Supression Of Laser Beam Amplitude Modulation Due To Acoustic Beat Waves In Multiple Frequency Bragg Acousto-optic Deflectors
Original Publication Date: 1979-Nov-01
Included in the Prior Art Database: 2005-Feb-20
Acousto-optic beam deflectors. when operated with two or more simultaneous acoustic frequencies exhibit amplitude modulation of the deflected optical beams. The source of this modulation is due to the light beam interacting with modulated acoustic waves which exist in the solid. These modulated waves are the result of superposition of the separate acoustic waves in the modulator material. When acousto-optic deflectors are used as beam intensity modulators as in electrophotographic printers using laser exposure, such additional amplitude modulation is undesirable. This modulation may also be undesirable in other applications using acousto-optic scanners as addressing elements for optical beams.