R&D (FilterCavity)
YuhangZhao - 21:52, Tuesday 11 January 2022 (2788)
Preparation for OPO internal losses measurement

Michael and Yuhang

As discussed in elog2784, we need to inject laser from OPO in-coupling mirror side to distinguish different OPO internal losses values. This is the reason of work reported in this elog. To achieve the measurement, we have done the followings:

1. Remove periscope and rotation stage for OPO

2. Prepare a 50:50 BS placing in front of OPO to extract OPO reflection signal information

3. Lower the height of OPO transmission BS, PD and camera

(these works are shown in Fig.1)

4. Confirm and adjust the flatness of laser beam after removing periscope

(this work is shown in Fig.2,3,4)

5. Put OPO in place and optimize its position by hand. Try to get a reasonable OPO transmission mode. We have found a TEM01 mode now.

Next step: Find OPO transmission signal on PD. Optimize OPO injection beam alignment.

Images attached to this report
2788_20220111135159_wechatimg762.jpeg 2788_20220111135210_wechatimg763.jpeg 2788_20220111135218_wechatimg760.jpeg 2788_20220111135227_wechatimg761.jpeg