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Message ID: 2669     Entry time: Fri Feb 26 13:24:31 2021
Author: rana 
Type: Noise Hunting 
Category: Laser 
Subject: setup beatnote to Teraxion laser 

Aaron and I set up the beatnote measurement between the Teraxion and (either south or north) RIO:

  • mounted all the Teraxion stuff on the NW corner of the Green Monster table.
  • Used a high power (300 mW!!) fiber coupler to take ~1% of the beam and send that to the PSOMA table on the overhead PM fiber.
  • Aaron measured ~0.2 mW at the PD ?
  • The beat note amplitude is ~-15 dBm out of the New Focus 1611 (1000 V/A AC transimpedance)
  • Split the output with a RF splitter (NOT a BnC tee) to the 3 GHz spetrum analyzer and rack mounted Moku.
  • Recorded some phase meter data with the beat at ~148 MHz.

Turned Teraxion laser OFF around 9 PM. Analysis in progress if I can figure out how to get the data.

Next we'll have to do some careful temperature tuning to get the RIO laser into a low noise state and simultaneously have a beatnote < 200 MHz.

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