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Entry  Tue Oct 27 15:57:27 2020, shruti, DailyProgress, Lab Work, psoma locking  
    Reply  Wed Oct 28 12:42:31 2020, shruti, DailyProgress, Lab Work, psoma locking  Setup2020Oct27.pdfpsoma_PLL.pdfpsoma_pll_freespace_intermediate.pdf
       Reply  Thu Nov 19 11:23:44 2020, shruti, Update, Lab Work, psoma locking  PLL_FS_sym.pdfMZ_PLL_FS_sym.pdfNewBeat.pdf
          Reply  Tue Nov 24 10:16:04 2020, shruti, Update, Lab Work, psoma locking  BeatSetup.pdfBeatOrNot.pdf
             Reply  Fri Nov 27 13:38:18 2020, Shruti, Update, Lab Work, psoma locking  Beat.mp4BeatZoomed.pdf
                Reply  Fri Nov 27 19:43:33 2020, Koji, Update, Lab Work, psoma locking  
Message ID: 2577     Entry time: Wed Oct 28 12:42:31 2020     In reply to: 2576     Reply to this: 2582
Author: shruti 
Type: DailyProgress 
Category: Lab Work 
Subject: psoma locking  

Phase-locking the two lasers:

Updates:

- Although when we talked about adjusting the MZ-phase, we decided that having the phase/path length control with fiber components might be better initially (Refer Attachment 2), for now I began doing everything in free-space.

- Attachment 1 shows the setup as it is now. Previously I'd placed polarizing beam splitters instead of 90/10 beam-splitters because I thought it would be easier to work with, but now changed my mind and decided to stick with what we planned.

Next steps:

(Once the beat is obtained on the spectrum analyzer)

1. Adjust set-point temperatures to adjust beat frequency to the right frequency.
Since ideally we want the two frequencies to be identical, it might be a good idea to add an AOM to one of the paths so that the first order beam is mixed with the other laser and this beat be compared to a stable reference for phase-locking.
But, initially we plan to skip the AOM.
2. Adjust the PID parameters if needed
3. Add electronic components

- Measure the laser frequency noise


29 Oct 20:

I've added Attachment 3 -- which is the current free space version and some PLL electronics. 

- It does not show the Mach-Zehnder part as that will be added only later

- This setup is asymmetric but in a future version we will change that

Attachment 1: Setup2020Oct27.pdf  2.266 MB  Uploaded Wed Oct 28 13:43:12 2020  | Hide | Hide all
Setup2020Oct27.pdf
Attachment 2: psoma_PLL.pdf  599 kB  Uploaded Wed Oct 28 13:44:20 2020  | Hide | Hide all
psoma_PLL.pdf
Attachment 3: psoma_pll_freespace_intermediate.pdf  610 kB  Uploaded Thu Oct 29 18:13:37 2020  | Hide | Hide all
psoma_pll_freespace_intermediate.pdf
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