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Entry  Wed Jul 16 01:18:02 2014, rana, Summary, LSC, Python Wavelet peak finding for dramatic ALS - Red Resonance finding speedup findRedResonance.pdf
    Reply  Wed Jul 16 01:35:16 2014, Koji, Summary, LSC, Python Wavelet peak finding for dramatic ALS - Red Resonance finding speedup 
       Reply  Mon Jul 21 17:32:43 2014, ericq, Summary, LSC, Arm losses 
Message ID: 10248     Entry time: Mon Jul 21 17:32:43 2014     In reply to: 10211
Author: ericq 
Type: Summary 
Category: LSC 
Subject: Arm losses 

Quote:

From the last plot:

- Subtracting the offset of 0.0095, the modulation depth were estimated to be 0.20 for 11MHz, 0.25 for 55MHz

- Carrier TEM00 1.0, 1st order 0.01, 2nd order 0.05, 3rd order 0.002, 4th order 0.004

==> mode matching ~93%, dominat higher order is the 2nd order (5%).

Eric: now we have the number for the mode matching. How much did the cavity round-trip loss be using this number?

Using these numbers for both arms (Modulation takes away .2*.25 = 5% power, mode matching takes away 7% after that), I get the following from my data from March:

Xarm loss is 561.19 +/- 14.57 ppm

Yarm loss is 130.67 +/- 18.97 ppm

Obviously, the Xarm number looks very fishy, but its behavior was qualitatively very different when I took the data. ASDC would change from ~0.298 to ~0.306 when the Yarm was locked vs. misaligned, whereas the xarm numbers were .240 to .275. 

In any case, I'll do the measurement again tomorrow, being careful with offsets and alignment; it won't take too long. 

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