SHG and temperature controller turned on and we are seeing 775 nm light (probably). Couple of things:
1) The thorlabs power meter doesn't have a 775 nm light calibration, if we want to detect 775 we may want to find another power meter. The closest it has is 830 nm.
2) SHG temp controller takes ~350 seconds to stablize to within .005 of a degree. Set it to 50.461 C for maximum 775 effeciency.
3)The SHG cavity it wildly inefficient at low input powers, it produces 38.5 uW of 775 with an input of 28 mW (.13% effeciency, also for the record 4 uW measured at 1550 as well). I ramped the current on the amplifier to 1A. This corresponds to an input power of 93 mW which yields an output of 150uW (.16% effeciency). The SHG has been assigned the serial number S2300012, see that link for specs and manual for this which has an efficiency curve as a function of input power. Similarly for the temperature controller S2300013.
We also need a more permanent way to mount it to a breadboard if anyone wants to 3D print something for it.
Daniel, Torrey, and Sander
To measure the power out of the SHG, we are using a Thorlabs S132C without the ND filter on. We measured the output of the SHG before and after reflection at a 45° AOI off a Thorlabs BB1-E03 mirror. The BB1-EO3 reflects p-polarized 775 nm light at 99.2 and 1550 nm light at 7.0%. There was no noticible change in the power before and after reflection, indicating very little 1550 nm was transmitted out of the SHG. To measure the 775 nm power from the SHG, we set the S132C to 700 nm and 830 nm. Using the given responsivity (mA/W) specs as a function of wavelength, we can convert the given power at these selected wavelenghts to 775 nm power. For a setting of 830 nm, multiply the given power by 1.41 to get the 775 nm power. For a setting of 700nm, multiply the given power by 0.54 to get the 775 nm power. Doing this gives 1.59 mW and 1.61 mW, respectivly, for infered 775 nm power. We were expecting around 5 mW for a 200 mW input based on the SHG specs, but the graph is difficult to read. Further analysis is needed.