- #1
Doc
- 47
- 4
Hi all,
I am a mechanical engineer so I'm hoping to get a bit of guidance on something I am working on at the moment. I am working on a project which requires we keep actively keep a laser beam centered on a mirror. The mirror transfers a small percentage of beam power and I am hoping to use a quadrant photodiode to detect the position of the beam. The beam has a gaussian distribution, and the beam size will be larger than the active area of the photodiode due to physical constraints. The way I understand that this will function is that the incident beam flux on the photodiode will result in the photodiode generating output current. My question is:
How can I detect where the bright central core of the beam is (I don't care about the low power outer regions of the beam.)?
My feeling is that I will be doing this anyway: whichever quadrant the highest amount of flux is incident upon (if the bright core is mostly in one quadrant), then that quadrant will be outputting the most current, see Figure 1 below.
If I then needed to drive another mirror earlier in the system to recenter the beam, I assume that I effectively would want to move the active mirror in such a way that results in i1=i2=i3=i4 (approximately).
Am I understanding this correctly?
Thanks,
Doc
I am a mechanical engineer so I'm hoping to get a bit of guidance on something I am working on at the moment. I am working on a project which requires we keep actively keep a laser beam centered on a mirror. The mirror transfers a small percentage of beam power and I am hoping to use a quadrant photodiode to detect the position of the beam. The beam has a gaussian distribution, and the beam size will be larger than the active area of the photodiode due to physical constraints. The way I understand that this will function is that the incident beam flux on the photodiode will result in the photodiode generating output current. My question is:
How can I detect where the bright central core of the beam is (I don't care about the low power outer regions of the beam.)?
My feeling is that I will be doing this anyway: whichever quadrant the highest amount of flux is incident upon (if the bright core is mostly in one quadrant), then that quadrant will be outputting the most current, see Figure 1 below.
If I then needed to drive another mirror earlier in the system to recenter the beam, I assume that I effectively would want to move the active mirror in such a way that results in i1=i2=i3=i4 (approximately).
Am I understanding this correctly?
Thanks,
Doc