A metal layer formed on the backside of InGaN∕sapphire-based light-emitting diodes deteriorates the inherent optical power output. An experimental approach of a suspended die is employed to study the effects of such metal layers via a direct comparison in radiant flux from a discrete die with and without a reflector. A sphere package that employs no reflector is proposed and fabricated. Light extraction of the sphere design is discussed; a light source in the sphere package would not have to be either an ideal point or placed at the center of the sphere, due to a finite critical angle at the sphere∕air interface.
© 2007 Optical Society of America
Original Manuscript: April 10, 2007
Manuscript Accepted: May 30, 2007
Published: August 9, 2007
Hisashi Masui, Natalie N. Fellows, Hitoshi Sato, Hirokuni Asamizu, Shuji Nakamura, and Steven P. DenBaars, "Direct evaluation of reflector effects on radiant flux from InGaN-based light-emitting diodes," Appl. Opt. 46, 5974-5978 (2007)