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Entry  Tue Apr 27 19:37:49 2021, shruti, Update, PSOMA, PDH error signal PDHerrorsig.mp4BeatNX20210427.pdfIMG_0215.jpgPDH.pdf
    Reply  Tue Apr 27 20:24:18 2021, rana, Update, PSOMA, PDH error signal 
    Reply  Fri May 7 13:15:07 2021, shruti, Update, PSOMA, Cavity locking, feedback to laser IMG_0217.pdf
       Reply  Mon May 10 10:20:54 2021, shruti, Update, PSOMA, Cavity locking, feedback to laser ControlSigLockedCav.pdfControlSigCavLocked2.pdf
          Reply  Mon May 10 15:41:41 2021, rana, Update, PSOMA, Cavity locking, feedback to laser 
Message ID: 2713     Entry time: Tue Apr 27 19:37:49 2021     Reply to this: 2715   2731
Author: shruti 
Type: Update 
Category: PSOMA 
Subject: PDH error signal 

Attachment 1: PDH error signal with monitor flashes

Using the setup shown in Attachment 3 (diagram here) (cavity design here), where the RF output of the free-space 1811 photodiode is sent to a Level 17 mixer ZFM-3H-S+ and then to a low pass filter SLP-1.9+ (cut-off at 1.9 MHz), I observed the PDH error signal on an oscilloscope while scanning the temperature.

Attachment 4 is a single-shot measurement of the error signal.

EOM: MPX-LN-0.1 driven with -5.8 dBm at 33.59 MHz using the OCXO pre-amp EOM output at 30 dBm attenuation.

LO: Driven at 33.59 MHz using the LO output of the OCXO pre-amp with no attenuation, estimated to be ~13.8 dBm.

The power levels of the OXCO outputs were the peak powers calculated by the Moku while observing the spectrum. The Moku itself produces a lot of distortion (many prominent harmonics were seen) while measuring this spectrum, these harmonics were less prominent when the scale was changed or when the input was attenuated sufficiently.

Attachment 2:

Picture of beat note measurement between North and Teraxion requested by Rana.

Attachment 1: PDHerrorsig.mp4  2.935 MB
Attachment 2: BeatNX20210427.pdf  16.833 MB  | Hide | Hide all
BeatNX20210427.pdf
Attachment 3: IMG_0215.jpg  1.321 MB  | Hide | Hide all
IMG_0215.jpg
Attachment 4: PDH.pdf  19.244 MB  Uploaded Tue Apr 27 20:53:38 2021  | Hide | Hide all
PDH.pdf
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