Analysis of resonance enhancement in defect-mediated silicon micro-ring photodiodes operating at 1550 nm

The resonant defect-enhanced photodiode has received recent attention for its potential use in silicon photonic applications such as wavelength division multiplexing (WDM). Here, we analyze the nature of the resonant enhancement in micro-ring photodiodes by exploring the roles of defect content and ring geometry. Through the use of post-processing to gradually reduce the defect concentration, we demonstrate an optimized peak responsivity of 160 mA W super(-1) in a ring resonator having a linewidth of 0.12 plus or minus 0.01 nm and 12.8 plus or minus 0.9 dB extinction. We also show that the responsivity is insensitive to ring radius in the range between 10 mu m and 20 mu m, demonstrate the influence of a drop port waveguide on the resonant enhancement, and discuss design methodologies to enhance performance further.