I'm setting up fiber optic so that I can send frequency stabilized laser to ATF. Right now the power coming out is small (0.8 mW from 20mW input). I'm working on better mode match for better efficiency.
Note: due to the space limitation, I cannot pick the beam after the broadband EOM used for frequency stabilized the laser. The beam is taken after the PMC, where it was used to dumped the excess power.
optical fiber: nufern pm980
modematching: The focal length of the collimator is 2.0 mm, MFD of the fiber is 8 um. The beam diameter at the lens is then ~360 um.
The coupled power is quite small. I'll check the mode matching again to get more power coming out.