Room Temperature O-band DFB Laser Array Directly Grown on (001) Silicon

Several approaches for growing III-V lasers on silicon were recently demonstrated. Most are not compatible with further integration, however, and rely on thick buffer layers and require special substrates. Recently, we demonstrated a novel approach for growing high quality InP without buffer on standard 001-silicon substrates using a selective growth process compatible with integration. Here we show high quality InGaAs layers can be grown on these InP-templates. High-resolution TEM analysis shows these layers are free of optically active defects. Contrary to InP, the InGaAs material exhibits strong photoluminescence for wavelengths relevant for integration with silicon photonics integrated circuits. Distributed feedback lasers were defined by etching a first order grating in the top surface of the device. Clear laser operation at a single wavelength with strong suppression of side modes was demonstrated. Compared to the previously demonstrated InP lasers 65% threshold reduction is observed. Demonstration of laser arrays with linearly increasing wavelength prove the control of the process and the high quality of the material. This is an important result toward realizing fully integrated photonic ICs on silicon substrates.