Yuhang and Michael

We checked the output of green power vs injected infrared for the new OPO. A variable ND filter was placed along the path and then the power meter was used just before the OPO for IR and just after for green. Figure 1 shows the IR vs green profile and the efficiency of green generation. Note that the efficiency is P_green/P_IR^2. In Matteo's thesis figure 5.7, the efficiency of a PPKTP SHG IR to green conversion is found to be about 2.3 /mW, vs 0.4 /mW here. But, we are using an OPO cavity with an incoupling mirror that has 20% reflectivity for green, whereas an SHG cavity should be completely transmissive for green.

For whatever reason, the power reading with the variable ND filter in place didn't seem very stable. But when we removed it to do a couple of high power measurements, it was more stable.

The green beam shape also looks good (figure 2).