I took four high power single bounce OMC scans, with 50W and 60W input into the IMC. The goal was to confirm the mode matching at high power is still correct in the IMC. I took scans using ITMX and ITMY aligned to also confirm there are no differences in the mode matching on each ITM as well. See alog 62828 for more details on the scans. The most important notes: for all scans the RF9 mod depth was set at 23 dBm and RF45 was set at 26.8 dBm and the 60W scans also had carrier saturation (at 70 mA DCPD sum, we expected 80mA at this power). As discussed before, the DCPDs themselves can handle high power, but the ADC saturated. At 50W input, the carriers had ~67mA DCPD sum, so I believe anything higher than 50W input is likely to saturate.

At 50W X and Y the modulation index for RF9 is 0.218 and RF45 is 0.278. These line up with the values calculated at 10W for the same modulation depths. The calculated modulation indexes (indices?) at 60W are artifically higher due to the carrier saturation. However, the modulation index for the 20 carriers and sidebands at 60W match the same for the 20 in the 50W scan (RF9=0.23 and RF45=0.28). The ratios from the 00 to 20 of the 50W scan indicate that mode matching is at ~96% for the IMC.

The next steps for all recent OMC scans are to fit the peaks. More to come...