Here's a plot of the AOM feedback signal. The SR560 is DC coupled with a gain of 10, and the calibration for the data is

6.1e-4 V/count / 10 x 700 kHz/V * lambda*S/4A * 2pi (rad/s)/Hz = 3.618e-4

6.1e-4 is the calibration from the DAQ, 10 is the gain from the SR560, 700kHz/V is the deviation set on the Techtronix function generator, S is the perimeter of the cavity, and A is the area. One side of the cavity is .7889m.