Abstract: The invention is a semiconductor optical device and a method of manufacture. The device includes a first waveguide having an edge, and a second waveguide adjacent to at least a portion of the first waveguide including the edge so that light is coupled from the first to the second waveguide. The second waveguide has a modal index which is essentially constant at least at the edge of the first waveguide. The method includes forming at least the second waveguide by Selective Area Growth (SAG) using oxide pads of a particular geometry to achieve the essentially constant modal index. In one embodiment, the device is an expanded beam laser with an expander portion which is less than 300 microns.