Terry, Nutsinee
Got some measurement of the EOT faraday isolator on the green path:
Over all transmission ~ 91% (S and P pol)
Isolation ~ -26dB
Couldn't find a non-polarizing beam splitter for 532 so I used a dichroic beam splitter set at weird angle (~30 degree or so) to partially let light though. I used one of the precision photonics mirror found in the SQZ bay drawer to reflect transmitted light straight back into the faraday and measure the light that bounced back from the beam splitter. I couldn't measure the part of back reflected light that went though the beam splitter so I guesstimated the transmission knowing what came in and what gets transmitted on its way into the faraday. Terry thinks this number is disappointingly low, given the dodgy set up I'd take this number as an upper limit (in a sense that it can't get any worse). But again, given the nearly 10% loss maybe we just have a not-so-great isolator.
Correction: according to the manual here the measurement is still within the spec. The isolation is a bit low but that could be due to our dodgy set up.