Yuhang and Michael

We attempted to obtain a proper ringdown signal of the cavity by switching off the 1st order diffraction passing through the AOM. We used the following methods:

1) Turn off the RF signal from Anritsu function generator to AOM

2) Amplitude modulate the RF signal from Anritsu by using Mokulab - a square wave of frequency 1 Hz was input to the Anritsu external modulation port such that the Anritsu signal would oscillate between normal and zero, with an "instant" change (quotation marks).

3) Frequency modulate Anritsu signal, which would then make the AOM efficiency effectively zero. But the Anritsu only allows 1 MHz/V modulation, so it wasn't enough.

These methods produced ring down signals that were nowhere as fast as what was expected - we measured microseconds but are expecting nanoseconds ringdown. So even though the AOM can be turned off more quickly than what we could get by mechanically blocking the beam, we are still limited by the deactivation speed of electronic switches.