Figure 6 Top left shows the front of the Nd YAG and MOPO Top right shows the back of the Nd YAG and MOPO controller where the ON OFF switches are located 8 Press POWER ON hold until beeps in menu of Nd YAG controller SELF TEST will begin and laser will run in Q SWITCH OFF mode See Floor Plan on pg 1 and Figure 7 and 8 Power up menu SETUP an MONITORI MA Ss NORM Figure 8 Menu that appears after pressing POWER ON 9 Let the laser warm up for 10 15 min See Floor Plan on pg 1 vill 10 Press RUN LP hold until beeps in menu Long pulse mode will begin to run Let the laser warm up for 20 30 min See Figure 9 OPERATE SETUPI MONITORT RUN EMISS NORM e Figure 9 Menu after pressing RUN LP 11 Press RUN NORM hold until beeps in2. 404 66 640 11 F 769 45 435 84 640 22 785 48 546 07 650 65 i 805 95 576 96 703 24 F 810 44 579 07 1013 98 811 29 615 0 1128 74 819 00 1014 0 1357 02 826 32 1357 0 1367 35 829 81 1692 0 1529 58 829 81 1707 3 1688 15 850 9 1711 0 1692 02 877 7 1694 20 829 9 1707 28 975 2 1710 99 1363 4 1732 94 1442 7 1813 04 1523 9 1970 02 1533 4 1678 51 1689 04 1689 68 1693 58 1816 73 1 Adjacent lines will remain unresolved on many spectroscopic systems These are neon lines brought out by forced air cooling These lines are very weak but forced air cooling makes them more useful ge a a UUU a el Above Calibration lines for pen lamps obtained from http www oriel com netcat VolumelII pdfs v39pen pdf XXX Table 2 Recommended Wavelengths Air and Wave Numbers Vacuum for Selected Hg Spectral Lines Emitted by Pencil Type Lamps Wavelength Wave Number Intensity Inm em 300 000 253 6521 39412 2386 160 289 3601 34548 858 2600 296 7283 33691 025 280 302 1504 33086 464 2800 312 5674 31983 8258 1900 313 1555 31923 765 2500 13 1844 2120 819 160 394 1484 29918 220 5300 965 0158 27388 271 970 365 4842 27953 171 110 366 2887 27203 006 650 366 3284 27290 138 4400 404 6565 24705 339 270 407 7837 24515 883 34 434 7508 23095 229 10 000 435 8335 22938 095 10 000 546 0750 18307 415 1100 576 9610 17327 389 1200 579 0670 17264 3T2 Intensities are relative va
3. units crystals needed for MOPO cccc eee Tumin Oi NE YASO erogena e tyacie cian E TUOS ON MOPO sse er e a aea ai With an FDO at fixed wavelength ccc cece cece EEEN Without an FDO at fixed wavelength ccc ccc ccce eee e eens Funar Ore C Diea a E S Usma Wt SG Oseni erre ETT AEE A eed ade Setups Expernnnental Sep eaasosmos nsa eana a a ai Repetitive Gating Setup r sarecror rirerire se E Eana N Eai Seducnial Gatine SEW Dera E ae CAUTI Oa A E E EOI SUNE DOWD ASer essee aa a ta abheauness Appendix E GIOSSALY enserre A AAA RAER Appendix 2 Nd Yag Power Supply Fuse Positions ccceeee eee e eee eens Appendix 3 Calibration Lines Reference ccc cecc eee e eee ee eee eeeeees Appendix 4 Starting Up Cheat Sheet 0 cc cece nee e eee e eee eeeens RE 6 0 G1 oc ee ann T a AEE E eee e E ISP A ONTO SENS AR OP Sea ene Acknowledgement rissa an sneden dav ar aR tse eee aadedadenanaaehera AES 01 01 02 08 09 11 13 15 il e Map of layout of 70A 1169B dr Laser Control Curtain Divider Other Half of Room Laser door interlock Floor Plan Above is a floor plan of the laser lab Note that only western half of the room is shown e Decide which wavelength is to be used Refer to chart below on which units crystals are needed Wavelength 220 0 272 0nm Yes 56 Signal _ TETTE 345 1 365 9 nm None No No e Decide if the F
4. 0 54 F11 104 250V T O 1A F410 A 250V T O 1A FIIOAL2 5 0VIT 104A PUAIOA ZSOV IT 1 54 FISAOA 250V T OA Palo aA esoVveT 10A Feo ase soVert TA FefloaAfesoveT 1 04 Fa OAs250V T O 25A FIQMOA 250V T 10A F1e10Ar250WT 0 54 Falo 2S0vT O 1A FYAOALSOVIT 0 5A FisfloAfesovet 1 54 XXIX INSTRUMENTS Spectral Calibration Lamp mounted to MS125 Spectrograph using the 77251 Lamp Mount A diode array detector is on the output of the MS125 E Compact and simple tools for calibrating spectral instruments Narrow discrete UV to IR wavelengths Excellent stability Supported by mounting and fiber optic accessories for efficient coupling These Pencil Style mercury and rare gas sources are used for wavelength calibration of spectroscopic instruments such as monochromators spectrographs and spectral radiometers They produce narrow intense lines from the excitation of various rare gases and metal vapors We also offer a full range of accessories from mounts and holders to fiber optic adapters and aperture shields WHICH LAMP DO CHOOSE We offer six lamps choose the lamp or lamps which suit your wavelength range using Table 1 as a guide The single gas lamps Xe Ar Ne and Kr have distinct lines the Hg Ar and He Ne share the mercury lines but also have distinct differences Mercury Argon Lamp Preferred lamp for calibration using mercury line spectrum Temperature inse
5. 6SFO0098 Date Modified October 18 2003 by Samuel Chen XXXV XXXVI
6. 957 L K Bums K B Adams and J Longwell Interference measurements in the spectra of neon and natural mereury Opt Soc Am 40 339 344 1950 a January 1996 Vol 35 No 1 APPLIED OPTICS Above Calibration lines for Hg mercury lamp obtained from http www uvp com pdf wavelengths pdf XXXI Appendix 4 Getting Started Cheat Sheet Getting Started Before turning on the laser be sure to remove any metallic or reflective jewelry including watches rings and necklaces basically anything that could get in the path of the laser and reflect the beam Please record the number of shots on the flash lamp when you first power up the laser and when you are finished This should be recorded in the laser lab notebook with the average reading from the power meter the laser pulse and the maximum power the units are arbitrary Please remember to clean up after your self this includes appropriately taking care of any waste generated cleaning out cuvettes and removing all scratch and other unnecessary papers Ideally leave the lab cleaner than when you came in remembering however that this is a shared space and ask before removing or altering an item Laser Lab Reminders Setup 1 Turn on door interlock system 2 Check that No gas valve is on 3 Turn water valve to a 45 angle 4 Check that gas is flowing 0 4 0 6 scfh 5 Make sure that water is present in the reservoir on the side of the power supply is between the
7. Handbook for Operating a Spectra Physics Quanta Ray Pro Series Nd YAG laser and MOPO SL Master Oscillator Power Oscillator Utilizing WinSpec Samuel Weisheng Chen Chemical Science Division Ernesto Orlando Lawrence Berkeley National Laboratory Berkeley CA 94720 DISCLAIMER This document was prepared as an account of work sponsored by the United States Government While this document is believed to contain correct information neither the United States Government nor any agency thereof nor The Regents of the University of California nor any of their employees makes any warranty express or implied or assumes any legal responsibility for the accuracy completeness or usefulness of any information apparatus product or process disclosed or represents that its use would not infringe privately owned rights Reference herein to any specific commercial product process or service by its trade name trademark manufacturer or otherwise does not necessarily constitute or imply its endorsement recommendation or favoring by the United States Government or any agency thereof or The Regents of the University of California The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or The Regents of the University of California il Table of Contents Map of layout of room 70A 11O9B cece ccc cece cece eee eee eenenees Reference chart on
8. ck those to protect against intruders ex door interlock and those to protect the equipment ex cooling water interlock Average time it takes for a fluorescence to decay to its ground state Emission of light from any substance that occurs when an electron in the excited state relaxes to the ground state See phosphorescence and fluorescence Device used to diffract light and select a small portion of the wavelengths Master Oscillator Power Oscillator Neodymium Yttrium Aluminum Garnet A path for an electronically excited atom or molecule takes to return to the ground state without emitting a photon Type of luminescence In excited triplet states the electron in the excited orbital has the same spin as the second electron in the ground state orbital This is a forbidden transition so the emission rate is slow gt 1 millisecond Programmable Timing Generator See pulser An arbitrary unit of measurement of the laser s power Pulse can be adjusted by two knobs on the Nd YAG Pg 7 and be affected by warm up time age of flashlamps and temperature Pg 6 7 Used interchangeably with PTG A device used to control timing parameters of the CCD Pg 14 19 A decrease in fluorescence intensity Wide array of process that causes quenching Example when target molecule element binds with a nonfluorescent compound when the excited target molecule element is deactivated from colliding with another compound A path for an electronica
9. d and the values we present should be useful as wavelength standards at the level of 0 000 nm for instruments with resolving powers of less than 17 000 We thank available his spectrum measuring and spectrum analysis software for modifying it to better meet the needs of our ongoing Hg observations and for coming to the National Institute of Bruce Pulham for making Standards and Technology to install and test it on our computers References and Notes l J Reader C J Sansonetti and J M Bridges Irradiances of spectral lines in mercury pencil lamps Appl Opt 35 78 83 1996 2 Certain commercial products are identified in this paper to specify adequately the experimental procedure Such identification does not imply a recommendation or endorsement by the National Institute of Standards and Technology 3 A R Thorne C J Harris L Wynne Jones RC M Lemer and G Cox A Fourier transform spectrometer for the vacuum ultraviolet design and performance J Phys E 20 54 60 1987 4 V Kaufman Wavelengths energy levels and pressure shifts in mercury 198 Opt Soe Am 32 866 870 1962 5 R C M Learner and A R Thome Wavelength calibration of Fourier transform emission spectra with applications to Fe I J Opt Soc Am E 2045 2039 1988 6 J Blaise and H Chantrel Structures hyperfines de raies du spectre d are du mercure et moment quadrupolaire de Hg J Phys Radium 18 193 200 1
10. data immediately after the sample is excited However in solution water scatters the light and gives a broad spectrum which will compromise the data At O F 21 C and 1 atm the light scattering from water lasts about 60 ns This author usually sets the gate delay at 100 ns for routine single specie fluorescence spectra collection xxii Useful Hardware Tips for Data Optimization Since the laser beam has a finite width it is best to have the at least 1 5 mL of solution in a 1 cm pathlength cell Anything less than 1 5 mL has a probability that the full potential of the fluorescence signal is not exhibited The slit is used to control the amount of light entering the monochrometer and an attempt to make the light a point source Closing the slit increases the resolution how detailed precise the spectrum is but dramatically weakens the signal and increases the noise Opening the slit causes the peak width to increase and 1s used for a more accurate quantitative measurement ex complexation constants or concentration measurements sample Holder Box CANTOR Laser Ja Dre MMonochrameter Slit 1 5 nmimmj Figure 25 location of knob controlling the monochrometer The slit can be adjusted by a knob found between the black sample box and the monochrometer see Figure 25 Each clockwise revolution of the knob represents 250 um increase in slit width According to the manuals the dispersion is 1 7 nm mm The above sugg
11. e CCD located behind the Multi Function Optical Meter See Detector Floor Plan and Figure 16 i TH iNi j LARET coe 8 r MFg TAEA i n x i J 7 T j e iiir z q fj ef 4 5 rs h S E ke ae az T a ba i el oo Figure 16 Picture of the CCD The yellow circle highlights the location of the OFF ON switch Currently the camera is in the OFF position e Turn on PTG Pulser located underneath the table See Figure 17 WAN La Figure 17 Picture of the pulser The yellow circle indicates where the ON OFF switch is located on the pulser Currently the Pulser is in the OFF position NOTE Throughout this manual the word camera and CCD are used interchangeably xvii WinSpec e Open WinSpec located at Start gt Program Files gt Roper Scientific gt WinSpec32 e After approximately 15 seconds the following window should appear Figure 17 Camera Has Been Set To Safe Mode Select The Desired Action f Keep In Safe Mode Restore To Last Settings C Restore Defaults Figure 18 Menu seen upon opening WinSpec e If not exit WinSpec turn off the ST 133 Controller and turn it on again Open WinSpec again If this fails it is recommended to turn off all CCD related material CCD transformer and pulser and reboot the computer e Select the appropriate camera state There are 3 options for the camera state a Keep in Safe Mode b Restore to La
12. e optimized energy levels for Hg in a lamp with a pressure of 400 Pa 3 Torr Ar comparison the high resolution spectrum of the electrodeless lamp was degraded to a resolution of 1 0 cm l by convolution with a Gaussian as was done for the pencil lamps Again the pencil lamp wavelengths were found to be consistently shifted to the red in this case by an average of O 000S4 25 nm On the basis of the pressure shifts measured by Kaufman a shift of this size is too large to be explained by the Ar pressure in the pencil lamps The shift may be attributable to a higher pressure of He in the pencil lamps which operate at a significantly higher temperature than the electrodeless lamp In any event our present results represent the He wavelengths as emitted by the pencil lamps and should not be applied to other types of low pressure He lamps if an accuracy higher than O 001 nm is required We note that wavelengths emitted by the pencil lamps at different discharge currents or with ac excitation may differ slightly from obtained in this work We thus recommend that if these lamps are used in applications for which accuracies of better than 0 0005 nm are required our experimental conditions should be carefully reproduced those 6 Conclusion In summary we have made precise measurements of the Hg lines emitted from three Hg Ar pencil lamps With the exception of the 434 7 nm line the wavelengths are consistent for the three lamps observe
13. estions are not hard and fast rules but are a good rule of thumb estimate It is best to take spectrums at different slit width accumulation exposures gains and concentrations to optimize spectrum parameters xxiii Pulser Setup Sequential Mode One unique characteristic found within species that fluoresce are their lifetimes WiunSpec offers an automated lifetime collection which may be found under Setup gt Pulsers gt Setup Pulsers Under the Gating tab select the Sequential mode and click setup Below is the WinSpec Sequential Gating Setup box with a short description what the most commonly used features are Pulsers x Heart of TRLFS Can tell the CCD when to collect and the Mumber of Spectra will fill in the points between the stat and end delay Select Active Pulser C Pa200 DG535 es states how long the camera should be opened for after G PIG _Setup Pulser each shot Advisable to keep both start and end widths the same to acquire the same level of background PTG h Non ae Triggers Gating Aus Trig Out Sequential Gating Setup x Mode ate Delay From TO Out OF Repetitive Spectra il a i A icaidh aE h W Che P Sy Min Max MessSsDigplayed et Disp Increment Type PIRA lt i O ue Dely weenen O Booo 0 use Delay Increment Wise Fete E Setup Ae Sequential Burst Mode states number
14. he manual K z How many times the computer recieves Number of Spect fi D j data from the camera for one spectrum CCO Readou C Use Full Chip Use Region Of Intepee Oe OS ma TOA ADC Timing Process Main i arate fits Usually increasing the number of accumulations will decrease the noise level en Accumulations shutter mode is generally used when the spectrum does not require the use of a pulse laser but rather a continuous beam of light ex calibration with a Hg lamp Gate mode is used for any spectrum requiring the use of the laser ITRLF 5 fluorescence spectroscopy excitation spectroscopy etc j Tells WinSpec to use sated Parameters found under setup gt Pulsers Safe Mlode turns off the CCD Acts as a noise discriminator As the gain IS Increased the ability to differentiate peaks from noise is increased Its range Is any Integer from O to 255 Figure 22 Experimental Setup Menu XXi Pulser Setup Repetitive Mode if Wind pec 32 File Edit View Acquisition Calibration Tools Display Spectragraph Process eneee TT Figure 23 Location of Pulser Setup Pulsers X Select Active Pulser C P200 Dop Setup Pulser f PTG PTG None Triggers Gating An rig Dut Repetitive Sequential Burst Mode C OW i OFF Two modes are offered here repetitive and sequential Repetitive Mode is generally used for taking just one spectrum ora
15. lly excited atom or molecule takes to return to the ground state by emitting a photon The degree one 1s able to differentiate two peaks See Dispersion Standard cubic feet per hour Measurement of flow rate at 1 atmosphere pressure and 25 C Number of times the laser has fired xxvii Signal Wavelength Simmer Slit Width Spectrum TRLFS After the Nd Y AG beam passes through the BBO two beams of different wavelengths are seen The beam with the longer wavelength is the Idler Wavelength and the beam with the shorter wavelength is the Signal Wavelength The summation of the energy of the two beams equals the energy of the Nd YAG Refers to the flashlamps being in a charged but idle state How wide the slit is on the monochrometer The smaller the slit the better peaks can be resolved but the nosier the spectrum gets Pg 20 A representation usually graphical of characteristics Time Resolved Laser Fluorescence Spectroscopy Technique used to determine number of species present by discovering how many different lifetimes are present XXVIII Appendix 2 Laser Power Supply Fuse Positions Note just the board for the location of the fuses is shown no other laser components are diagramed The values in bold represent the Ampere value of the fuse in the location Shot counter up here Power supply front Eey Switch on this end FaNOAfes0VeT 10A PSO AfesoveT O 25A FISMOA 250V T O 5A FaloaAfesoveT
16. lues based on irradiance values from Ref with the intensity of 436 nm set arbitrarily to 10 000 The wavelength uncertainty is 0 0001 nm with the exception of that of the 434 7506 nm line see text 5 Discussion Precise wavelength measurements for natural Hg have previously been reported by Burns ef al Comparison of our results with the earlier values shows significant deviations All lines from the pencil lamps are shifted to the red by an average of O O0068 32 nm with respect to the Fabry Perot measurements by Burns ef al It is not clear whether this shilt represents a real difference between the pencil lamps and the positive column source used in Ref 7 or whether it is a result of measurement of weakly exposed partially resolved line profiles by Burns ef al We have also compared the pencil lamp results with our measurements of the Hg lines in the natural He electrodeless discharge lamp For this Table 3 Comparison of 198Hg Wavelengths Derived from Our High Resolution Fourier Transform Spectrum of a Natural Mg Electrodeless Lamp with the Results Obtained by Kaufman Vacuum Wavelength nmi Deviation This Study Kaufman inm S462 27060 546227063 0 000003 407 898902 407 895940 0 000038 404771464 404 771469 0 000005 435 975297 435 975257 0 000030 Ref 4 Derived from the fully resolved hyperfine structure components of Ho by use of intervals measured by Blaise and Chantrel Calculated from th
17. menu Laser will ramp up oscillator and amplifier BEAM LOK and D LOK are checked If everything is OK the laser will operate PULSE should be around 1000 units upper bar scale under optimal conditions new lamps Expect the maximum PULSE to be between 880 1000 units See Figure 10 SWITCH OFF Figure 10 Picture of a normally operating Nd Y AG Controller Notice that the PULSE is 876 far below the optimum 1000 units 12 Let laser run for additional 10 15 min This is for warming up the FDO and MOPO crystals 1X 13 Open the Harmonic Generator HG lid on the side of the Nd YAG Laser emission at 534 nm UV Visible eye protection Turn upper screw very careful only a few um with the pulse reading in sight and optimize pulse Then turn the lower screw and optimize This is to optimize the laser s FDO position so the maximum power leaving the Nd YAG is achieved Note Lower screw is more sensitive than upper screw There is a slight time delay from turning the screws and the pulse reading on the Beamlock Controller See Floor Plan on pg and Figure 11 Figure 11 Left picture shows the location of the hatch containing the Harmonic Generator HG Right shows the location of the screws upon opening the hatch MOPO e From Page 1 decide if running with or without FDO Ifthe FDO needs to be used place the prism unit inside the MOPO in the beam path label prism active If the FDO 1
18. most used setups menus are Experimental Setup and Pulser setup Experimental Setup Experimental Setup is located under Acquisitions gt Experimental setup see Figure 21 Experimental Setup dictates how the computer collects data from the CCD See Figure 22 This differs from Pulser Setup which is responsible for how the CCD collects the data See Figure 24 Specifically the Pulser Setup controls the timing issues y Winspecfs32 File Edit View Acquisition Calibration Tools Display Spectrograph Process Setup windows Experiment Setup YT Setup F i na yr cate suta fiare Gan Acquire em Setur HODE HODE f HODE OPTS E Focus Video Focus Hardware LUT Exposure Intensity Easy Bin Step and Glue Readout Time Acquire B ackground Acquire Flat Field Video Pulse Counter Stop Acquisition Start Storage Figure 21 Location of Experimental Setup the menu to access Accumulations Gain and number of spectra XX This option is only available when Shutter Mode is engaged It controls how long the camera should stay open Experiment Setup wwe i Tells how many repeated runs are in the Save Load acquisitian For most experiments this would be Data Corrections set at one TRLFS will require more and is controlled at the Sequential Gating Setup noted under Time Resolved Laser Fluorescence l Spectroscopy TRLFS later in t
19. nsitive Average intensity is constant and reproducible Longer life Prefered lamp for calibration using Mercury line spectrum The 6035 Hg Ar lamp is insensitive to temperature It requires a two minute warm up for the mercury vapor to dominate the discharge then 30 minutes for complete stabilization The average intensity is remarkably constant and reproducible after the thermal conditions stabilize Mercury Neon Lamp e Emits additional lines in the VIS NIR Temperature dependent The 6034 Hg Ne Lamp is temperature dependent When run in normal lab ambient the output is very similar to that of the Hg Ar lamp that is the characteristic mercury line spectrum Forced air cooling i e from a muffin fan of the lamp adds the neon lines to the output This spectrum has a large number of useful calibration lines in the longer VIS and NIR regions see Table 1 PENCIL STYLE SPECTRAL CALIBRATION LAMPS Appendix 3 Spectral Calibration Lines for Selected Lamps PAGE 1 of 5 Table 1 Usable Wavelengths of Spectral Calibration Lamps Lamp Type Model No Lamp Type Modei No i 6035 6034 6033 6030 6032 6031 184 9 253 65 427 4 187 1 296 73 432 0 194 2 302 15 435 5 253 65 312 57 457 7 265 4 313 15 461 9 284 8 313 18 i 465 9 302 2 365 02 473 9 312 571 404 66 476 6 313 1511 435 84 483 2 313 181 546 07 557 0 320 8 576 96 587 1 326 4 579 07 758 74 345 2 614 31 760 15 365 02 638 30 769 45
20. of spectra collected for this run Directly affects the Delay and Width Increment Indication of the increments between eee spectra in the sequential spectra Advisable to keep the increments at a easy to remember value Tin Exponential ex 10 ns 50 us etc An Width and Delay Increment of zero suggests he Number of Spectra is set at one Change it if necessary Cancel Cancel View Width 7 Delay sequence I Save Sequence Values To File Setup File n CC Accumulations Software Accumulation Repeat width Delay for fi 2 Exposure s Cancel Gates Per Exposure 100 at eal Figure 26 Picture of Pulser setup in Sequential Mode generally used for TRLFS How many shots should the CCD collect before sending the data to WinSpec High exposures are recommended for low intensity fluorescence Help Note Be sure to reset the Number of Spectra in the Experimental Section see Fig 22 to one 1 if you revert from TRLFS to a fluorescence spectrum Ex If you do a TRLFS for 24 spectra which you typed 24 in the Number of Spectra in the Sequential Gating Setup see Figure 26 then decide to do a single fluorescence spectrum be sure to reset the Number of Spectra in the Experimental Setup back to one see Figure 22 Otherwise when acquiring for the single fluorescence spectrum you will be running it for 24 spectra instead of one XX1V Calibration Depending on the s
21. operates at 1068 and 534nm Beam energy SOMW S Average power 30mW xxXx1il References Oriel Instruments Pencil Style Spectral Calibration Lamps Oriel Instruments part of Spectra Physics http www oriel com netcat V olumellI pdfs v39pen pdf Roper Scientific WinSpec Princeton Instruments Spectroscopic Software User Manual Version 2 5A Roper Scientific January 5 2001 Roper Scientific PTG Programmable Timing Generator Operation Manual User Manual Version I Revision C Roper Scientific October 27 1999 Sansonetti Salit Reader Wavelengths of spectral lines in mercury pencil lamp Applied Optics January 1996 http www uvp com pdf wavelengths pdf Spectra Physics Quanta Ray MOPO SL Optical Parametric Oscillator User s Manual Spectra Physics Part Number 0000 263A Revision C February 2000 Spectra Physics FDO 900 Frequency Doubler Option User s Manual Spectra Physics Part Number 0000 244A January 1996 Spectra Physics Quanta Ray Pro Serier Pulsed Nd YAG Lasers User s Manual Spectra Physics Part Number 0000 257A Revision A January 1999 XXXIV Acknowledgements I would like to thank Professor Heino Nitsche Sarah Herbison Yung Jin Joey Hu Richard Wilson Phil Wilks and Dianna Jacobs for their help and critique This work was supported by the Director Office of Science Office of Basic Energy Sciences of the U S Department of Energy under Contract No DE AC03 76SF00098 7
22. ot saved If change of wavelength is necessary press ABORT momentarily to leave returning settings to table value xili No FDO Signal or Idler at fixed wavelength l Physically place the prism into the Prism Park position See Figure 12 This is because the prism physically blocks the Signal regimes beam path Note It is best to have Nd Y AG laser off before removing the FDO unit Otherwise putting the laser under RUN LP should be sufficient as long as laser safety goggles are worn at 1068 nm In the monitor menu select MOPO TRACK Press the OPERATE button to OPERATE 2 menu Switch to either MODE SIGNAL or MODE IDLER depending of frequency you want to look at refer to table on pg 1 Choose a START and END wavelength below and above the target wavelength respectively Input a range where the desired wavelength falls in between To move the cursor press either the BEGIN or END button momentarily Use the up down buttons at far right to change the numbers Press OPERATE button to OPERATE 1 This menu allows you to set the target wavelength Select wavelength with GOTO menu button Move the cursor by momentarily pressing the GOTO button Use the up and down buttons at far right to change the numbers Press and hold until beeps to set Press SCAN SETUP twice to SETUP 2 menu This menu will allow you to maximize
23. pectrum range different calibration lamp should be use Refer to the WinSpec manual offers an excellent treatise in calibration XXV Shut down l Press RUN LP hold until beeps in menu wait 5 10 min This is critical for the crystals Press Q SWITCH OFF press LAMP OFF wait 10 15 min until cooling water output is cold Press POWER OFF Switch off Nd Y AG and MOPO controller backside Turn key on laser power supply to off Leave switch below key always on to heat the crystals Turn off water and interlock Let the Nitrogen purge continue for 24 hours before turning off Note Essentially this is the reverse of the Start Up procedure described in the beginning of the manual Never block the Nd YAG laser beam manually with shutter paper When beam hit RUN LP to shut off laser beam and press RUN NORM to start beam XXVI Appendix 1 Glossary Accumulations BBO Camera Charged Coupling Device CCD Dispersion Exposures FDO Flashlamps Fluorescence Gain Gate Delay Gate Width Gates Per Exposures Gratings Half life Idler Wavelength Interlock Lifetime Luminescence Monochrometer MOPO Nd YAG Non Radiative Transitions Phosphorescence PTG Pulse Pulser Quenching Radiative Transitions Resolution scfh Shots How many times the computer receives data from the CCD for one spectrum Generally increasing the accumulations gives a smoo
24. peed of scan No of shots for each to be performed wavelength Wavelength tobe p rformed wavelength Select 0 shots for continuous scan Figure 13 Menu that should appear on the MOPO controller after executing Step 2 4 Press OPERATE button to OPERATE 1 This menu allows you to set the target wavelength xii 5 Select wavelength with GOTO menu button Move the cursor by momentarily pressing the GOTO button Use the up and down buttons at far right to change the numbers Press and hold until beeps to set Press SCAN SETUP twice to SETUP 2 menu This menu will allow you to maximize the power output of the MOPO at the target wavelength See Step 8 for details You also need to choose the device See Figure 14 500 0000 1220 614nm Figure 14 Menu that should appear on the MOPO controller after executing Step 5 8 10 11 Press DEVICE MO CRYS and use the up down keys until the 56 CRYSTAL signal doubler or 36 CRYSTAL idler doubler until beeps See Figure 14 Refer to the chart on Pg 1 if necessary Select and press METHOD MANUAL again until beeps Note Selecting any other mode other than METHOD MANUAL will erase tables stored in MOPO controller New menu appears Output number a representation of power can be maximized with arrows up and down at right side of the MOPO controller This manual setting is temporary and is n
25. requency Doubling Option FDO is to be used If not physically remove the FDO from the laser Nd YAG laser 1 Switch door interlock ON by depressing the red ON button See Floor Plan on pg and Figure 1 Figure 1 Door Interlock Panel 2 Open the nitrogen gas supply blue valve and wheel on gauge labeled GCR DCR Wex at right side of the door This is usually left open for convenience See Floor Plan onpg and Figure 2 Blue valve for nitrogen supply Figure 2 Location of blue valve for nitrogen supply valve Usually this valve is left open for convenience 3 Open the black valve at nitrogen distribution fixed to copper tubing for water inflow above backside of optical table If valve is parallel to the ground nitrogen valve is closed If valve is perpendicular to the ground pointed to ON valve is on This is usually left open for convenience See Floor Plan on pg 1 and Figure 3 4 Open the yellow water valve under optical table valve with pipe marked IN to a 45 60 angle The water serves as a cooling mechanism The outgoing valve shall be left open at all times See Floor Plan on pg 1 and Figure 3 Figure 3 Left shows the relative positions of the nitrogen and water valves Upper right shows what the nitrogen valve looks like in the OFF position Lower right shows what the water valve looks like in the OFF position Note that the valve in
26. s not to be used physically remove the unit See Figure 12 Refer to the MOPO SL manual for more instructions When working on the prism switch Nd Y AG to Run LP or better yet OFF Eye protection at 1068 nm EIEI Eig MOPO oe cover gt Bibi Nd TE a a Where the prism should be parked when not in use ere the prism TE be placed for the FDO to be active Notice the Figure 12 Shows location of prism that activates the FDO crystal Note the two parking position of the prism Xi With FDO at fixed wavelength 1 Inside the MOPO physically place the prism into the Prism Active position See Figure 12 Note It 1s best to have Nd Y AG laser off before removing the FDO unit Otherwise putting the laser under RUN LP should be sufficient as long as laser safety goggles are worn at 1068 nm 2 On the MOPO controller press SCAN SETUP button to SETUP 1 This menu enables you to choose the range in which the target wavelength falls 3 Choose a START and END wavelength below and above the target wavelength respectively Input a range where the desired wavelength falls in between To move the cursor press either the BEGIN or END button momentarily Use the up down buttons at far right to change the numbers See Figure 13 Select SCAN SETUP mode FOO wavelength Signal or Idler output 7 r i ii No of scans Scan starting Sean ending S
27. several spectra using only one set of timing parameters for the CCD i e Gate Width Gate Delay Exposures sequential Mode is used for taking a spectrum at different time delays after the laser excited the sample This mode will be dealt with Under Life time Resolution of this manual sates Per Exposure Exposures lets the CCD know how many laser shots should it collect before sending that data i e one accumulation in a spectrum to VWinSpec Increasing the exposures is useful for detecting weak signals becuase more light is allawed to strike the CCD surface allowing more charge to accumulate on the transistors so a signal could be Seer Figure 24 Picture of Pulser setup in Repetitive Mode L CON OFF Setup windows Hardware Detector Temperature Environment Custom Toolbar Preferences Load Factory Defaults Diagnostics Gate Width tells the CCD how long the CCO should be opened for In fluorescence spectroscopy too short of a gate width shows a weak peak signal because not enough light was picked up Too long of a gate width compromises the data because towards the end of the gate width more noise is collected than signal since the signal decays with time Bracket Pulsing Gates Per Exposure m 100 i Exposure s Help sate Delay tells the CCD when to begin collecting data In fluorescence spectroscopy one would ideally begin collecting
28. st Settings C Restore Defaults When in doubt keep the camera in Safe Mode This turns off the CCD and prevents any strong light from damaging the CCD Restore to Last Settings is used 1f the settings calibration accumulations gain exposures etc are identical to before xviii e Before any optimization can begin the fluorescence spectrum must be centered This can be done by going to Spectrograph gt Move See Figure 19 yi Winhpec t2 File Edit View Acquisition Calibration Tools Display Spectrograph Process Setup Window SCRA Define dt jE atli Hak Calibrate S HEE J 2 GATE f SHTA SAFE GAIN HODGE Aone ADE OPTS Figure 19 Location of moving the grating to center fluorescence spectrum e The following screen should appear Select the appropriate grating the center wavelength Hove Spectrograph Gratings Mirrors Acton SP500 on COM Grating 200 BL 500 nm Move to p nm Speed f OU rrr reir cared Heb Figure 20 Picture of the Move Spectrograph Grating tells you how large the window is 300 BLZ 90 nm on either side of the center Total window length is 180 nm 600 BLZ 44 nm on either side of the center Total window length is 88 nm 1200 BLZ 20 nm on either side of the center Total window length is 40 nm X1X Setups WinSpec offers flexibility when determining the quality of the data collection Two of the
29. the power output of the MOPO at the target wavelength See Step 8 for details You also need to choose the device Press MO CRYSTAL until beeps X1V 9 Select and press METHOD MANUAL again until beeps Note Selecting any other mode other than METHOD MANUAL will erase tables stored in MOPO controller 10 New menu appears Output number a representation of power can be maximized with arrows up and down at right side of the MOPO controller This manual setting is temporary and is not saved If change of wavelength is necessary press ABORT momentarily to leave returning settings to table value Notes on Operation There is an inherent problem with the MOPO in that its energy fluctuates between laser shots and the maximum energy decreases over time To correct this we have installed an energy meter The energy meter is used to determine the exact amount of energy per laser shot This especially useful if the laser 1s going to be used over longer periods of time when laser power 1s inconsistent XV Turning on the CCD Camera Detector Floor Plan Sample Holder ta a iT z a E O oO a Transformer e Turn on following 3 devices in no particular order e Turn on the transformer located about 50 cm left of the black sample holder box See Detector Floor Plan and Figure 15 Figure 15 Picture of the transformer Currently in the ON position XVI e Turn on th
30. ther spectrum Pg 17 18 Beta Barium Borate A nonlinear crystal where by changing the angle the the resulting wavelengths change See CCD Used interchangeably with camera in this manual A device which accumulates charge on its surface proportional to the amount of light striking it Excellent for high quality low noise spectra Measures ability of monochrometer of resolving two peaks Lets the CCD know how many laser shots should be collected before sending the data to the computer as one accumulation Pg 19 Frequency Doubling Option Allows the MOPO to operate in the 220 440 nm region It literally doubles the Nd YAG frequency from 534 nm to 267 nm Pg 1 8 12 In a laser the lamp which flashes to excite the lasing medium Type of luminescence In excited singlet states the electron in the excited orbital has the opposite spin of the second electron in the ground state orbital which is a spin allowed transition and the emission rate is fast lt 1 microsecond Acts as a noise discriminator Tells the CCD when to begin collecting after a laser shot has passed through the sample Pg 19 21 How long should the camera be opened for each shot Pg 19 21 See Exposures Number of diffraction lines per Time it takes for a fluorescence to decay to half of its intensity See Signal Wavelength Fail safe pieces of hardware designed to disable the Nd Y AG system should any of the pieces be defeated Two general types of interlo
31. two level markers during operation 6 Turn on laser key 7 Turn on MOPO and Nd YAG box 8 Press the Nd YAG POWER ON in the front LET THEM WARM UP FOR 10 15 minutes 9 Press RUN LP and LET IT WARM UP FOR 20 30 min 10 Press RUN NORMAL 11 Adjust the crystal in the laser system Pulse maximum will be somewhere near 880 1000 Wear laser goggles at 534 nm 12 LET Nd YAG WARM UP FOR 30 min 13 On the MOPO controller under SETUP 1 enter the BEGIN and END wavelength that will bracket the target wavelength ex if the target wavelength is 410 nm an appropriate start and end points are 380 and 420 nm respectively 14 Under OPERATE 1 enter the desired GOTO point 15 Under SETUP 2 choose the appropriate crystal to change look at chart in the FDO manual to determine which device is appropriate under the target wavelength press and hold Then press and hold METHOD MANUAL Change the up and down button to maximize the power 13 000 14 000 XXXll Reminders When using the laser be sure to save your data and write down all information pertaining to the laser itself and the parameters set for that run including 1 Slit width 2 of accumulations 3 gain 4 delay 5 exposure 6 width 7 center wavelength of spectrum and the grating number in BLZ Also be sure to write down what the file name is there are a lot of files on the computer and it makes data analysis simpler The Nd YAG laser
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