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Entry  Thu Apr 14 17:30:18 2016, ericq, Update, General, PLL measurement ongoing 
    Reply  Fri Apr 15 03:02:44 2016, ericq, Update, General, New AUX laser measurements aux_innolight_freqPSD.pdfaux_innolight_AMPM.pdfaux_innolight_data.zip
       Reply  Fri Apr 15 18:35:57 2016, gautam, Update, General, New AUX laser measurements PSL_AUX_TEMP_SCAN.pdfPSL_AUX_TEMP_SCAN.mat
          Reply  Fri Apr 15 23:11:49 2016, gautam, Update, General, Innolight 1W moved to SP table 
             Reply  Mon Apr 18 00:29:00 2016, gautam, Update, General, Beam profiling + injection current scan 6x
Message ID: 12077     Entry time: Fri Apr 15 03:02:44 2016     In reply to: 12076     Reply to this: 12078
Author: ericq 
Type: Update 
Category: General 
Subject: New AUX laser measurements 

The free running PSL+AUX beat frequency noise spectrum has been measured via PLL. AUX laser PZT PM and AM responses were measured too. 


Rough notes about these measurements:

Laser -> QWP -> HWP -> PBS -> 10% BS -> Beat
3.4Vpp out of PD, (40% contrast)
20dB Coupler, output to analyzer, coupled output to Mixer (-a few dBm, didn't check specifically)
Mixer: ZP-3+, BLP-5.1 at output
LO: OCXO @ 36MHz 13dBm->5dB Att-> +8dBm LO at Mixer

Got ~65mVpp out of Mixer

Mixer out -> SR560, LP 3Hz, G=500 -> Pomona Summing node -> Laser PZT
~30kHz UGF ~30 deg phase

Spectra, OLG via SR785 taken with free running PSL, anthropomorphic temperature servo. Data sheet calibration used for PZT. SR560 output noise dominates over analyzer, mixer, PD. Spectrum looks ok, I think.

PM measured with AG4395. High impedance probe used for laser PZT, otherwise couldn't lock. PM calibrated via mixer voltage span for fringe-to-fringe. 

PSL beam blocked, AUX power increased to read 8.0V, AM measured with AG4395.

AM/PM doesn't look to dissimilar to old measurements on wiki. ~230kHz looks like a fine modulation freq. 

Still to be done to AUX laser:
- joint PSL/AUX temperature sweeps
- Output power vs. diode current
- Beam profile

Attachment 1: aux_innolight_freqPSD.pdf  44 kB  | Hide | Hide all
aux_innolight_freqPSD.pdf
Attachment 2: aux_innolight_AMPM.pdf  92 kB  | Hide | Hide all
aux_innolight_AMPM.pdf
Attachment 3: aux_innolight_data.zip  292 kB  Uploaded Wed May 4 15:36:05 2016
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