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Entry  Mon Jun 7 19:24:04 2010, tarac, Laser, Laser, RefCav is locked 
    Reply  Tue Jun 8 03:16:21 2010, Frank, Laser, Laser, RefCav is locked 
Message ID: 151     Entry time: Mon Jun 7 19:24:04 2010     Reply to this: 152
Author: tarac 
Type: Laser 
Category: Laser 
Subject: RefCav is locked 

RefCav is locked , the beam is more stable than yesterday setup. I'll write down the values of the setting for a quick reference.

I'm not sure what universal names for all these channels are. I just explain them in more details for my future reference and next generation archeologists.

fss controller:

Common Gain(  for both fast and PC paths): 23.6 dB (fast path controls the PZT which changes the length of the NPRO, PC path controls the phase

shift of the beam)

Fast Gain ( for PC path only): 12.5 dB

Phase shift: 0 + 180 degree. ("+180 degree" means phase flip)

RF Amplifier Adj (power for 35.5 MHz sidebands): 6.28 V.

Thermal control ADj (a voltage calibrator connected to slow channel of the laser controller): -0.010V

PMC controller

Servo gain Adj (over all gain of the demodulated signal): 27.75 dB

Output DC offset (offset voltage that governs the length of the PMC): -3.12 V

Phase shift: 2.87 V + 180 degree

RF Amp Adj (power for 21.5 MHz sidebands): 5.36V.


Now I'm working on ACav path. I made a cable for a photo diode.

I'm not sure if the last PD is a working 35.5 MHz PD, I'll see if it works or not.

Now I'm using two 2-channel monitors to simultaneously see the  beams after PMC and RefCav. It will be more convenient if I use a 4 channel monitor, I'll  clear some space for it.


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