Acousto-Optic Spectral Filtering of Femtosecond Laser Pulses

A programmable coherent filtering of a femtosecond laser pulse can be performed by a longitudinal acousto-optic interaction between the light pulse and a programmable acoustic waveform that describes the impulse response of the filter. Since the ratio between the speed of sound and the speed of light is of the order of 10−7, coherent control of the optical pulses can be performed with electrical signals in the tens of megahertz range.