Abstract: An electro-optical modulator/deflector including electro-optical material and an electrode pattern arranged in response to a voltage supply to provide an electric field in the material to influence the deflection of a light beam at the moment of total internal reflection, and at least one further electrode arranged such that on application of a high voltage between said further electrode or electrodes and said electrode pattern there is in use generated within said electro-optical material in the region of said electrode pattern a phase change in the wavefront of the light beam in a sense opposite to the phase change caused by an inherent diffraction grating effect of the electrode pattern.

Abstract: An electro-optic modulator/deflector for use with a light beam comprising at least two wavelengths of light including an electro-optical material and an electrode pattern adjacent a first surface of said material arranged in response to a voltage supply to provide an electric field in the material to influence the deflection of the light beam at the moment of total internal reflection at the first surface. The light beam is divided into its constituent wavelengths which are directed to different parts of the first surface, the electrode pattern comprising interdigitated electrodes arranged so as to modulate separately the different wavelengths by predetermined respective amounts.