On 10/31, Matteo L, Yuhang, and Tomura did measurements of SHG transfer function.
We used Agilent 35670A network analyzer.
All traces are pieced together from traces with different frequencies span.
Firstly, we investigated frequency response of an adder we used (1st figure).
We got a flat response in magnitude and phase.
Secondly, we took dark noise spectra of the adder and Agilent 35670A (2nd figure).
Thirdly, we measured a mechanical transfer function of SHG (3rd figure).
We guessed a peak around 25kHz indicated a resonance point of PZT.
Lastly, we measured an open loop transfer function of SHG (4th figure).
Unity gain frequency is around 1kHz.