High power diode lasers with external feedback: Overview and prospects

Different external-cavity feedback techniques to improve the spatial beam quality and narrow the linewidth of the output beam from both BALs and TDLs are presented. Broad-area diode laser system with external cavity feedback around 800 nm can produce several Watts of output power with a good beam quality. Tapered diode laser systems with external-cavity feedback around 800 and 1060 nm can deliver more than 2 W output power with diffraction-limited beam quality and can be operated in single-longitudinal mode. These high-brightness, narrow linewidth, and tunable external-cavity diode lasers emerge as the next generation of compact lasers that have the potential of replacing conventional high power laser systems in many existing applications.