Terry, Sheila
After the squeezer fiber was replaced in November, the total transmission of the chain was 40%, but it dropped over a couple of days starting Nov 30th 45903. Terry and I went out this morning, Terry loosened and tightened the connections at the feedthrough, watching the OPO reflection (with the OPO off resonance). While we were doing this, the transmission to SQZT6 dropped by 30% (from 3.5 mW to 2.6mW) We then disconnected the fiber and measured the power. We cleaned the fiber, and the resulting transmission to SQZT6 was the same (2.6mW). We went to ISCT6 to measure the power after the first periscope mirror, and measured 2.55mW, which agreed with the calibrated channel from the reflected diode. The OPO was slightly on resonance at this time, when we pull the OPO further off resonance the reflected power went up to 2.6mW.
| mW | % | |
|
launched into fiber on ISCT6 (measured using LAUNCH diode and relying on calibration) |
20 | 100 |
| reaching chamber feedthrough (power meter) | 12.8+/-.1 | 64 |
| reaching SQZT6 periscope (power meter) | 2.55 | 12.75 |
| reaching SQZT6 diode (according to calibration) | 2.6 | 13% |
With the maximum of 20mW of power injected into the fiber, this allows us to have a nonlinear gain of 2.3.