Sheila, Daniel, Nutsinee

Looking at the data taken on Nov 6 with the full interferometer, we have less than 2dB of squeezing (at high freq) with an inferred phase noise of 200 mrad. 

I didn't write down the OPO transmission, but looking at the reflection (~input power) to the OPO the nonlinear gain produced continues to degrade. Lee was suggesting that if we plot nlg in terms of green transsmitted power we could determine if the escape efficiency is degrading as well. Those number would required some digging.

The error bar here derived from the (+-) differences nlg measured using the IR PD MON channel vs. fast channel Sheila put on the ndscope. The past measurements have been done with the IR PD channel.

Could bad phase noise be due to CLF? Homodyne says so. In the past I've made a high CLF sqz/asqz measurement with the Homodyne but we thought that worsen squeezing was due to homodyne saturation. Seeing that asqz was not effected that doesn't seem to be the case.

If we were to compared the orange and the purple data at their highest and lowest error bar, the phase noise is about a factor of 1.5 different. 120uW CLF refl was used for the high power measurement and 40uW refl was used for the low CLF power measurement. The phase noise difference between the two is expected to be sqrt ratio of the sideband power, sqrt(120/40) = 1.5. 

For the IFO, we have 25mW hitting the OMC PDs (correct me here if I'm wrong). 5uW CLF transmission at 120uW input, a factor of 100 attenuation by the OMC at 3MHz, we have  ~1/sqrt(2500/(5/100)) = 4mrad expected.

To check if the source of this 200 mrad phase noise in the interferometer actually comes from CLF (or to see if it is at least partially responsible), one probably should take another set of sqz/asqz measurement now that we have lowered the CLF power input to the IFO by a factor of 2 (alog53107). If CLF was some how responsible, we should see about a factor of sqrt(2) decrease in the inferred phase noise.