Nick Brewer: Difference between revisions

Once the cavity was tuned and the temperature was adjusted to be at the optimal value, we measured 5.5 mW of green (I'm almost positive we used the right wavelength settings on the power meter). The input power was ~45 mW. That is an efficiency of ~12%. If I take <math>\eta=1.01/1.21</math> \rightarrowso that <math>I_R/I_{in}=0.165</math> and figure out the mode matching coefficient with the other measured values above, I get m=0.84 (very well mode matched...almost too well). If there is 45 mW of power before the cavity, and the mode matching coefficient is 0.84, that means that 36 mW of power is being coupled into the cavity. When I ran the Matlab code I wrote to simulate the cavity enhancement, I find that for and input coupler with T=0.05, we should expect ~12% efficiency. This result is so close to what we measured that I almost certainly calculated something wrong. If I use <math>I_R/I_{in}=1.01/1.21=0.83</math>, I get a mode matching coefficient of m=0.12, which corresponds to 5.4 mW getting coupled into the fiber, which is less than the green power we got out.