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| 40m Log |
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 Thu Feb 5 21:42:28 2009, Yoichi, Update, PSL, My thoughts on ISS 
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 Fri Feb 6 09:52:35 2009, Kakeru, Update, PSL, Current shunt transfar function
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Fri Feb 6 23:23:48 2009, Kakeru, Yoichi, Update, PSL, ISS is fixed
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Mon Feb 9 16:02:42 2009, Yoichi, Update, PSL, PSL relative intensity noise
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Tue Feb 10 23:36:25 2009, Kakeru, Update, PSL, PA current and laser output
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Wed Feb 11 07:28:25 2009, Yoichi, Update, PSL, PA current and laser output
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Wed Feb 11 23:51:53 2009, Kakeru, Update, PSL, PA current and laser output
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Message ID: 1291
Entry time: Wed Feb 11 07:28:25 2009
In reply to: 1289
Reply to this: 1295
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| Author: |
Yoichi |
| Type: |
Update |
| Category: |
PSL |
| Subject: |
PA current and laser output |
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I think we should also plot the laser power at the MOPA output. The horizontal axis should be the absolute current value read from the PA current monitor channel, not the slider value.
This result is consistent with my hypothesis that the thermal effect is canceling the power change at low frequencies (see elog:1276).
But if it is really caused by thermal effect or not is still unknown.
I'd like to see a larger scan into the lower current region.
| Quote: | I changed the PA current and measured laser output power (monitor PD signal).
The gain of ISS is 13dB
Attached figure is the relation of PA current and the average and standard diviation of laser output.
The average of output power decreas as current increase. It looks something is wrong with PA.
When current is -0.125, 0, 0.5, ISS become ocsilating. This looks to be changed from previous measurement.
I wrote matlab code for this measurement. The code is
/cvs/cds/caltech/users/kakeru/scripts/CS_evaluate.m
This function uses
/cvs/cds/caltech/users/kakeru/scripts/moveCS.m |
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