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Entry  Thu Apr 16 18:03:22 2020, aaron, Update, PSOMA, preliminary PSOMA layout PSOMA_layout.pdf
    Reply  Tue May 12 10:15:30 2020, aaron, Update, PSOMA, preliminary PSOMA layout whiteboard_configs.zipring_MZ_config.pdf
Message ID: 2496     Entry time: Tue May 12 10:15:30 2020     In reply to: 2494
Author: aaron 
Type: Update 
Category: PSOMA 
Subject: preliminary PSOMA layout 

I've updated the PSOMA optical layout. I still have some questions on locking, and there are a few additional configurations that we could try. In particular:

  1. Amplifier cavity as a 2-port device (signal and pump mixed before reaching an overcoupled amplifier cavity)
  2. Amplifier cavity as a 4-port device (signal and pump enter the cavity through different ports)
    1. Overcoupled case -- 'signal out' at the same mirror as 'signal in'
    2. Critically coupled case -- 'signal out' through the 'pump in' port

Each of these configurations also has a couple different ways to pickoff an LO for homodyne readout. Shruti and I enumerated these configurations on a zoom whiteboard a couple weeks ago, and I've attached them (the zip contains png).

Chris also mentioned last week that we may run into a frequency-dependent loss in the critically coupled cavity configurations. The pdf I've attached shows a configuration that I think is a minimal modification of the Mach-Zehnder amplifier described in PSOMA. One of the ring cavities is replaced with a tunable steering mirror, and the LO is picked off before the pump reaches the MZ.

In the new diagram, I'm thinking about controlling the following degrees of freedom:

  • Signal phase relative to pump phase
  • Pump frequency relative to amplifier cavity resonance
  • pump intensity
  • MZ relative path length
  • Homodyne mixing angle
  • Signal and pump spatial mode

Some things I'm unsure about:

  • I am not currently controlling signal laser intensity -- can this be done by sending the first order AOM beam to a PD rather than dumping it as shown?
  • Not sure about the right place to place several of the EOM
  • If we have transmission through the cavity's curved mirror, is the associated loss acceptable?

Shruti and I are now tracking our work on git issues in the PSOMA repo.

Attachment 1: whiteboard_configs.zip  626 kB  Uploaded Tue May 12 11:36:40 2020
Attachment 2: ring_MZ_config.pdf  107 kB  Uploaded Tue May 12 11:36:55 2020  | Hide | Hide all
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