The DC output of the PDH detector on ISCTEY seems low, so I went to measure the power on the PD.  The power meter says 2mW.  The detector gives 17mV at the output, and it seems that the PD has 10 Ohm transimpedance with a gain of 5 and a responsivity of 0.3A/W at 532nm.  17mV / (5 * 10 mV/mA * 0.3 mA/mW) = 1.1mW, which is in the ballpark.  The coupling efficiency is probably not good enough to achive 0.3A/W, so that might explain some of the discrepency... in any case, the real mystery is why we have only 2mW on the PD.