Beam Profiler FAQ’s

Slit-Based Profilers

08/30/15

The detector is mounted internal to the NanoScan behind the rotating slits. This position is not important to the measurements. The measurement plane is the scan plane of the slits, which is nominally 0.74mm +/-0.025 mm from the Reference Surface on the front of the NanoScan. Please refer to the mechanical drawings in Appendix B of the NanoScan Operational Manual.

03/05/19

The precision and accuracy of the 3.5mm and 9mm aperture systems is the same. It is the slit width that affects accuracy; with 3% for beam diameter (dslit) and <1um 3-sigma centroid accuracy. The slit width affects beam diameter due to convolution error. However, this error is on the order of <5% when the slit is only 4x the beam diameter. Thus, this only comes into play when the beam is ~20um for the 5um slit, 100um for the 25um slit, and 7.2um for the 1.8um slit. It is also possible to correct for convolution error. This is discussed in the manual for Gaussian beams. Generally it is not an issue with most users.

03/05/19

This depends on the size of the beam, relative to either the slit width for "small" beams, or on the aperture diameter for "large" beams. Standard NanoScan apertures are either 3.5mm or 9mm, with 1.8µm, 5µm, 10µm, or 25µm slits. Standard Large Aperture (LA) NanoScan apertures are 12.5mm or 25mm, with 10µm or 25µm slits. (Please note that LA models are no longer available.)
 
The scanning slit introduces a systematic convolution error in measured spatial beam diameters that depends on the slit width "w" and the beam diameter "d". This error increases as the ratio of the slit width to the beam width increases. However, since the error is systematic it can be corrected, and this is discussed in detail in the NanoScan Manual Section 4.4.9 for TEM00 Gaussian beams.
 
The NanoScan accuracy specification for measurement of dslit diameter is 3% for all models of scan heads. As a rule-of-thumb, the convolution error only becomes significant for small beams when the 1/e2 beam diameter is of the order of 4 times the slit width, or d≤4w. For a Gaussian beam with d=4w the error is only approximately 3.7%.
 
The aperture diameter determines the largest beam that can be measured, and this depends on the shape of the beam, say Gaussian or Flat Top. A Flat Top beam can be almost the aperture size. To measure d4 it is necessary to acquire the full profile including the tail out to where the amplitude is <1digital count. For a Gaussian beam with 12-bit digitization, the beam is then limited to ~1/2.1 or ~0.476 × the aperture dimension. To be on the safe side a good rule-of-thumb here is to use a factor of 0.4, so the aperture is 2.5 × the 1/e2 beam diameter. However, if one wants to just measure a clip-level dslit diameter, it is only necessary to acquire the profile out to slightly less than the clip-level diameter. As examples, it is possible to measure a Gaussian beam with 8.9mm 1/e2 diameter using a 9mm aperture scan head. It is also possible to measure the FWHM diameter of a Gaussian beam with 15mm 1/e2 diameter.

03/05/19

Error Code -22 is indicating Nominal baseline could not be determined. There are several causes for this, including detector failure, detector overheating with a high power laser, failure of the amplifier gain setting interface, and too much laser illumination incident in the aperture at program launch. If this error occurs, make sure the laser is blocked from entering the scan head aperture and try restarting the software. If the system was used for high power laser profiling, let the scan head cool down before restarting the software. If these attempts fail the unit likely needs to be returned.

09/07/15

There are two different models of the LD8900 Goniometric Radiometer (far-field profiler), the LD8900 and LD8900R. The former is an 8-bit system and the latter a 16-bit and they have different controller cards and software. If you have both systems in your facility be sure that you are loading the correct software type for the instrument you are trying to operate. Mixing either the software or the controller PCBs for these will result in this non-performance symptom. Make sure that you get the correct software for your system—16-bit LD8900R for the LD8900R or 8-bit LD8900 for the LD8900.

03/05/19

The power meter available as a standard option on silicon and germanium detector NanoScan systems is a "relative" measurement, which means that the meter is not calibrated to an absolute standard in the factory. You need to measure the source with a calibrated power meter, and then input the value into the NanoScan software. The NanoScan will then measure relative to this measured value.

03/05/19

This indicates that the NanoScan is a legacy NanoScan sensor which is programed only for the version 1 software, which is listed under legacy software as v1.47. If you do want to use the version 2 software, it is possible and it requires the purchase of the software license key as is described in the Notes on the software download web page below the Photon NanoScan v2 download links.

03/05/19

The NanoScan is a PC application and intended to operate on the Windows operating systems. However, it might be possible to use the NanoScan with a Mac, provided that the Mac has installed the Parallels and Windows operating system available from your Apple dealer. The NanoScan might operate under the virtual Windows machine, but this operation and functionality is not supported.

03/05/19

The NanoScan software version 1.47 for the USB interface works with Windows 7 64-Bit. NanoScan software version 2.X for the USB interface works with Windows 7 and Windows 10 64-bit.

03/05/19

The NanoScan V2 product is great for looking at focused spots, but sometimes the C-Mount ring that is on the front can get in the way mechanically. By removing the three retaining screws it will allow you to remove this ring so you can get mechanically closer to the front of the NanoScan V2. Care should be used when removing these screws and the ring so something does not fall down inside the input aperture of the NanoScan V2. It is recommended that if you are going to remove the C-Mount ring that you invert the NanoScan V2 so it is looking at the floor and then remove the screws and the C-Mount ring to allow gravity to work in your favor and pull them away from the input aperture.

03/05/19

Some users have reported an error message when attempting to install the latest versions of the NanoScan software:
 
Error 1330.A file that is required cannot be installed because the cabinet file C:\Users\Administrator\AppData\...\Data1.cab has an invalid digital signature. This may indicate that the cabinet file is corrupt.
 
This error is not caused by a corrupted file or anything in the NanoScan software. Windows systems that have not been updated recently, may fail to validate the digital certificates that are now used with our installers; specifically the missing updates are any that say Œroot certificates update¹ or similar. This is a common occurrence in laboratory environments as the PCs are often isolated from the internet and/or not updated often. Updating the computer to obtain the current VeriSign certificates will resolve the problem.

03/31/19

ROI is “Region Of Interest”, there are 2 main reasons to use it, the first is if you like to select smaller region from the entire frame and by that to remove noise areas that can harm the measurement results. The second one is to give the ability of multiple beam analysis – up to 16 beams where separate results will be computed for each enabled ROI

03/05/19

There are far fewer configurations of NanoScan head than there were BeamScan models, because some of the features that were hardwired into BeamScan models are software adjustable in the NanoScan. For example, some BeamScan models were wired to run at 5Hz, instead of 10Hz, and this feature was part of the model number. This is unnecessary in the NanoScan, because the scan rate is controllable from the application software. Another model that is no longer necessary is the LL, or low light version, since the increased dynamic range of the NanoScan handles low intensities without modification. Below is a chart of the best fits for replacing a BeamScan. One thing to note; all standard NanoScan models are 63.5mm diameter scan heads, so there is no direct replacement of the XYLA (50mm) models of BeamScan.

 

BeamScan Model NanoScan Model
XY NS2s-Si/3.5/1.8
XYGE NS2s-Ge/3.5/1.8
XYS NS2s-Si/9/5
XYGET NS2s-Ge/9/5
XYFIR NS2s-Pyro/9/5
XYQSW NS2s-Pyro/9/5
/PWR200 /P200
Other BeamScan designations All NanoScan 2s systems are USB
0180-XYxxx Old ISA Controller card
3088-1-XYxxx PCI Controller
3088-3-XYxxx PCMCIA Controller for laptop
2180-XYxxx DOS-Based computer controller
2197-XYxxx DOS-Based computer controller (replaced 2180)
BeamScan Meters No direct NanoScan replacement
1180-CP Standalone (non computer based) with single axis Si scan head (50mm diameter with 1.8um slits)
1180-GP Standalone controller with single axis Si scan head (63mm diameter with 5 and 25um slits)
1280-XY Standalone controller with dual axis Si scan head (50mm with 1.8um slits)
1280-XYL Standalone controller with dual axis Si scan head (63mm with 5um slits)
1280-XYFIR Standalone controller with dual axis pyroelectric scan head with 5um slits