R&D (FilterCavity)
NaokiAritomi - 21:50, Tuesday 30 July 2019 (1532)
Loss between OPO and homodyne

[Aritomi, Yuhang]

We measured loss of each optics between OPO and homodyne BS. We put BAB on resonance of OPO by hand and measured power. The result is as follows.

position power (uW)
after OPO 231
after dichroic mirror 222
after 100mm lens 220
after PBS 219
after 3 mirrors 219
after 150mm lens 216
after HWP 215
before homodyne BS 215

Loss between OPO and homodyne is 7%. 4% is from dichroic mirror and 3% is from two lenses. According to spec of dichroic mirror (HBSY11), reflectivity for s pol should be 99.3%. We can try to optimize the angle or try another HBSY11. Anyway we need low loss dichroic mirror and superpolished lenses.

According to spec of dichroic mirror (HBSY11), reflectivity for s pol should be 99.3%. We need low loss dichroic mirror and superpolished lenses.
Images attached to this report
1532_20190730145111_32.png