The current plot for PMC's OLG TF is plotted below. The RF V is 6V, Gain slider is 14 dB.
The UGF is 820 Hz with phase margin (PM) = 180 - 53 = 127 degree.
At higher gain slider setup, the system starts to oscillate. One possible cause is the peak near 10^4 Hz which
might be the PZT's resonance frequency.
Without the notch the total gain we can increase will be limited by the peak.
I'll make a notch to damp it down.
The current spec will be ~20dB notch at 12.5 kHz, FWHM ~1kHz
From current setup, the optical TF should be + 16.5 dB flat, and the gain added by the gain slider is +14 dB.
previous setup we have opt TF = -5 dB and +30 dB from gain slider.
So we have improved the overall gain by ~5 dB and to UGF increased from 530 to 830 Hz.