[Daniel, Torrey]

-Going to move AOM frequency to calibrate offset from 1550 nm light to 775 nm light.

Frequency Generator at 80 MHz: 101 uW at fiber output to OFC

Frequency Generator at 78 MHz: 130 uW at fiber output to OFC

We remeasured the required shift at 80 MHz. Screenshot attached. Shifted to 78 MHz AOM shift. and measured the required shift.

78 MHz, fiber input power: 500 uW

Calculated that 1550 nm and 775 nm resonances through cavity would align with a phase shift of 59 MHz (modulo ~31-33 MHz); can't go to 92 MHz with the Siglent signal generator (max 80 MHz)

:After shifting AOM input frequency to 59 MHz, realigned mirror back into AOM and fiber coupler.

240 uW into fiber, 74 uW out. The AOM is less efficient at 59 MHz according to the spec sheet and in this data. Checked alignment of modes in frequency space. Seems to be an error in the calculation (about a factor of 2). Going to increase frequency past 80 MHz instead of going lower, because the efficiency drops off significantly below ~45 MHz according to the specs.

We need to use a different signal generator to go to the calculated 104 MHz signal required to make the 775 nm and 1550 nm transmission peak align. We strung up a cable to use the moku as the signal generator for the AOM. We aligned the 104 MHz beam into the fiber, optimized the frequency of the AOM to 104.37 MHz to align the peaks.

After this we have confirmed 775 and 1550 light are resonant in the cavity at the same time.

We placed the 775 nm light approximately halfway on the 1550 nm light, locked the cavity on the 775 nm light using the laser frequency, and then observed the drift of each wavelength's cavity transmission over time. This drift occurs if the 1550 nm wavelength changes over time relative to the 775 nm wavelength. Attached are two time traces of the logged data of the 1550 nm and 775 nm cavity transmission.

Separately, we also have a measure of the transmission peaks while scanning the laser frequency with a triangle wave with a 10 Hz frequency to calculate the different finesse for each wavelength, will update.