Plasmonic pin-photodiode in InGaAsP layer stack

Plasmonic pin-photodiode in InGaAsP layer stack

In this article the photocurrent response of a novel ultra-small on-chip InP-based plasmonic pin-photodiode is analyzed at optical communication wavelength of 1.55 μm. When light propagates along a hybrid plasmonic InP-based waveguide, it couples to the plasmonic pin-photodiode and absorbs in the InGaAs absorption layer to generate photocurrent. The InP/InGaAsP pin-photodiode is optically simulated utilizing a three dimensional finite difference time domain (FDTD) method. The photo-response characteristics of InP-based photodiode, which depends on device structure parameters and biasing operation conditions, are discussed. Theoretical analysis for calculating 3 dB bandwidth as a function of device geometry is then presented. An internal quantum efficiency of 95% and a 3- dB bandwidth of over 70 GHz is determined for a 1.5 μm long and 1 μm wide device.