Single- and multimode VCSELs operating with continuous relief kinoform for focussed spot-array generation

Abstract
We report the use of both single- and multimode VCSELs operating at 850 nm as the illumination source for a continuous-relief diffractive optical element (DOE) fabricated in resist on quartz. The system produces a 4/spl times/4 array of focussed spots from a single optical input. The uniformity error was found to be /spl sim/10% in all cases, and the overall system efficiency /spl sim/35% A single spot-coupling efficiency of 70% into a multimode fiber placed 20 mm from the DOE was also measured.