[Craig, Sheila, Elenna]

Craig and I took a single bounce scan (plot with pzt) at 10 W input (alog 62531). I calibrated the time axis of the scan to frequency in MHz using 10 identified modes: both carrier00 modes, the lsb and usb 9 and 45 MHz peaks, as well as the carrier10 and carrier20 peaks. I used an OMC FSR of 264.81 MHz and higher order mode frequency of 57.825 MHz (an average of the horizontal and vertical transverse mode spacing from Koji Arai) to calculate the known frequencies of these modes, and fit time to frequency with a sixth order polynomial fit (figure).

With a calibrated frequency axis, I proceeded to fit and find the 118 MHz 00 sideband, as well as all first and second order sidebands. I also search for all carriers and 9 MHz sidebands up to 9th order, and the 45 MHz side bands up to 3rd and 5th order. Some of these are indistinguishable from lower order modes, and those particular modes, their orders and frequencies are listed in the results file. I also calculated the power ratios to the carrier for the 00, 10, and 20 modes. Finally, I calculated the RF9 and RF45 modulation depths. The RF9 modulation depth is 0.21 and the RF45 modulation depth is 0.269.

All of these results are listed in the text file OMC_single_bounce_modes.txt

The MATLAB code I wrote to calculate this lives in https://git.ligo.org/aligo_commissioning/labutils/-/tree/master/omc_scan/Matlab