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| == Suspect on mirror optical losses by H.Yamamoto == | == Concern on mirror optical losses by H.Yamamoto == |
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| * LF RMS could be improved if we spend a lot of money and time. LIGO asked for RMS<0.5nm and Tinsley. | * LF RMS could be improved if we spend a lot of money and time. LIGO asked for RMS<0.5nm and Tinsley has achieved that value. |
Concern on mirror optical losses by H.Yamamoto
Scattering loss of 45ppm by low-freq (>1mm) surface error of 1nm RMS (25ppm with 0.75nm RMS).
Scattering loss of 6ppm by high-freq (<1mm) surface error of 0.2nm RMS.
- Unexplainable punctate scattering loss of 10ppm (realistic estimate would be 15-30ppm).
These alone would make the total scattering loss already 61ppm (with 1nm LF RMS) or 41ppm (with 0.75nm LF RMS).
- Besides, absorption at the coatings, assumed to be 0.5ppm, can go worse by a few ppm easily.
LF RMS could be improved if we spend a lot of money and time. LIGO asked for RMS<0.5nm and Tinsley has achieved that value.