| Comlase's reactor for performing its Nitrel process (top). Image: Comlase. The ultra-high vacuum chamber features a nitrogen ion gun and several electron guns. A stream of nitrogen ions are used to mill the facet of a laser diode and create a smooth, flat surface that is free from any impurities or roughness. The ions then form a thin nitride (GaN, InN or AlN) layer that seals the surface, giving a chemically stable, durable base that acts a barrier to oxygen and moisture. Optical thin-film coatings are then deposited on top. Lifetime data for Nitrel (Fig. 1) and untreated (Fig. 2) AlInGaAs 805 nm multimode laser diodes driven at 60-80 W power levels and a junction temperature of 90 °C. |
