Abstract

One-dimensional relief gratings have been formed on a thick optical waveguide to couple the propagating light beam from waveguide to space with a desired spatial intensity distribution. The gratings are generated, considering both diffraction and geometrical optics, to have less sensitivity to the angle of incidence. The global appearance of light output from gratings is more uniform and the total efficiency over entire gratings can be improved. The economical embossing or injection molding approach can be used in process. The product can be broadly used for many lighting devices with the advantages of transparency, small thickness, and flexibility of (one-dimensional) surface curvature.

© 1992 Optical Society of America