Change in the wavelength of light radiation stored within an optical resonator by means of an acoustic pulse

Abstract

Theoretical and experimental studies on interaction between a single acoustic pulse propagating along a glass cylinder and a whispering gallery mode light radiation in an optical resonator formed in a barrel-shaped region of the cylinder are presented. It is shown that the acoustic pulse can change significantly the resonator sizes, eigen frequencies, and position in the cylinder. Two alternatives are considered. First, the acoustic pulse, having traveled through the resonator, alters the wavelength of light radiation stored within it. In this case repeat acoustic pulses can change the light radiation additionally. Second, the acoustic pulse forces the light radiation out of the resonator and moves it in other regions of the cylinder. If the cylinder diameter decreases gradually in the regions, the light radiation is compressed and its frequency increases. As a result, a significant wavelength shift can be obtained. Results of measurements of the wavelength shift of a light radiation stored in a barrel-shaped region of glass cylinder under action of a single acoustic pulse are presented.