Whispering Gallery Resonators Dispersion as Internal Temperature Reference

Whispering gallery mode (WGM) resonators are mirrorless, all-solid optical dielectric resonators capable of extremely high quality factors. The narrow line widths, small size and excellent mechanical stability of these resonators make them attractive for laser frequency stabilization. The critical issue in this application of WGM resonators is compensating the variations of the resonator material properties, which are primarily temperature related. We demonstrate a technique that utilizes the temperature dispersion of the optical materials birefringence for this purpose. By observing a differential frequency shift between the ordinary and extraordinary WGM families, we are able to measure -- and to actively stabilize -- the resonator temperature down to several nano Kelvin at room-temperature. This corresponds to a fractional frequency stability below one part in 10^13.

Date/Time: 
04/01/2012 - 17:00
Presenter: 
Dmitry Strekalov
Location: 
125 Steele, Caltech