We increased the output laser power from PSL. And also I adjusted the input power to FSS path to same as estimated power after PMC installation. That power is smaller than priviouse power by factor of 10. So to gain larger error signal, I put RF amplifier (ZHL-1A-S+, 20dBm) between RFPD and demodulator and increased the modulation signal amplitude.

For that some configurations were changed. The below list are the current setup.

Laser Power
20mW@output of PSL
4mW@pick off mirror for FSS

Modulation signal amplitude
FSS;16dBm(19dBm at function generator and splitted to modulator and LO.)
IMC: 0dBm(-9dBm at function generator.)

Gains

TTFSS common gain: 14dB
TTFSS fast gain: 15.4dB
IMC IN1GAIN: -32dB
IMC MCL-SERVO gain: -0.2

signs

TTFSS fast pol: -
IMC IN1POL:+
IMC SLOWPOL:-