InGaAsP closely spaced dual wavelength laser

Abstract

The fabrication and performance characteristics of an independently controllable closely spaced dual wavelength laser structure are described. The laser structure utilizes semi-insulating (Fe-doped InP) layers both for confinement of the current to the active regions and for separation of the active regions of the two lasers. Both lasers emit in single frequencies near 1.55 μm by virtue of frequency selective feedback provided by a second order grating. The light coupled into a single mode fiber from both lasers is about 5 dB smaller than that for optimum coupling arrangement of each laser. Dual wavelength laser structures of this type are useful for wavelength multiplexed optical transmission systems.