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Entry  Mon Jul 29 14:46:09 2019, Nathan Holland, DailyProgress, 2micronLasers, Optical Phase noise of 2 um Mach Zehnder Interferometer. Optical_Phase_Noise_Spectra_2um_Mach_Zehnder__20190729.pdf20190729__Initial_Phase_Noise_Measurement_setup.pdfMeasured_phase_spectra_2um_Mach_Zehnder__20190729.pdf2um_Mach_Zehnder_data__20190729.hdf5
    Reply  Mon Jul 29 15:46:50 2019, Koji, Laser, 2micronLasers, Optical Phase noise of 2 um Mach Zehnder Interferometer. 
Message ID: 2377     Entry time: Mon Jul 29 14:46:09 2019     Reply to this: 2378
Author: Nathan Holland 
Type: DailyProgress 
Category: 2micronLasers 
Subject: Optical Phase noise of 2 um Mach Zehnder Interferometer. 

Figure 1, attached, shows the phase noise I measure from the 2 um Mach Zehnder interferometer. This phase noise is from the optical path and is affected by:

  • Intensity noise.
  • Laser frequency noise.
  • Differential polarisation shifts through the IFO arms.
  • Changes in differential arm length.
  • Changes in refractive index.
  • Detector noise, in which I am also grouping noise due to the amplifier.

The next step is to determine contributions from each of these sources.

Attachment 2 shows the setup used to measure this noise. Attachment 3 shows the measured phase spectra from both phasemeters of the Moku. Attachment 4 contains the both time series and spectra. The spectra shown here are:

  1. Converted to radians, from cycles.
  2. Subtracted, in time domain.
  3. Converted into power spectra, using Welch's method, 30 averages and Hanning windows.
  4. Converted into amplitude spectra, by taking the square root.
Attachment 1: Optical_Phase_Noise_Spectra_2um_Mach_Zehnder__20190729.pdf  59 kB  Uploaded Mon Jul 29 15:50:03 2019  | Hide | Hide all
Attachment 2: 20190729__Initial_Phase_Noise_Measurement_setup.pdf  69 kB  Uploaded Mon Jul 29 15:50:17 2019  | Hide | Hide all
Attachment 3: Measured_phase_spectra_2um_Mach_Zehnder__20190729.pdf  101 kB  Uploaded Mon Jul 29 15:51:34 2019  | Hide | Hide all
Attachment 4: 2um_Mach_Zehnder_data__20190729.hdf5  36.279 MB  Uploaded Mon Jul 29 16:05:05 2019
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