Possibility of using the interaction of acoustic and light waves in optical fibers to generate short light pulses

This article discusses optical resonators based on optical fibers whose indices of refraction are periodically modulated at frequencies smaller than the frequencies of the optical signals by a factor of 10⁵ to 10⁶. When the modulation period is equal to the time for a complete circuit of the fiber at the velocity of light, short light pulses are generated in the fiber with a carrier frequency higher than the frequency of the exciting cw optical signal.