Abstract

Within the last few years, solid state lighting (1) has attracted considerable interest because of its high potential for future lighting applications. White light is generated either by the mixing of red, green and blue LED light or by an up- conversion process involving blue/UV LEDs and phosphors. Nonetheless, in order to achieve high white light quality, for both processes a deeper understanding on the LED's emission characteristics is essential. Recently, a method using a commercial confocal microscope has been introduced in order to determine the emission properties of micrometer-sized LEDs based on InGaN/GaN technology (2). In this contribution we report on a confocal microscopy setup that provides a much larger measurement range for studying and characterization of millimetre sized high power LEDs.

© 2007 IEEE