Laser beam phase measurement and control system

摘要

An intensity measurement system portion of a phase measurement and control system permits rapid measurement of the laser field intensity profile in the transverse plane of a main laser beam. The intensity measurement system portion measures the laser field intensity profile by measuring the intensities of a plurality of beam samples of the main laser beam. The aforementioned measured intensities are processed in a phase computer according to a predetermined algorithm to generate drive current profiles in response to the phase variations of the main laser beam. These drive currents a dither-control amplifier which causes electromechanical movement of a plurality of mirror segments of a multi-dither mirror to correct for the random phase variations in the main laser beam. An important consideration in configuring the intensity measurement system portion of the present invention is the use of a reflecting stop and a reflecting stop detector combination to obstruct one of the plurality of beam samples and to measure the intensity thereof at the reflecting stop position.