I recalculated the mode matching so that the spot radius in AOMs is 100 um. Now the visibility of RCAV is 90%.
From the previous mode matching calculation, the spot radius in AOM is 220 um. This was too large for ISOMET AOM and caused beam distortion. The AOM was designed for much smaller spot radius (50 - 110 um). So I recalculated to make the spot radius inside the AOM to be 100 um. This spotsize is small enough for ISOMET and not too small for Crystal Tech AOM.
Rise time is 35 ns (28.5MHz) for 100 um radius in ISOMET AOM, diffraction eff ~80%. This should be sufficient for our less than 1MHz bandwidth loop.
For the new layout, I have to remove the Faraday isolator behind the EOM for another lens. I'll try to intall it back later.
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