Cross talk and optical efficiency of an energy-harvesting color projector utilizing ceramic phosphors.

Abstract

A color projector screen was fabricated by filling three kinds of ceramic phosphor powders in the periodic hollow columns formed in a ${50}\\;{{\\rm mm}}\\; \\times \\;{50}\\;{{\\rm mm}}\\; \\times \\;{10}\\;{{\\rm mm}}$50mm×50mm×10mm acrylic waveguide. When a blue laser beam excited a single spot on the screen, a disk-shaped cross-talk pattern appeared. Its intensity was 5 orders of magnitude lower than that of the excited spot. The solar cells attached to the waveguide edge harvested less than 0.8% of the incident optical power. The photons scattered by the phosphors are responsible for these characteristics, and the use of non-scattering luminescent materials is desired for improving them.