Slab-coupled optical waveguide lasers: a review

ABSTRACT This paper is a review of the recently introduced slab-coupled-optical-waveguide laser, a high-power, high-brightness semiconductor laser source that emits light in a single-spatial, lowest-order mode that is nearly circular in cross section and has a modal diameter of several micrometers. Such lasers have been demonstrated in InGaAs-InP materials, emitting near 1.3- µm wavelength, and in AlGaAs-InGaAs-GaAs materials, emitting at several wavelengths in the range between 915 and 980 nm. CW output power over 1 W has been obtained in diffraction limited beams with over 80% coupling efficiency to single-mode optical fibers. This coupling is achieved by simple butt coupling of the fiber directly to the laser without the use of optical lenses. Keywords: High-power diode lasers, semiconductor lasers, single-mode semiconductor lasers 1. INTRODUCTION Slab-coupled-optical-waveguide lasers 1-3 (SCOWL devices) are the most recently developed example of a growing number of semiconductor laser structures that produce high optical power with good beam quality. Several types of devices now have been demonstrated that provide CW power levels in the 1-W class with single-spatial-mode, diffraction-limited, or nearly diffraction-limited, beams. These include phased-locked arrays of anti-guided diode lasers