Abstract

A new method to introduce a variable temporal delay of ultra-short light pulses with the help of a birefringent crystal is proposed and studied. Variation in the propagation velocity difference between the ordinary and extraordinary waves in a birefringent crystal that comes from change of crystal's optical axis orientation with respect to incident light beam makes it possible to implement a compact delay line for ultra-short pulses, based on a swinging birefringent plate. Variation of temporal delay At between the ordinary and extraordinary components of light pulse inside a birefringent crystal of thickness d when it gets turned by a small angle Q. with respect to Z axis is given by the following linear approximation: where c is the speed of light in vacuum, n_o, n_e are the principal refractive indices of the ordinary and extraordinary waves, θ is the angle between the ordinary wave vector and the prin­cipal plane of the crystal.

© 2000 IEEE