Nick Brewer: Difference between revisions

I must have done the <math>I_r/I_{in}</math> measurement wrong on 5/21/14. Today I measured the same finesse that I got two days ago (~65.5%). I looked at the reflected signal before it went through the beam cube and got a similar measurement for <math>I_r/I_{in}</math> (5.4/7.02 = 0.769). I think the reflectivity needs to be measured once the temperature is optimized for green generation. When I did this I got <math>I_r/I_{in} = 0.239</math> (accounting for a 106 mV noise the photodiode was seeing).

I redid the mode matching calculation with g=0.953, <math>R_{in}=0.05239476</math>, and <math>I_r/I_{in} = 0.239</math>. With this numbers I get <math>m=0.759</math>. This is good because it means the cavity is mode matched pretty well, and also that the cavity must be pretty well impedance matched. If the impedance matching is perfect, I think the mode matching coefficient, m, is just <math>1-I_r/I_{in}</math>. In this case, <math>1-I_r/I_{in}=0.761</math>.