daniel.sigg@LIGO.ORG - posted 14:00, Thursday 20 June 2019 - last comment - 09:19, Wednesday 26 June 2019(50099)
Frequency noise from the laser
Here are some MC_F spectra.
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Modal analysis of the reference cavity can be found at the 40m wiki.
Here is the same spectrum with updated calibration. I neglected the 2 poles around 15kHz (Change 3 in E1900103).
The calibration for MC_F is:
- Gain: 10V/2^15 (ADC) * 2 (double pass) * 260kHz/V (VCO at DC)
- Poles: 1.6Hz (VCO), 10Hz, 10Hz (CM board whitening)
- Zeroes: 40Hz (VCO), 100Hz, 100 Hz (whitening), 2 complex 7kHz ± i*7kHz (Q=0.7), 10kHz (AA filter), 15kHz, 15kHz (CM board low pass)
In transmission of the IMC the cavity pole at 8.8kHz needs to be added.
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