R&D (FilterCavity)
YuhangZhao - 22:28, Friday 02 August 2019 (1546)
Injection and reflection telescope for SQZ into filter cavity

Recently we have some worry about squeezing measurement about losses(entry 1532). Although we have the main worry about OPO intra-cavity loss, we also want to replace the normal lens we are using with the super-polished lens from CVI company.

I checked the simulation of Eleonora Polini(entry 1311), there are some discrepancies.

According to these difference, I did the calculation again. The distance(from bench to waist close to 2-inch mirror) is estimated as attached in Figure 1. This is only an approximation. But since it is a very collimated beam, I think it is fine. In this approximation, the black number is provided by Yuefan and Eleonora (entry 1133) while the purple number is calculated according to these number. The distance is estimated by the holes on the bench (2.5cm between two holes). The distance on the bench is summarized as follows:

With this distance information and new database, I simulated again the telescope. I tried to choose the result based on the already bought lens from CVI.

The result is attached in Figure 2 and 3. In this case, we are using PLCX-25.4-149.9-UV and PLCC-25.4-515.1-UV for injection. And we are using PLCX-25.4-124.9-UV and PLCC-25.4-51.5-UV for reflection. The lens in the red color we have in the lab.

Images attached to this report
1546_20190802150304_113320181203113944chamber.png 1546_20190802152839_10.png 1546_20190802152848_10.png
Comments related to this report
EleonoraPolini - 00:57, Thursday 22 August 2019 (1555)

I was using a database considering all the focal lenghts commercially available, not only the ones on Thorlabs. Did you check also the robustness of the injection telescope with the two lenses that close?

The last version of injection telescope was version 3 of entry #1366.