Telescope installed for green and infrared

Today we received the optics we need so we started to install the telescope for both infrared and green path. Since green is easier to see and two beam are more or less superposed at the 2inch mirror, so we use the green for the reference.

Then we started to installed the 150mm and 175mm lens at the calculation place with rails and moved a little bit along the rail to make the beam have a good size at the 2inch mirror.

For the green path, we tried to remount everything. But according to my calculation, the first lens should be at 7.5cm from the cavity output, but we discovered today, the limited we can do is 8cm, cannot get closer because of the screw of the dichroic mirror. So we put it at 8cm, and did the simulation again, the result shows below,

L1: z=8cm f1=100mm
L2: z=49cm f2=200mm
L3: z=117cm f3=1000mm

In the order of L1, two dichroic, Faraday Isolator, half-wave plate, L2, L3, Faraday Isolator, half-wave plate, we put all of them and align the beam again. During the installation, one problem is that the third lens is very close to one mirror, and also there is an aperture very close to this mirror, so we put another aperture firstly just after the previous one but provide enough space for the rail of the lens.

Then we tried to measure both the green and infrared beam with the beam profiler, did some adjustment to have the size we want(1mm in radius). But the infrared beam looks have some astignatism. Checked the beam at 290m target, the green is larger than the infrared, and also there are two green beams, one is larger, one is smaller but more circular(pic 1), we tried to move the picomotor of BS to make this two green beam superpose(pic 2). The infrared is much smaller(pic3), when it moves to some position of the target, it looks good.