Abstract
We present a new technique for measuring the temperature profiles of visible LED chips by use of a nematic liquid crystal with IR laser illumination. The LEDs studied have a multi-quantum-well structure. New features in this technique are the use of a high-power IR laser beam as the sensing light and the insertion of a color filter in the optical path to block the high-intensity LED light. For the LEDs measured, the conversion efficiency decreases by 70% when the junction temperature rises from 25 to 107 °C. This technique is a valuable tool for studying the performance of LEDs as a function of junction temperature.
© 2004 Optical Society of America
Full Article | PDF ArticleMore Like This
Yu-Ping Lan, Ru-Pin Pan, and Ci-Ling Pan
Opt. Lett. 29(5) 510-512 (2004)
A. d’Alessandro, R. Asquini, C. Gizzi, R. Caputo, C. Umeton, A. Veltri, and A. V. Sukhov
Opt. Lett. 29(12) 1405-1407 (2004)
Ming-Shan Tsai, I-Min Jiang, Chi-Yen Huang, and Chia-Chi Shih
Opt. Lett. 28(23) 2357-2359 (2003)