How is the Bragg condition satisfied for AOMs in a double pass configuration?

[Niles]

Hi

I have a question on AOMs used in a double pass configuration. I understand the motivation for such a setup, but what I don't quite understand is the following: During the first pass, the frequency of the incoming beam is changed from ω to ω+Ω at an angle θ_B. Then we send the diffracted beam with frequency ω+Ω through the AOM once again at the same angle θ_B. This last part I don't quite undertand: How can the Bragg condition be satisfied for the angle θ_B at both ω and ω+Ω?


Niles.

 

[The_Duck]

I think the idea is that in general Ω << ω, so the correct angle is essentially the same for the second pass as for the first.

 

[Niles]

Ah, I see. I thought it was most likely something like that, but I was worried that I had misunderstood something. Thanks for taking the time to reply.Niles.