Cavity-enhanced photocurrent generation by 1.55 μm wavelengths linear absorption in a p-i-n diode embedded silicon microring resonator

We demonstrate 20-fold cavity-enhanced photocurrent generation in $1.55\mu \text{m}$ wavelengths in a p-i-n diode embedded silicon microring resonator with $Q$ factor of 8000. The on-resonance wavelength shows linear responsivity of 0.12 mA/W upon 0 V bias and 0.25 mA/W upon −15 V bias. We attribute the linear absorption to surface-state absorption at the microring waveguide interfaces. Our experiments indicate that the photocurrent generation is linear to the estimated coupled power up to $\sim 500\mu \text{W}$ .