A scanning grating technique for measurement of submicron focused spots

Many applications in optical research require the use of diffraction limited point images with reduced spot sizes. The instrumentation that evaluates these small diameter images must have high resolution (sub-micron) capabilities. One method used to measure sub-micron optical point images is a scanning grating technique. However, many characteristics of this measurement technique have not been fully examined. In this paper, the sensitivity of this measurement technique to the scanning mechanism, beam characteristics, and grating tilt is evaluated