Week 6 Day 1 & 2

Published on: Tue Jul 12 2011

Recently I decided to stop writing daily updates. Writing daily reminded me that at times it is better to have a long term view. Holding a thought for about a week before moving forward and acting on it suits my pace of idea generation. This gives me time to thoroughly examine the idea and look for flaws in it. The past weeks thoughts have focused around whispering gallery mode resonators.

One of the publications has a chart showing pump transmission power vs frequency. I wanted to make an arrangement so I could take similar measurements. After speaking with Professor Metcalf he suggested using an AOM to change the frequency of light, and to use a quarter wave plate to rotate the polarization, so I could separate the two frequencies (the light travels through it twice, in the schematic). After the AOM the light should pass through a resonator, and it should peak when the frequency is one of the modes of the resonator. Ideally I would like the resonator to be a whispering gallery mode resonator, but at the time I do not have one. Alternatively I could use a Fabry-Perot resonator, which I think I will do for initial testing. 

I was reading about the fabrication of WGMR, and I think it would be possible for me to construct some out of silica glass, using my lampwork glass shop. If I can learn how to measure the modes of the FP, then I could make several WGMR out of glass, at different sizes and slightly different shapes. Then I could use the WGMR instead of the FP.

A thought just occurred to me, I want to measure the frequency of the light and simply knowing the intensity is not enough. Could I calculate the frequency of the output light from the AOM? Should I interfere the two beams at some point to see what the frequency difference is? I can look up the process 'hetrodyne' for additional information.