Patent ID: 7924419
Filing Date: 2011-04-12
Classification: G01N,H01S

Abstract:
1. An apparatus for reducing speckle in a beam of laser radiation, comprising: an optical scanner configured to deflect a portion of the beam by diffraction and to scan an incidence angle of the deflected portion of the beam over a range of angles using an acousto-optic transducer and a drive circuit coupled thereto, wherein the beam is a pulsed beam, and the drive circuit applies a frequency-chirped pulse to the acousto-optic transducer in synchronization with the pulsed beam to diffract a first order of the beam and to scan the deflected portion of the beam on a target plane at an angle that varies over a duration of the laser pulse; and output optics, which are coupled to direct the deflected portion of the beam exiting from the scanner so that the beam irradiates a single area of the target plane over a range of different angles, so as to de-correlate the radiation, the output optics including a lens and a diaphragm at a Fourier plane of the lens to stop an undeflected zero order of the beam from passing.