Participaint: Aritomi and Yuhang

Since we found PDA05CF2 (thorlabs InGAS PD) is more suitable for infrared signal. We decided to use it for OPO locking. Before we took the filter cavity locking PD for OPO locking because it has a DC channel. Since we have a better one, we decide to put this qubigPD (with DC) back for filter cavity locking.

Besides, according to simulation, the OPO reflection error signal is 5 times smaller than transmission. And we improve the error signal by a factor of 10. So in principle, now the error signal from OPO reflection should be also enough to lock OPO.