I have isolated the DMD and I am currently shining three wavelengths of light at it (red, green and blue). The RGB is aligned in the same light path, but the RGB are all reflected at different angles. Is there a way to change it such that all RGBs are reflected with the same angle?
Thanks,
Aaron
Hey Philippe,
The lasers are aligned via a laser combiner.
After hitting DMD the light scatters quite a bit... > 
Note the scattering... and also that the green is centered, but the blue and red is in a diamond shape around it.
Thanks,
Aaron
Aaron,
Apologies for late response.
You may be encountering the effects of the wavelengths of your lasers in this case. The wavelength of the incoming laser light can impact the reflection angle as per the diffraction grating equation:
You should note that D is the pitch of of the DMD mirrors, and m is the diffraction order.
I hope this helps.
Regards,
Philippe Dollo
Hey Phillipe,
Thanks following up, I totally forgot about this.
Here is the design with the angle:
I did some more research after your previous tip and realized that what I might be seeing is possibly a blaze diffraction. Which maybe optimized for 1st orders for red and blue, didnt do any calculations, just a hypothesis.
I believe that the 0 order will be strongest when the beam is perpendicular to the dmd, I will have to give that a try. Unless, do you have any other ideas?
Thanks,
Aaron
