Camera Use With M2DU Stage
Contents
1. z position in mm in the moving stage 3 Parts List WinCamD U series head The recommended default camera is the WinCamD UCD12 M2DU WC XXX XXX system comprising the following options Standard System Options e g M2DU WC 250 NIR Lens focal length options Wavelength options 75 100 mm focal length 22 mm aperture 100 100 mm focal length M2DU WC 22 mm aperture 150 150 mm focal length UV Fused silica singlet for 250 450 nm Comprising 22 mm aperture USB 2 0 M2DU Stage 2 5 um steps 44 mm travel 3 m flexible cable Lens mount bracket Mounted lens Power brick VIS Achromat for 400 800 nm 150 50 150 mm focal length 47 mm aperture NIR Achromat for 630 1100 nm 250 250 mm focal length TEL Achromat for 1000 1800 nm 22 mm aperture 250 50 250 mm focal length 47 mm aperture 500 50 500 mm focal length 47 mm aperture 4 Getting Started Short of time Save yourself time by carefully following through this User Manual the first time that you use the equipment Once you have done it properly once the next time will be simple and fast This User Guide assumes that the WinCamD system is installed has been run with the Version 6 00R12i or higher software in the PC you are to use is working in your PC and that you have already learned how to use the WinCamD in standard operation on beams from this laser If this is not the case first install the software install and run the WinCamD and understand its operat2. Beam dependent Absolute accuracy better than 5 is possible but can be difficult If your beam M is actually 1 03 the value that you see may vary from 0 98 to 1 08 If it is less than 1 0 it will show in orange as 0 98 but this does not necessarily mean that it is a bad result 2Wo_u v the beamwaist diameters Zo_u v the beamwaist positions with respect to the principal plane of the lens Zr_u v the beams Rayleigh range Theta_u v and NA_u v the far field divergence of the focused beam in mrad and as NA M Squared Dialog Output Beam Results Wavelength 632 nm Black X axis eee uv 43igma Waist Astigmatism Total span 46 6 mm Waist Assymetry Current Z location 42 5 mm Div Asymmetry Decrement Sample Auto mode Increment Sample gt gt Show SD view Use clip widths at O and 90 deg Use major minor widths Setup Me Save Mz Export Data Start he Auto M2 Setup Recall Me Close M2 Dialog M Squared Dialog Output Beam Results fx M 2 u 1 05 M42 v 1 03 2Wou 65 6 um 2Wo_v 65 8 um 14 58 mm Zov 14 20 mm Theta v 12 7 mr NA Y 0 006 Set full range Wavelength 632 nm Black axis Cliplevel uy f 45igma Waist Astigmatism 0 032 Total span 21 9 mm WaistAssymetry 6 657 Current Z location 0 1 mm Div Asymmetry 1 037 lt Decrement Sample Manual mode Increment Sample gt gt Show 3D view Use clip widths at O and 90 deg C Use m
3. camera at the focus If so add as required before proceeding An additional ND2 0 filter is provided with the M2DU Chapter 5 of the WinCamD manual describes attenuation and sampling solutions DataRay offers additional ND filters variable ND filters wedge samplers amp holographic beam samplers to assist you Verify the lens incident power with a power meter 8 Start the Software Start the software Click the M2 button A series of warnings advise that the software will in turn e Set the Clip a level to 4sigma e Set Full resolution e Turn off the filter e Force the crosshairs to zero degrees Accept all the offerings by clicking OK You will then see the Rueuitbiuetadts WinCam M squared Setup box Wavelength in nm a Enter Wavelength in nm and Lens Focal Length 632 8 nm b LPPSO If you require that the software calculate the LPPSO see User Guide source beam characteristics you need to measure a critical EOS mm distance Lens Focal Length in mm 85 0 mm The flexible lens focal length wavelength amp spacer options means that lens Principal Plane to scan stage position is not fixed and must be entered 2o Delta from table in User Guide Use a mm scale tape to measure LD the distance from the 5 70 mm front of the lens flange with dust cap removed to the back of Translation stage maximum travel if manual the Lens Mount Bracket the red double arrow labeled LD on 440mm the diagram two pages ea
4. Ed Inclusion Shape Inclusion region ENABLED C Rectangular Square Lock current inclusion region Inclusion region shape is round Inclusion region shape is elliptical Set Clockwise Orientation of Major 0 is Horiz Inclusion r gion shape is square In Degrees lo a Inclusion region shape is rectangular 7 w Define inclusion region shape size and orientation f Elliptical Circular Dimensions Major asie microns Click Define inclusion region shape size and orientation and set up Elliptical Circular and the Automation section as shown right You may ignore the other boxes in the dialog Minor asis microns r Automation W Auto Orient 7 W Width Clip a diameter times 3 00 Refresh Cancel 12 Perform a Coarse Scan Press Auto M2 Setup to perform a coarse scan of 20 equally spaced points in z using the full length of the stage with an Average of 2 images per z position Orange Data During the scan through a beamwaist the software changes the Exposure to accommodate the change in the irradiance as the beam diameter changes During Exposure iteration before the correct Exposure is determined the Peak will sometimes go to 100 and the numbers will turn Orange to warn of this saturation Do not worry The software only uses data taken when the exposure has stabilized and the Peak is below 100 At the conclu
5. Though this statement is slightly ambiguous we interpret within one Rayleigh length as lt zR and beyond two Rayleigh lengths as gt 2 ZR For equispaced samples in z and an initially unknown beam waist position these sample position requirements of the standard are met by a minimum of 18 samples at zR 3 intervals about the waist e g from 3 ZR to 2 67ZR To ensure that we spatially sample the actual beamwaist diameter within 1 requires the z samples around the beamwaist to be spaced at zR 3 5 intervals For equispaced samples the samples in the zR to 2 zR region are superfluous to the specific requirements of the Standard but may still be used in the calculation The beam diameter equals 2Wo at the beam waist 1 greater 2 02Wo at 0 14zZR 2 greater 2 04Wo at 0 20ZR x 1 414 greater 2 83Wo at zR Rayleigh Ranges or length x 2 236 greater 4 47Wo at 2ZR x 2 692 greater 5 38Wo at 2 5zR x 3 162 greater 6 32Wo at 3ZR ISO 11146 requirements can also be met by more samples at a higher sampling frequency in ZR A least squares hyperbolic fit to the data Notes a With a beam profile that is a pure Gaussian the Variance Second moment definition is exactly the same as selecting a 13 5 Clip Level but if your beam is non Gaussian which is most beams the Variance method is more consistent An exception to this general rule is that the presence of a significant background level abov
6. front of the lens c Rotating about the front lens cap center as pivot point adjust the laser or the rear of the M2DU to center the laser beam on the camera target d Lock down the laser and the M2DU stage e Remove the lens amp camera covers Open amp Start the software f Verify that Peak ADC is lt 90 If not revisit Sec 4 10 Set the Capture Block Se is In order to minimize the size of saved M2 files it is recommended that you minimize the Capture Block If you ignore this advice your default M file size will be 135 MB and your hard drive fill rapidly Capture Resolution f FULL 4 65 4 65 microns t FAST 9 390 9 30 microns Capture Block camera pixels C 32432 C 64x64 By contrast a 256 x 256 Capture Block f 128x128 fe 256 x 256 reduces file size to 8 MB 384 x 384 512x512 752 x 752 C 1024 x 1024 Press Alt S to open the Capture Setup box 1200 x 1024 In the M Squared Dialog box click at the m Custom 128 w 112847 Flip image vertical Rotate 180 deg he Frohle sith baseline s ihetranhan If the image moves more than 25 of the screen readjust your beam alignment until it moves less than this With the stage at the lens end select a Capture Block around five times the visible beam size In most cases 256 x 256 should suffice extreme ends of the gray scale and watch the image in the Capture Setup box For CW lasers Auto exposure sets correct exposure for all z values 11
7. AN Data Ray Inc User Guide seen eipalivered as Solution WinCamD M2DU M system Applies to Software Ver 6 00S6St or higher running under Windows XP with SP2 or higher or Windows Vista Very Important With full Administrator Rights Install Open and Close the latest Software before connecting the Camera or the Stage Windows Vista See link at website Short of time Save yourself time by carefully following this User Guide the first time Done properly once the next time will be simple and fast Once done for future convenience so you need only look at page 1 copy your lens setup details from page 7 Lens focal length LD User measured A Zo Delta LPPSO Enter in M2 dialog Zo Delta Enter in M2 dialog See diagram pages 8 See diagram page 8 Lens Principal Plane to Sensor at O Front of lens mount to Principal Plane Applications M Squared Dialog Source Beam Results Ed M measurement of CW amp pulsed lasers Miz u 1 05 Miz 1 03 M measurement of focused beams nio u 570 0 um 2Wo o v 587 3 um Focus position of laser assemblies Zo u 869 69 mm Zo V 882 36 mm Zr_u 384 71 mm zry 411 04 mm Features Theta u 1 5 mr Theta 1 4 mr ASR Auto Scan Range for ISO compliant scan NA u 0 004 NA v 0 004 USB 2 0 for field service applications Fast Compact Portable system LxWxH 8 x 2 9 x 4 3 200 x 109 x 74 mm Total weight 4 Ib 1 8 kg View Output Set full range Field replacea
8. Check Exposure amp optionally subtract residual noise Check Exposure Move the stage in z by clicking on the scale until the beam diameter is at or close to minimum CW beams Adjust any attenuation sampling until the Peak ADC is lt 95 and that at the beamwaist 0 25 ms lt Exposure time lt 20 ms If it is not revisit Section 4 above Pulsed laser beams Currently the software averages multiple pulses and varying the Exposure time effectively varies the number of pulses averaged The minimum PRR for which the system will work reliably in default mode is around 1000 Hz Ensure that at the beamwaist both 0 2 ms lt amp 10 000 PRR ms lt Exposure time lt 20 ms A later release may extend these limits Setting the maximum exposure limit to 1 000 ms instead of 200 ms can extend the upper exposure limit to 200 ms but the increase in dark current spikes will affect the M accuracy Optional and not normally necessary Subtract residual electronic noise With the stage close to the focus e Right click the Exposure time slider and uncheck Enable auto exposure adjustment e Set Average to Average 10 e Block the beam and allow 210 frames to average e Click on the background subtraction button Click OK e Recheck Enable auto exposure adjustment Optional and not normally necessary Enable Inclusion Region n p i Right click on the 2D image area to open a box with several options Inclusion Shape Size and Orientation
9. a 74 um 2Wo v 75 um Clip b 50 0 38086 um Zo v 37705 um 6830 um 11 5 mr Theta_v 11 3 mr 2Wi Major 74 um 0 006 NA v 0 006 2W_Minor 73 um you forget to do so a 2W_Mean 73 um Setfulrange warning will appear before Eff diam 76 um you start another M2 scan Etlipticity 0 98 Orientation 17 8 deg Crosshair 0 0 deg eee omen e om Sample and Increment Yc 390 um Wavelength 632 nm Black X axis Sample gt gt scan through f Clipievel uv 4Sigma Peak 86 1 measuremen ts E lt lt Decrement Sample Manual mode Saved fi les conta i n the 2Wua 4Sigma 74 um Show 3D view Use clip widths at O and 90 deg Use major minor widths may switch between Use clip widths at 0 and 90 deg and Use T original images so you ITTA ITTE MCD Recall M2 Setup M2 Start M2 E major minor widths Scale 75 0 umjdiv Peak 85 9 B 1 1 Scale 75 0 umjdiv Peak 85 0 B 1 1 Ready When Use major minor widths is selected Use ISO 11146 compliant diameters and angles is automatically selected and any clip level is ignored If the beamwaist profile in the propagation direction the z direction is either too flat or too V shaped the fit will be poor Click on Show 3D view to see the visually more satisfying 3D view shown right Click on Export Data to export the data to an M2data txt file in Notepad which may be saved for subsequent analysis
10. a diameter as the measured beam 0 Where 2Wo The second moment 40 beam waist diameter The shape of the M curve may be shown to be hyperbolic of the form Where Zp is the Rayleigh Range defined as the distance at which the beam diameter is V2 5 greater than the diameter at the waist zg may be shown to be 2 2W0 m o A definition of M in terms of a measured diameter is Me Z jew Specifications l Max Input beam p at max Mag s F at profiler res limit Max beam diams See graph right 25 i E 100 mm standard lens 400 to 800 nm with standard lens E E 20 150 mm lens option 260 to 1150 nm with optional lenses g 250 mm lens option amp To 1350 nm on high power beams with O 15 500 mm lens option optional lenses E M Range 1 to gt 50 10 Q M Accuracy 5 typical 5 x lt M Repeatability 2 typical Ss 0 Beam dependent Achieving absolute accuracy better than 5 is possible but can be difficult 200 400 600 800 1000 1200 1400 1600 1800 Wavelength nm 2 Beam Modeling for Lens Selection An intuitive Excel spreadsheet simplifies lens selection Some customers will have already received this spreadsheet during the purchase process If not download http www dataray com files Lens choice for M2 measurement xls from the User Manuals section at the website and model your beam in
11. ajor minor widths Setup M2 Export Data Start M2 Recall M2 Close M2 Dialog mm 14 Source Beam Characteristics M Squared Dialog Source Beam Results Press the View Source button below the dialog to toggle between the Output beam and the source beam The software uses Gaussian beam calculations to calculate the position and dimensions of the source 7r u 384 71 mm e onee ne curve see previous page are Tnetau 15mr Tnetav 1 4 mr_ calculations of Theta u 1 5 mr Theta 1 4 mr NA u 0 001 NA 0 001 Waist Astigmatism s_v s_u s_u s_v 2 the difference between the calculated source waist Zo distances from the lens principal plane divided by the average Zo distance Waist Asymmetry 2Wo_u 2Wo_v the ratio of the calculated source diameters Divergence Asymmetry Theta_u Theta_v the ratio of the calculated source divergence angles Important The source Zo_u Zo_v values are given as measured from the front of the lens holder not from the lens principal plane This is because this is a distance you can easily measure For this particular beam Zo was 860 5 mm so the estimates are accurate to a surprisingly good few 15 Save the Data Press Save M2 to save the BtnnAURMULAR clCRUOMCl MVOC OMe eae em SOM Ree mem RUS RCTS MTOM Ue cee ais Tot ot Seem el CE results as a wef file If M Squared Dialog t 7 SW Xxxx F001 SSE OW XY 2 Delta 432 1 um Pixel 11956 18 29 4xSigmaf
12. and from which the data may be exported into Excel P M2data txt Notepad File Edit Format View Help Wavelength 632 nm Cliplevel u 435igma Waist Astigm Total span 21 9 mm Waist Assymetry M Squared data file for wincamb Date Current Z location 9 9mm Div Asymmetry T wavelength 632 nm Cliplevel uy 45 7qma Total span 34 3 mm 280 626 ow e a 649 ow ef4 4a5 ow 269 503 ow 263 4445 ow 2537 164 ow 242 460 ow 246 455 ow 243 805 ow 238 641 EW 234 034 EW 220 380 2 wy 220 645 2 why 216 244 EW 210 786 EW 205 5346 EW Sample 1 2wu Sample 2 2wu Sample 3 2Wwu Sample 4 2wu Sample 5 2wu Sample 6 2wu Sample 7 2wu sample 8 2wu Sample 9 2wu sample 10 2wu sample 11 2wu sample 12 2wu sample 13 2wu sample 14 2wu sample 15 2wu sample 16 2wu Click on Recall M2 to browse for and open previously saved files 16 Second time around When the software is closed it saves the current settings If the laser power and alignment have not changed substantially all you need to do is rerun the software If anything has changed revisit that section only 17 Support If you get an error message press Alt Prt Sc to put it to the clipboard and then Ctrl V to put it into an email message Sometimes these are diagnostic warnings rather than something more significant and clicking the OK button allows you to proceed If you get a result which mak
13. are provided by DataRay when the longer focal length lens is provided with the system Optionally but recommended use the lower slot in the Lens mounting bracket to bolt the whole assembly to an optical table or other rigid mount Connect the 12 V DRPSU 12 1 25 1 power supply to the M2DU Connect a USB 2 0 cable between the M2DU and the 2 Batteries PC The Found New Hardware USB Computer Device wizard will appear Do not let it DataRay Inc USB2 0 devices search on the web Select No not this 2 DataRay gt USB2 0 M2 Stage vi VID 1632 PID 4001 time WHEN ASK it to Install tne sortware DataRay gt WinCamUCM USB2 0 v1 VID 1632 PID 2001 automatically Recommended It should find and install the driver highlighted in this Device Manager screen 6 Laser Safety The beam will suffer some back reflection from lens surfaces and ND filters and from the housings if the beam is misaligned You are totally responsible for your own laser and eye safety and that of others in the vicinity If you cannot accept this responsibility proceed no further 7 Preset the Attenuation level correctly Avoid destruction of your camera If you did not already do so earlier for the value of 2Wo calculated in the Beam Modeling for Lens Selection Excel sheet above from the curves in the WinCamD manual page 1 7 for CW 1 8 for pulsed determine whether you will need to add additional sampling attenuation in order to avoid saturation of the
14. ble lens options Contents Page 1 Description 2 2 Beam Modeling for Lens Selection 3 3 Parts List 4 Wavelength 632 nm Black X axis 4 Getting Started 5 Fears o Waist aaa 5 Assemble the unit 6 Current Z location 0 1 mm Div Asymmetry 1 037 6 Laser Safety 7 lt 4 Decrement Sample Manual mode Increment Sample gt gt 7 Preset the Attenuation level correctly 7 Show 3D view Use clip widths at O and 90 deg Use major minor widths 8 Start the Software 7 Setup M2 Save M2 Export Data 9 Align the Beam 9 suto M2 Set ome Recall M2 Close M2 Dialog 10 Set the Capture Block 9 11 Check Exposure 2 optionally subtract residual noise 9 12 Perform a Coarse Scan 11 13 Perform a Final Scan 11 14 Source Beam Characteristics 12 15 Save the data 12 16 Second time around 13 17 Support 13 18 Manual M with a different translation Stage 14 Known M2DU bugs in Version 6 00S2d Inclusion region on small complex beams may lose track Saved files sometimes open incorrectly Expected correction mid Feb 08 Future updates are downloadable from http www dataray com files iDataRayUpdate exe 1 Description The USB 2 0 M2DU accessory converts WinCamD beam profiling cameras into a compact fully ISO 11146 compliant M measurement system The M2DU system comprises a lens fixed to the front of a 42 5 mm travel stage on which the WinCamD is carried An achromat refocuses an input beam to a waist within
15. e o 3m 10 ft USB 2 0 cable A to mini B 5 o DRPSU 12 1 25 1 Power supply with US power cord o M2DU WC Mounting Block o M2DU WC LMB Lens mount bracket o LNZ XXX YYY Achromatic lens in holder plus spacers For some applications wavelengths a different LNZ XXX YYY will have been provided where XXX is the focal length in mm and YYY is the coating wavelength range This will come with one or more spacer tubes that set the lens at the correct distance o 8 pieces of 4 40 x 0 5 Philips panhead stainless steel black screws 2 spares Attach the M2DU WC Mounting Block to the rear of moving block on the M2DU stage using two 4 40 x 0 5 SCrews Attach the WinCamD U series head to the M2DU WC Mounting Block using two 4 40 x 0 5 screws Attach the M2DU WC LMB lens mount bracket to the front of the M2DU stage using two 4 40 x 0 5 screws Optional Attach the M2DU WC LMB lens mount bracket to an optical table breadboard or other hardware using two 4 20 x 0 5 screws you supply If your hardware is Metric use M6 x 12 5 mm caphead screws you supply To mount it higher attach either through these holes or to the threaded holes in the base of the unit IMPORTANT If you use the threaded base holes screw length inside the unit must never exceed 0 375 10 mm Add the LNZ XXX YYY lens assembly The standard lens provided is a 100 mm achromatic If you use a longer focal length lens use an appropriate additional spacer tube These
16. e waist diameter amp z location of the source beam Zo Delta LPPSO Lens You need to know the focal length mm and back focal length mm of your lens Enter in the table below Lens mount You need to determine the distance Zo Delta mm from the front of your lens mount to the rear principal plane of the lens Enter in the table below i Lens mount You need to determine the distance LPPSO mm from the lens rear principal plane to the sensor plane when at O on your measurement scale Enter below Lens focal length Lens back focal length LPPSO Enter in M2 dialog Zo Delta Enter in M2 dialog Lens Principal Plane to Sensor at O Front of lens mount to Principal Plane d Move the camera in z and determine that the waist is around 50 to 75 along an attainable range of travel e At Step 8 above when the M Squared Setup dialog screen Squared Setup x opens enter the listed parameters plus the wavelength in nm Number of Samples Translation stage maximum travel 632 8 i LPPSO see User Guide 72 mm c 10 Lens Focal Length in mm f 15 I 00 0 rm jf 20 20 Delta from table in User Guide m 6 70 rrr Translation stage maximum travel if manual 100 f 60 29 40 Averages per Sample oe Pe tS e ULB Ce 6 Stage Setup Cancel f g h When you start the software with no M2DU stage connected the M Squared Dialog will say Manual mode below the graphic area of the dial
17. e zero or background noise will skew the Variance reading to larger values b In accordance with Section 5 1 of the ISO 11146 Standard the Second Moment calculation integrates over 99 of the total energy in the profile See Appendix B for Beam Diameter definitions c If the beamwaist profile in the propagation direction the z direction is either too flat or too V shaped the fit will be poor d With the lens provided the system will measure the M of collimated lasers If you already have an appropriate beamwaist and can position it within the range of travel of the stage you can measure the M of the beam directly 5 Assemble the unit The diagram shows the unit with an 85 mm lens For longer focal length lenses the lens assembly moves to the left in the diagram below The measurement LD mm is required for the calculation of the original beam characteristics WinCamD U series camera Aoo ii a fj iT waer A BNE TTL Tigger VO sensor USB 2 0 Screw on Aey a M2DU WC Mounting Block various Sizes n 3 075 E 78 1 mm h2 V input If ordered as a camera M2DU system you should receive the unit completely or partially preassembled If not assemble as follows You will should have been supplied with the following parts WinCamD U series head M2DU WC XXXXXX system comprising the following items o ND2 0 additional ND filter to screw onto the ND4 0 provided with the camera o M2DU UMove USB 2 0 stag
18. es no sense and rechecking the procedure did not help then 1 Scan through the saved images to see whether or not you have a dirt dust exposure time or Capture block issue affecting the image 2 If 1 showed nothing that explained the problem then save a m2_wef file or at least an wecf image saved from the data set Email the file with comments to support dataray com Then as necessary call 303 543 8235 7 30 to 18 00 Mountain time zone GMT 7 hours Note that m2_wef files can be large ten s of MB We can receive large files but your email server may restrict attachment size In that case either put them to an FTP location on your server and tell us how to download them or try using http www sendthisfile com 18 Manual M with a different translation Stage If you have a WinCamD camera but no M2DU unit the procedure is identical particularly with respect to alignment exposure laser safety capture block etc Before trying to perform a Manual M you must first read and understand the full document carefully except for items relating specifically to the parts list and assembly of with the M2DU unit Exceptions to the procedure are as follows a Stage Travel Determine the length of travel of your alternative z stage be it motorized or manual b Stage Readout The stage must have a readout in mm be it digital or manual c Source diameter amp location To additionally determine th
19. hlights in yellow the required lens diameter plus the length of spacers required to place the beamwaist within the range of the stage The lines on the auto scaled graph show Beamwaist profile AFTER lens for your beam Beam must NOT be flatter than below this line e The estimated post lens beamwaist profile an Lower beamwaist limit due to profiler resolution e The calculated flattest acceptable beamwaist maximum Rayleigh Range for this stage 300 The minimum allowed beam waist for the chosen profiler 250 If the beam waist is too small for the camera or the curve is too flat warnings with advice will appear next to the values You may need to be in the far field of the laser in order to form a beamwaist within the range of travel of the stage N a O 150 S Avoid destruction of your camera sensor For the calculated value of 2Wo boxed in green above from the curves in the WinCamD manual page 1 7 for CW 1 8 for pulsed determine 100 whether you will need to add additional sampling attenuation in order to avoid saturation of the camera at the focus If so add as required before 50 proceeding Beam Diameter in um An additional ND2 0 filter is provided as standard Chapter 5 of the WinCamD manual describes 0 attenuation and sampling solutions DataRay offers 0 10 20 30 40 50 additional ND filters variable ND filters wedge samplers amp holographic beam samplers to assist you
20. ion before working with the M2DU stage IMPORTANT You will require Windows XP with SP2 or Windows Vista with gt 1 GB of RAM for WinCamD UXXxX with the M2DU If you only have 512 MB of RAM then with this multiple image based measurement system you will probably find that your computer slows significantly even freezes and there is nothing that we can do to help you A minimum screen size of 1024 x 768 pixels is required Recommended is 1280 x 1024 or higher Windows Support We no longer support Windows 2000 If you see problems in Windows 2000 which we do not see in XP then we will not put effort into curing them we will simply recommend that you move to XP or Vista If you do not have an M2DU stage and wish to perform an M measurement using a different stage manual or automatic request a separate User Manual entitled WinCamD Manual Z Entry M Applicable Standard ISO 11146 Test methods for laser beam parameters Beam widths divergence angle and beam propagation factor Available from http webstore ansi org ansidocstore default asp requires Use of the Second Moment 40 or Variance definition of the beam diameter Averaging of 5 samples at each position in z A minimum of ten samples in z half of them shall be distributed within one Rayleigh length on either side of the beam waist and half of them should be distributed beyond two Rayleigh lengths from the beam waist DataRay offers from 10 to 60 samples in z
21. og Set the camera to your start position which need not be zero on the scale Press Go and let the image and exposure stabilize Press Start M2 Obviously Auto M2 Setup is grayed out if you do not have an M2 stage The following dialog will appear Enter Parameter Dialog x Enter curent position in mm Cancel The position highlighted in blue is the software s best guess at what the position will be based upon the entered stage range and the number of steps You may use these values or you may ignore them your call Enter the actual z position no need to include mm rather than blue value Press OK The screen right will appear You may use the recommended position or one of your choosing Once the position is set press OK and after the image exposure has stabilized the next reading will be taken The screen above will reappear with a different position option M Squared Dialog Output Beam Results NA u 0 000 NA v 0 000 View Source Set full range lt 4 Decrement Sample Manual mode Show 3D view Use clip widths xy Use 1SO_majoreminor Setup Mz Start M2 Re Calc Recall M2 Close M2 Dialog 3 DATARA 1 Reccomended next position 11 00 mm Position then press OK when ready If you take too long between readings the dialog shown right a will appear Simply select No to cancel it Follow through the sequence until the requested number of
22. order to ensure that it can be correctly measured with the received system Input data fields Bin io i 72 p Lens Choice for M Measurement 2006 2008 DataRay Inc Click for IS0 11146 criteria Clicking on the Excel cell offers both input advice and the Select Profiler WinCamD UCD12 45 5 um Min beamwaist selection of options where stage Model MZDU 44 mm Stage range appropriate Beam Quality Factor M 1 05 Wavelength 4 675 nm Input beamwaist diam 2Wa 2 mm Select Lens Focal length F 150 mm Input beamwailst to lens dist 3 300 mm Optimize 1 Increase s then vary F if necessary Optimize 2 Decrease s then wary F if necessary Output data fields Lens mount to desired zero plane Max Rayleigh range for stage Input Far Field Divergence 6 Input Rayleigh Range ZR Beam Diameter at lens Min clear lens aperture Magnification f of beam after lens Output beamwaist 2VVo Output Rayleigh Range zR Output waist to lens dist s Output waist position in scan Focal plane to beamwaist _ Estimated 3 zR Scan Start position Estimated 0 5 2R Min Scan Stop position Tei Add t ee 60 Sample interval in um Enter the values for your beam in the light blue shaded cells The results of the Gaussian optics calculations appear in the dark pink shaded cells and a curve appears below The output data fields show several factors and hig
23. racket to sensor Set full range Lens mount bracket Let s double check You did all your calculations in mm and to 1 mm or better correct Zo Delta Enter the value for your lens from the table above Translation Stage maximum travel is automatically read from the stage EEPROM when a stage is present lt lt Decrement Sample Manual mode Increment Sample gt gt Show 3D view Use clip widths at 0 and 90 deg Use major minor widths Click OK and the M Squared Dialog shown right will appear ae SetupM2 Stm2 Eense To stop it from blocking the screen resize the main screen away from its default full screen setting E x 9 Align the Beam Correct alignment is critical to successful operation A misaligned beam can lead to astigmatism and to overestimation of the M value You are aiming for on axis to 2 mm max The M2DU stage sets the optical axis at a height of 3 08 78 2 mm above the base ae all The lens and camera covers have black on white beam target crosshairs with 5 and 10 mm circles These are useful for visible lasers The lens cameras have a central hole For NIR and telecom lenses the lens cap includes a pink fluorescent phosphor on the cap For the camera end you may require suitable wavelength imaging plates or viewers With these covers in place a Click on the right hand edge of the gray scale to move the stage to the end closest to the motor b Align the beam on the target on the
24. rlier This is a distance that is easy for you to measure It must then be corrected for the distance Averages per Sample between the front of the lens and its Principal Plane and for Cy ro the distance between the rear of the lens bracket and the sensor in the camera Cancel Add this value to the value shown in the table below for the __ Cancel lens see label on lens and enter this value in the LPPSO Lens Principal Plane to Sensor at 0 entry in the dialog Enter the Zo Delta value for the lens in the dialog Copy LPPSO amp Zo Delta to the front page for your convenience Lens LD User measured A Zo Delta LPPSO Enter in M2 dialog Zo Delta Enter in M2 dialog LNZ f mm Diam See diagram below See diagram below Lens Principal Plane to Sensor at O Front of lens mount to Principal Plane 9 7 User s own lens LNZ 75 UV LNZ 75 VIS LNZ 75 NIR LNZ 75 TEL LNZ 85 VIS 33 1 Fixed 274 Legacy lens LNZ 100 UV LNZ 100 VIS LNZ 100 NIR LNZ 100 TEL LNZ 150 UV LNZ 150 VIS LNZ 150 NIR LNZ 150 TEL LNZ 150 50 UV LNZ 150 50 VIS LNZ 150 50 NIR LNZ 150 50 TEL LNZ 250 UV LNZ 250 VIS LNZ 250 NIR LNZ 250 TEL LNZ 250 50 UV LNZ 250 50 VIS LNZ 250 50 NIR LNZ 250 50 TEL LNZ 500 50 UV LNZ 500 50 VIS LNZ 500 50 NIR LNZ 500 50 TEL 5 LD mm User measured Zo Delta mm Lens rear principal plane to front of mount M Squared Dialog 0 0 mr Theta _v 0 000 NA v A mm Rear of lens mount b
25. samples have been entered at which stage the results will appear instead of a dialog box Stop M2 Increment Sample gt gt As you read about using the M2DU stage you will probably have to iterate the positioning and the number of samples until the curve looks right and there are no Warnings
26. sion of the scan the software performs a hyperbolic weighted least squares fit to the data to calculate the approximate position of the beamwaist zO and the Rayleigh Range ZR Based on these values the software produces estimates of the full results More importantly the ASR Auto Scan Range software module sets upward pointing white tick marks on the scale at the suggested Start and End positions for a 11146 compliant scan If the scan is too flat for an accurate M fit because the far field is not adequately reached within the range of the scan in accordance with the Standard then Warning Beam waist too shallow will appear If the exposure dips below 0 25 ms Warning More attenuation recommended will appear in the Exposure area due to the risk of tailing with CCD s If the exposure rises above 200 ms Warning Less attenuation recommended will appear in the due to the risk of dark noise contribution to the ISO diameter 13 Perform a Final Scan Unless you have reason to disagree with the proposed scan range press Start M2 The software automatically performs a scan of 60 equally spaced points in z over the set range with an Average of 5 images per z position At the conclusion of the scan the software performs a weighted least squares hyperbolic fit to the data to calculate the final results M 2_u v the M values Remember the anticipated specifications M Accuracy 5 typical M Repeatability 2 typical
27. the stage travel range The standard is 100 mm focal length Alternative lens focal lengths and coatings will be recommended supplied for some lasers A spreadsheet simplifies the choice ASR auto sampling measures the hyperbolic region about the waist and at ZR gt 2 in accordance with the ISO standard A least squares hyperbolic fit to the second moment diameter data allows calculation of the M value and related parameters for both the focused beam and the source beam M Beam Quality Factor Explained M or Beam Quality Factor is a dimensionless parameter that characterizes the degree of imperfection of a real world laser beam The closer the M value is to 1 0 i e the closer the beam is to TEMoo Gaussian perfection the closer the beam can be focused to its diffraction limited spot size Due to limitations of the optical cavity the lasing medium and or the output ancillary optics most beams are not the perfect diffraction limited Gaussian profile pure TEMo9 mode described in textbooks Complex beams can contain multiple TEM contributions leading to high values of M At its simplest M may defined as The ratio of the divergence of the actual beam to that of a theoretical diffraction limited TEMoo beam with the same waist diameter The measured far field full angle divergence of the actual beam Q 0 The theoretical far field divergence of a perfect TEMp Gaussian beam which has the same waist
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