By-Emitter Analysis of 450-Nm Emitting High-Power Diode Laser Bars

We present an analysis of optical and thermal properties of GaN-based blue-emitting high-power diode laser arrays (bars). Parameters such as emission power and temperature are monitored for each single emitter of arrays consisting of 23 emitters. The obtained data are compared with modeling of the electro-optic properties. In contrast to the well-known infrared bars, the thermal properties in the blue-emitting bars control the individual emitter properties to a very high degree and lead to considerable variations in emitter power, in extreme cases up to 50%. Such extreme cases occur, for example, when emitters fail and thus act as a heat source for their surroundings. Nevertheless these bars reach record output powers and are on the way to becoming major sources of photonic power in the blue spectral range.