Infrared beam when cavity is locking with green

At the same time when we did the measurement, we installed another high reflective green mirror on the infrared path, since when cavity is locked, the green beam is much more powerful, one mirror is not enough to get rid all of the green on the infrared path.

After installed this mirror, the infrared became even weaker than before, I took a picture (pic 1)but it maybe too dim to see it. So when the cavity is not locked, we still can see the two infrared beam is flashing.( We are not sure why we can see two infrared beam very close to each other on the screen, maybe because some reflection between the two mirrors. ) When the cavity is locked the two beam both got stable. We tried to cut the infrared on the bench and we are sure what we saw is the infrared.

Then we tried to take a video of the infrared when the cavity is locked. This is the video: https://www.dropbox.com/s/gvsj0lsoei1pmqa/VID_1.MOV?dl=0

So this is the video I took when I asked Marc to jump in the central room, so you can see there are two beams moved to each other in the video.