Abstract: A tunable time plate device for providing a continually adjustable time delay between two linearly polarized laser pulses .omega..sub.1 and .omega..sub.2. The device comprises a time plate made of a parallel flat birefringence crystal having a principal axis of refractive index n.sub.z parallel to its surface, and a principal axis of refractive index n.sub.x having an angle .phi. to its surface normal. The time plate is rotatably mounted such that it is rotatable about its n.sub.z principal axis for tuning a time delay between the two laser pulses as they travel through the time plate which is a function of an incident angle .theta. between its surface normal and the propagation direction of the laser pulses. The time delay therefore can be continually adjusted by rotating said time plate to change said incident angle .theta..