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Entry  Thu May 20 21:50:35 2010, tarac, Laser, Laser, PMC is almost ready to be locked 
    Reply  Mon May 24 09:56:19 2010, rana, Laser, PMC, PMC is almost ready to be locked 
       Reply  Mon May 24 19:30:15 2010, rana, Laser, PMC, PMC is almost ready to be locked 
Message ID: 128     Entry time: Mon May 24 19:30:15 2010     In reply to: 127
Author: rana 
Type: Laser 
Category: PMC 
Subject: PMC is almost ready to be locked 

Quote:

You should make sure not to blow up the PMC PD: i.e. the total power on the PD out of lock should be less than 100 mW. The beam size on the PD should also be ~0.5 mm diameter with the actual beam waist being more like 0.3 mm dia.

PD should also be tilted by ~30 deg from normal incidence and the reflection dumped. Its OK if the RF output saturates somewhat at the peak of the PDH signal, but the in-lock RF level should be below ~50 mVrms into 50 Ohms.

 The power is small, our laser is 100 mW. The power on the PD is not saturated. Right now it's receiving ~10mW. It's tilted a bit and the reflected beam is blocked appropriately.

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