Apparatus for monitoring the optical quality of a beam of radiation

摘要

An apparatus for monitoring the optical quality of a beam of coherent radiation or of an image from an incoherent source is disclosed. The apparatus includes a disk capable of being rotated, a plurality of slit sets circumferentially disposed about the disk at a radial position where each slit set includes a first and second slit disposed in an orthogonal relationship to one another and symmetrically disposed about a radius line extending from the radial position of the slit sets to the center of the disk and a third slit disposed symmetrically between the first and second slits. The slit sets are adapted for scanning a focused beam of radiation in the zero, forty-five and ninety degree direction to provide data pulses proportional to beam jitter and astigmatism. Variable positioning of successive slit sets within the axial dimension of the disk provides pulses having configurations proportional to the defocus of the focused beam.