High-power and high-efficiency 915 nm broad-area laser diodes with window structure

摘要

High power broad-area laser diodes in a 9xx-nm spectral range have been widely employed in industrial applications including direct material processing, and pumping fiber lasers and solid state lasers [1]. Those applications require high output power and high efficiency for the employed devices in the systems. However, the available output power is limited by catastrophic optical mirror damage (COMD) [2], which is caused by the facet heating due to optical absorption. One of the most promising approaches to solving the COMD problem is introduction of a window (a transparent region to laser light) by quantum well intermixing (QWI) and reduce optical absorption at the facet. QWI can be achieved by the various methods, such as impurity induced disordering, ion irradiation induced intermixing, and impurity-free vacancy disordering (IFVD) [3,4]. Among them, IFVD is considered to be the most promising technique because it retains high crystal quality and low optical propagation losses. However, it is difficult to perform stable IFVD process due to poor controllability and reproducibility. In this paper, we present high-power high-efficiency 915 nm broad-area laser diodes with the window structure fabricated using optimized IFVD process.