R&D (FilterCavity)
YuhangZhao - 17:22, Thursday 10 June 2021 (2564)
homodyne LO intensity may have long term change

Aritomi and Yuhang

In the past few weeks, we measured homodyne shot noise few times, we found the shot noise level changes from -133.2dB to -133.7dB.

We monitor the BAB intensity for almost one hour on Monday this week. We found BAB intensity changed by about 5% during this time (attached figure 1). By doing 20*log10(sqrt(1.05))-20*log10(sqrt(1)), we found this can introduce 0.2dB shot noise change.

Although BAB and LO both come directly from main laser, this is not a test done for a real LO. We decide to check the power of LO before and after IRMC soon.

Images attached to this report
2564_20210610102255_wechatimg141.jpeg