Crossover frequency of PZT and temperature loop is ~0.1Hz (See top left panel of figure 1).
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Actuator efficiency ratio A_temp/A_pzt is ~10dB [V/ct] in DC (See top center panel of figure 1).
=> According to the spec. sheet of Mephisto laser, actuator efficiency is 1MHz/V (PZT) and 2GHz/V (Temp.)
A_temp/A_pzt = 2 [GHz/V] * 1 [MHz/V] * 305 [uV_diff/ct] * 0.5 [V_se/V_diff] ~ -10dB [Hz/ct]
Above 1Hz, phase delay dosn't match between measurements and model (See figure 2).
=> Maybe we need to consider dead-time model.
But it can be ignore because the contribution of temp. loop to OLTF is small above 1Hz.
