Diffraction Grating

[frankqt]

Hi All,

For a project of mine I like to get custom make diffraction grating optical element to be built.

I like this optical element to have 3 lines, with 6 degree half angle and 45 degree fan out angle. (i.e. angle between the center and side beams is 6 degrees) and 45 degrees along the line. I can spend a few K to get these parts custom built.

Are there any recommendations as per the companies who provide this type of service? I am building a laser scanner and I like to test this idea (Addition to David type thing)
Thx, Frank

 

[Bluefan]

If you have a scanner, why use a diffraction grating?

I don't completely understand what you want, but normal diffraction gratings can't make 3 distinct order (unlesss you just block off the rest, in this case not realistic). You're looking for 3 beams, separated by 6 degrees from eachother. A normal diffraction grating can't do that without many higher orders. You could try informing if it's possible to make a diffraction grating with 3 different periodicities superimposed.

Where does the 45 degree appear? Is this the beam divergence in the axis perpedicular to the line the 3 beams are on? This would make a beam looking something like this: |||
Adding a low periodicity in the other direction of the grating would make a lot of orders, appearing like it's continuous. But a high divergence in one axis is easier to do with a cylindical lens.

If the setup is stationary or doesn't move fast and the scanner can't make the movement, a system of beamsplitters, mirrors and lenses will probably do the same but much cheaper and probably more efficient.

 

[beam]

Hi,
For design DOEs you can use software, for example like LightTrans - Optical Engineering, Optics Software VirtualLab, Diffractive Optical Elements (DOE) Fabrication: Overview - here is available trial version.
May be it should by usefull for your purpose.
Regards,
B.

 

[frankqt]

Thanks for the answer. Apparently I don't really understand the diffraction optics. However what I am looking for is exactly what you describe however number of lines is not an issue for example, I can use 5 or 7 lines as long as the right most and left most lines are 6 degrees apart from the center one.

I will place this in front of a collimated laser beam (~5mW). The most critical item is that it must have exactly 6 degrees and there should be no lines following that.

I have been looking around for manufacturers and Holoeye is one and I am looking for others.

Thanks,
Frank

If you have a scanner, why use a diffraction grating?

I don't completely understand what you want, but normal diffraction gratings can't make 3 distinct order (unlesss you just block off the rest, in this case not realistic). You're looking for 3 beams, separated by 6 degrees from eachother. A normal diffraction grating can't do that without many higher orders. You could try informing if it's possible to make a diffraction grating with 3 different periodicities superimposed.

Where does the 45 degree appear? Is this the beam divergence in the axis perpedicular to the line the 3 beams are on? This would make a beam looking something like this: |||
Adding a low periodicity in the other direction of the grating would make a lot of orders, appearing like it's continuous. But a high divergence in one axis is easier to do with a cylindical lens.

If the setup is stationary or doesn't move fast and the scanner can't make the movement, a system of beamsplitters, mirrors and lenses will probably do the same but much cheaper and probably more efficient.