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AkihiroTomura - 16:11, Wednesday 01 November 2017 (579)
SHG transfer function
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.
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.
Images attached to this report
Comments related to this report
I'm not convinced on what we see in the mechanical TF of the SHG: at low frequency the behaviour of that TF should be flat, while in our case is not. It seems that there is a low pass included somewhere around 50Hz. If so, this lowpass might be the cause of the low phase margin at the unitary gain frequency (1kHz).