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 * Can we add a heater back to OMC mirror to control ROC? How should the temperature be sensed and controlled?

Balanced Homodyne Detection

Requirements

  1. Displacement noise of OMC/LMC mirrors
  2. Scatter loss in mirrors
  3. Cavity design: triangle, quad ring, quad zig-zag (reference the new OMC paper from Koji)
  4. Laser amplitude / frequency noise including DC offsets in various other lock points and motions to simulate bilinear noise
  5. Oscillator noise: AM / FM
  6. Aux length noise: MICH/PRC/ SRC
  7. Req. on offsets/asymmetries: arm finesse, arm reflectivity, mass imbalance of ETMs
  8. Phase noise of LO
  9. Polarization stability requirement for polarization BHD
  10. Backscatter

Action items

  • Design SRC so that
    1. Suppress 02/20 modes
    2. Partially transmit 01/10 modes for AS WFS
    3. Suppress thermally generated modes
    4. After the above have been satisfied, choose transmission to maximize ponderomotive squeezing
  • Budget above noises, but especially investigate polarization stability.
  • How is homodyne angle controlled?
  • Beam routing
    • Where to pick off LO?
    • Can we use ETMX transmission for LO? (Koji is crazy)
  • A+ BHD noise budget for both baseline double OMC and polarization BHD.
  • Can we add a heater back to OMC mirror to control ROC? How should the temperature be sensed and controlled?

Modeling/Noise Budget

  • Some BHD modeling is done in the OptimalGWextraction repo here.

Polarization BHD

Balanced Homodyne Detection (last edited 2020-04-29 17:41:39 by JonathanrichardsonATligoDOTorg)