Abstract: A rapidly tunable laser system which is operative to tune the laser beam emission to a predetermined wavelength in accordance with the polarization state thereof is disclosed. The laser beam emission may be tuned between predetermined wavelengths as rapidly as it can be altered between polarization states. More specifically, the laser system includes a polarization modulator for modulating the radiation beam emitted from a laser cell between at least two polarization states, and at least two diffraction gratings which are uniquely and fixedly aligned to specularly reflect and retroreflect radiation incident thereupon. The retroreflected radiation is of a wavelength uniquely identified with the angle of incidence of the corresponding diffraction grating.

Abstract: An electro-optic modulator for phase modulating a high power beam of monochromatic electro-magnetic radiation is described where localized phase distortion occurring within the beam due to thermal heating is compensated. The received radiation is passed through two precisely matched electro-optic crystals and an optical compensating element located between the two crystals. One of the crystals has an applied field for modulation purposes. With this arrangement, the thermal birefringent effects induced in the crystals are cancelled out with the output beam polarization properties determined by the input polarization, optical compensating element and applied electric field.