Progress in SHG

Since we found a spare PSD in TAMA, we used that PSD to make the alignment of the crystal optical axis with the beam. We changed the stage under the SHG housing, for two reason: take less space, let the center of the crystal to be the exact the same height with the beam. With the available component in TAMA, in the attachment I put the picture of the present stage we made. At first step, we use the PSD to get the total power and the power in two directions. Then put the SHG housing on the new stage, but with 180-degree turning compare to the final position of the housing, in this way we can make sure that the beam really goes along the optical axis of the crystal. After getting almost the same power value compared to the first step, which means the crystal has been put into the right position, we installed the miniscope, try to find some modes. But finally we found out we need to lower the miniscope to get better result,the reduce of the height probably can be finished in NAOJ. So the question for now is how much we want the engineer to make the reduction. For now we have two kinds of spacer,one is 50 micrometer, the other is 150 micrometer.