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Entry  Thu Sep 24 21:04:15 2009, Jenne, Update, MOPA, Increasing the power from the MOPA 
    Reply  Sun Sep 27 12:52:56 2009, rana, Update, MOPA, Increasing the power from the MOPA Picture_3.png
Message ID: 2007     Entry time: Sun Sep 27 12:52:56 2009     In reply to: 2000
Author: rana 
Type: Update 
Category: MOPA 
Subject: Increasing the power from the MOPA 

This is a trend of the last 20 days. After our work with the NPRO, we have recovered only 5% in PMC trans power, although there's an apparent 15% increase in AMPMON.

The AMPMON increase is partly fake; the AMPMON PD has too much of an ND filter in front of it and it has a strong angle dependence. In the future, we should not use this filter in a permanent setup. This is not a humidity dependence.

The recovery of the refcav power mainly came from tweaking the two steering mirrors just before and just after the 21.5 MHz PC. I used those knobs because that is the part of the refcav path closest to the initial disturbance (NPRO).

BTW, the cost of a 1W Innolight NPRO is $35k and a 2W Innolight NPRO is $53k. Since Jenne is on fellowship this year, we can afford the 2W laser, but she has to be given priority in naming the laser.

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