Low-loss hydrogenated buried waveguide coupler integrated with a four-wavelength distributive Bragg reflector laser array on InP

An approach is proposed to realize the integration of a 4≫1 passive coupler with butt-jointed buried ridge structure distributive Bragg reflector lasers and transparent buried waveguides for Bragg section. The butt coupling facilitates an independent optimization of gain and Bragg sections and the proposed additional processing step, namely, localized hydrogenation of coupler regions, permits reducing dramatically the losses due to free holes in the p⁺-InP cladding layer. With a coupling efficiency of ∼90% and losses as low as ∼0.4 dB/mm, the integrated emitter with uncoated facets yielded output powers up to 0.4 mW for each wavelength at 100 mA. © 1997 American Institute of Physics.