Patent ID: 6922497

Claim:
A method, comprising: optically coupling first and second optical resonators to allow for light coupling from the first optical resonator to the second optical resonator, wherein each optical resonator is configured to support whispering gallery modes, and wherein at least one of the first the second optical resonators is formed of a radiation-sensitive material which has a refractive index changes in response to a radiation beam at a wavelength different from light in the whispering gallery modes; coupling a monitor beam through the first and the second optical resonators to produce an optical transmission beam; exposing the one resonator formed of the radiation-sensitive material to the radiation beam to modify the refractive index of the resonator; optically controlling the exposure of the radiation-sensitive material to the radiation beam to separate a change in the refractive index caused by a permanent change from a temporary thermal change in the radiation-sensitive material; monitoring a spectrum of the optical transmission beam to measure a line shape of the spectrum; and terminating the exposure to the radiation beam when the line shape is changed to a desired line shape.