Emission enhancements in phosphor chips with surface gratings

An oxide grating fabricated with standard microlithographic processes and patterned with interference lithography was fabricated on a solid LuAG:Ce3+ phosphor chip about 0.2 mm thick. Integrating sphere emission measurement shows an increase of 8.1% in the emission band from 520 to 550 nm, with the majority of the increase coming at steeper emission angles. This process may be a practical way to increase solid state lighting efficiency. This technique was effective even though the phosphor was not optically flat.