Abstract

The ability to shape the diverging beam from a surface-emitting laser or a light-emitting diode is important for future micro-optic illumination systems. In this paper, we consider using two surface-relief diffractive optical elements (DOEs) to shape the output from a 980-nm multimode vertical-cavity surface-emitting laser (VCSEL) into a closely spaced rectangular spot array in the near field (approximately 10 mm from the laser). We also describe a similar system for illumination by an 850-nm resonant-cavity light-emitting diode (RCLED). With small intensity variation from spot to spot, the rectangular spot array is intended to approximate a profile that is completely uniform from point to point. This design strategy is particularly valuable with the VCSEL, as its complicated multimode emission profile makes it nearly impossible to guarantee absolute uniformity within the rectangle, but creating a rectangular array of light spots spaced very close together is still feasible.

© 1996 Optical Society of America