Optics for laser rasters

Abstract
A number of instruments use rasters generated by deflecting one or more laser beams with some scanning device. Optics for shaping and manipulating these beams are described, with particular attention to the dual role of each element in terms of the (instantaneous) beam and the scanned pattern. A solution is shown to the problem of chromaticity in diffraction scanners. Specific examples are drawn from the scanning laser ophthalmoscope, a scanning instrument using two lasers with real-time TV display.