- DIFFRACTION GRATING-BASED BACKLIGHTING HAVING CONTROLLED DIFFRACTIVE COUPLING EFFICIENCY

摘要

Diffraction grating-based backlighting with controlled diffraction coupling efficiency includes a light guide and a plurality of diffraction gratings on a surface of the light guide. The light guide is for guiding light, and the diffraction grating uses diffractive coupling to outcouple a portion of the guided light and direct the outcoupled portion from the light guide surface as a plurality of light beams in the direction of the plinth. The plurality of diffraction gratings includes diffractive features having a diffractive feature modulation configured to selectively control a diffractive coupling efficiency of the diffraction grating as a function of distance along the light guide surface.