Abstract: This device comprises a photoelastic interaction medium between an incident light beam (28) and at least one acoustic or sound wave, as well as means (4, 6) for producing the acoustic or sound wave. The interaction medium is a superlattice (18), which is transparent to the light beam and whose period is close to an integral multiple of half the wavelength of the light beam in the superlattice.Application to the production of acousto-optical deflectors and modulators.

Abstract: An optical beam modulating device used for recording halftone plate duplicate images on a recording material including two multi-channel optical beam modulators, each including a rectangular parallelepiped modulator crystal which has a prescribed number of acoustic electrodes installed on one side surface. The electrodes are installed at equal pitch intervals so that Gauss beams can be directed across the electrodes separately from each other, and the positions at which the electrodes of one modulator are installed are shifted by one-half pitch with respect to the positions at which the acoustic electrodes of the other modulator are installed.

Abstract: A laser beam scanning system is used as a laser probing apparatus. The apparatus includes an acousto-optic modulator provided on an optical path for intensity-modulating a laser beam in accordance with an input signal, a beam intensity control device for measuring a beam intensity distribution of the laser beam incident on a wafer surface, for correcting the input signal to the modulator as a result of measurement, and for making uniform the laser beam illumination distribution over the wafer surface, and a device for measuring an electrical variation in that wafer pattern portion illuminated with the laser beam.