Defect mediated detection of wavelengths around 1550 nm in a ring resonant structure

In this paper we outline recent results which combine defect mediated Photo-Detectors (PDs) in a Ring Resonator (RR) structure. By exploiting the multiple-pass of the optical signal through the detector, we are able to significantly decrease the size of the detector structure while maintaining good responsivity (typically 0.1 A/W). In such a geometry the detector bandwidth is not capacitance limited, while the leakage current is reduced toward 1 nA. We also show that these PDs may be used in the drop port of a RR to monitor the propagating signal. These devices have applicability in multiplexing and potential for integration with high speed modulation functionality.