Acoustooptic modulation device capable of avoiding impedance mismatching over a wide frequency band

摘要

In an acoustooptic modulation device, a plurality of split light beams are produced from a beam splitter in response to a single incident light beam and projected onto partial modulators comprising acoustooptic mediums and transducers attached to the mediums, respectively. The transducers have different thicknesses to vary input impedances of the respective partial modulators and are supplied from an electric signal circuit with modulated electric signals falling within frequency bands different from one another, respectively. Preferably, modulated light beams are produced from the partial modulators through an optical system to be focussed into a predetermined geometric arrangement. The beam splitter may be a body having a pair of parallel surfaces covered with reflection and semitransparent layers, a diffraction grating, or a fiber grating.