Photon detection and emission of epitaxial Ge on Si with potential applications in microwave photonic filters

Microwave photonic filter requires high-speed Radio frequency(RF)-optical and optical-RF signal conversion. Light sources and photo-detectors(PDs) are indispensible for such conversions. Monolithic integration of functions of photon emission and detection is demonstrated using epitaxial Ge on Si. The fabricated waveguided PD shows a high bandwidth of10 GHz with the responsivity of0.8 A/W and dark current of150 nA at-1V. The photoluminescence(PL) properties of P-implanted Ge are studied, and an improved annealing process is demonstrated to enhance the light emission by1 order. Electroluminescence(EL) is obtained from the waveguided n+-Ge light-emitting diode(LED), and the emitted power has been studied as a function of injected current. The successful demonstration of both waveguided PD and LED on single Si chip would be attractive for fabricating a compact size microwave photonic filter with low cost and high integrity.?2011 IEEE