By broadening the stripe width of the active waveguide region, it is possible to extract high optical powers from semiconductor broad area lasers. However, a weak output beam quality, optical filamentation, and high peak power densities will result, which are invoked by the amplification of higher order modes. We show an approach to influence the optical field inside the resonator by integrating optical phase structures directly into the waveguide. Those elements offer the possibility to enlarge the active gain area for the desired fundamental laser mode, while additional diffraction losses for higher order modes are generated, thus achieving an improved beam quality. We report on considerations in designing those elements and demonstrate a first experimental realization.
© 2013 Optical Society of America
Lasers and Laser Optics
Original Manuscript: July 26, 2013
Revised Manuscript: September 27, 2013
Manuscript Accepted: October 11, 2013
Published: October 31, 2013
Hans-Christoph Eckstein, Uwe D. Zeitner, Andreas Tünnermann, Wolfgang Schmid, Uwe Strauss, and Christian Lauer, "Mode shaping in semiconductor broad area lasers by monolithically integrated phase structures," Opt. Lett. 38, 4480-4482 (2013)