To check the alignment of green from OPO at GRMC, I put a PD at GRMC reflection for green from OPO (Fig. 1). The cursor 2 at 11.2mV shows the offset. Fig. 1 would show the green alignment to OPO is fine.
Then I measured nonlinear gain with BAB maximum. After some alignment of green to OPO, nonlinear gain with 25 mW green reached 5. This is consistent with theoretical nonlinear gain of 5.1 with 80mW OPO threshold, but lower than 6.8 which is the value one year ago in elog2577. The current setting is as follows.
green power (mW) | 0 | 25 |
OPO temperature (kOhm) | 7.13 | 7.13 |
p pol PLL frequency (MHz) | 230 | 160 |
BAB maximum (mV) | 286 | 1420 |
Nonlinear gain | 1 | 5 |