Patent ID: 7274718
Filing Date: 2007-09-25
Classification: G02F,H01S,H04N

Abstract:
1. An arrangement for electronically aligning a laser beam with an acousto-optical modulator (AOM), comprising: a) means for directing the laser beam at an incident angle relative to a longitudinal axis of the AOM for exit from the AOM as a zero order beam having a beam intensity; b) an acoustic drive for conducting to the AOM an acoustic drive signal having a drive amplitude and a drive frequency to generate in the AOM a plurality of acoustic planar waves for deflecting and diffracting the laser beam incident on the AOM as a first order beam having a beam intensity at a deflection angle relative to the longitudinal axis; and c) means for electronically adjusting the incident angle to be a Bragg angle for diffraction efficiency, including a detector for detecting the beam intensity of at least one of the order beams, and for electronically changing the drive frequency of the acoustic drive signal and, in turn, the Bragg angle as a function of the beam intensity detected by the detector, the detector being operative for detecting the beam intensity of the zero order beam and stops changing the drive frequency when a minimum of the beam intensity of the zero order beam is detected.