Today I optimized the BAB power in transmission of the Faraday isolator by tuning both the rotation of the motorized half-waveplate and the horizontal position of the FI mount.

First I removed the Faraday isolator and I measured the optical power at the position just before the MM telescope to be 1.399+-0.003 mW. Then I placed the FI back in position, and performed the tuning with the power meter in the same position. I obtained a maximum transmitted power of 1.392+-0.003 mW.

This corresponds to a throughput loss of (0.5+-0.3)% in agreement with preliminary characterisation in optics lab.