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NaokiAritomi - 13:43, Thursday 01 August 2019 (1538)Get code to link to this report
OPO escape efficiency

BAB before OPO is 114.5 mW and BAB after OPO is 0.231 mW, so current transmissivity of OPO is 0.2 %. When transmissivity of incoupling mirror is T1 = 8 % and transmissivity of HR coating of PPKTP is T2 = 0.025 % and round trip loss inside OPO is L, we can get L = 12 % by solving following equation.

T1*T2/(1-sqrt(1-T1)*sqrt(1-L))^2 = 0.002

Escape efficiency = T1/(T1+L) = 40 % which is very low.

If L = 0.425 % like Marco's thesis P.87 (transmissivity of HR coating of PPKTP is 0.025%, not 0.25%), escape efficiency is 95 %.

Comments related to this report
YuhangZhao - 19:35, Thursday 01 August 2019 (1541)

I checked the website of KTP company(RAICOL crystal), the substrate absorption loss should be 100ppm in our case.

YuhangZhao - 14:30, Thursday 22 August 2019 (1556)

From Marco thesis, the escape efficiency is 0.92/(0.92+0.00425). It is 99.5%, it seems fine in that case.

NaokiAritomi - 14:59, Thursday 22 August 2019 (1557)

Escape efficiency is T/(T+L) where T is transmission of output coupler and L is intra cavity loss. So escape efficiency should be 0.08/(0.08+0.00425) = 95%. Calculation in Marco' s thesis seems wrong.