[Torrey, Daniel]

We measured the reflectivity of 775 nm light on the Newport 10D20DM.8 (1550 nm HR mirror). At a 45° AOI, there is roughly a 40-50% reflection. +/- around 5° away from 45°, the reflection drops off sharply. Thus, these mirrors cannot be used to make a bowtie cavity for 775 nm light.

Low AOI: 3% reflection, 70% "transmission" but definitely a lot of this is scattered light

45°: 40-50% reflection depending on polarization, ~40% "transmission" but definitely a lot of this is scattered light