A simple, fast, and reliable characterization method for measuring junction temperature(Tj) on high power GaN-based light emitting diodes (LED) was presented in this study. Thermal characteristics of high power Light-emitting-diode have been analyzed by u A simple, fast, and reliable characterization method for measuring junction temperature(Tj) on high power GaN-based light emitting diodes (LED) was presented in this study. Thermal characteristics of high power Light-emitting-diode have been analyzed by u