Cont'd from 17428. We also visited TMSX. The ouput viewport window was covered (Fig. 1), so I removed it (Fig. 2), and then the transmitting green beam from ETMX could illuminate the DCPD (PDA100A), QPDs, and GigE cameras (Fig. 3; taken by K. Tanaka).

Post analysis

The TMSX Gr DCPD (K1:AOS-TMSX_GR_PDA1_OUT_DQ) provides about "21.5" when the green light enters it (Fig. 4), while "10" when shut. Anyway, there seems not filters active in the corresponding filter bank. Thus I can assume this number as a raw counts. So, 21.5cnt * 610uV/cnt = 13mV. The PDA gain was set to 10dB (Fig. 5). According to the manual of the PDA, in this setting, the gain is 4.75e3 V/A, so 13e-3/4.75e3 = 2.7 uA. In the same manual, the conversion factor of the PD is about 0.34 A/W at 532nm, so 2.7u/0.34 = 8uW. According to the layout, two 50/50 BSs are inserted between the viewport window to this PD, so the total power would  about 32 uW.

According to 17240, the PD that had been in EXA caught about 11uW. Extrapolating this number to the total Gaussian beam power 11uW should be divided by 1-Exp(-2*((r/w)^2)) = 0.078, where r =5mm and w =35/sqrt(2) mm. 11uW/0.078 = 140 uW should be the estimate power amount reached in EXA. The green transmittance of ETMX is 0.06 (see wiki), 140uW*0.06 = 8.4uW... On the other hand, in (rough) theory, 10mW-green-input*(0.06)^2 = 36uW should be here.

So the green power estimation from the TMSX PD and the theory seems consistent...