A semiconductor laser that includes an active region, claddings and electrical contacts to stimulate emissions from the active region, where a coupled waveguide guides emission. The waveguide includes a broad area straight coupling region that fans out into an array of narrower Individual curved coupled waveguides at an output facet of the laser. The individual curved coupled waveguides are curved according to Lorentzian functions that define the waveguide curvature as a function of position along the device.

The integral length of each individual curved coupled waveguide differs from adjacent individual curved coupled waveguides by an odd number of half-wavelengths. The coupled waveguide array shapes the optical field output of the semiconductor laser such that a large fraction of the power is emitted into a small angular distribution using interference phenomena. A laser of the invention produces high power output with a very high quality, narrow beam shape.