Comparison of electro-optical, spectral, and spatial beam parameters of 785nm DBR tapered lasers with different grating lengths
4 mm long DBR tapered diode lasers at 785 nm with three different lateral layouts will be presented. The devices consist of an unpumped DBR section, a ridge waveguide section, and a tapered section with a full taper angle of 6°. The impact of different lengths of the 10th order surface DBR gratings on the spectral behavior and the beam parameters at different RW currents will presented. With the best layout, the devices reach up to 7 W of optical output power together with a narrow spectral width smaller than 19 pm and a beam parameter M2 below 3 (1/e2 level).
Bernd Sumpf received the diploma in Physics in 1981 and the Ph.D. degree in 1987 from the Humboldt-Universität Berlin for his work on lead salt diode lasers for spectroscopic applications. From 1993 till 1997 he worked at the Technische Universität Berlin on high-resolution spectroscopy and difference-frequency generation. In 1997 he received the postdoctoral lecture qualification. Since 2000 he works at the Ferdinand-Braun-Institut, Leibniz Institut für Höchstfrequenztechnik, Berlin, Germany on high power and high brightness diode lasers and diode lasers and their application for Raman spectroscopy in life sciences. He is author of more than 330 publications and inventor and co-inventor of 5 patents in the field of diode lasers and laser spectroscopy.