Schottky contact surface-plasmon detector integrated with an asymmetric metal stripe waveguide

A silicon-based Schottky contact photodetector integrated into a finite width asymmetric metal stripe supporting short-range surface plasmon polaritons is presented. Input optical energy is coupled into a bound mode supported by the stripe, leading to total absorption of in-coupled energy. The absorbed energy excites carriers in the metal stripe, some of which cross the Schottky barrier (internal photoemission) leading to a photocurrent under reverse bias. Significant enhancement in the quantum efficiency is observed for a thin metal stripe due to multiple internal reflections of excited carriers. The device holds promise for short-reach high-speed optical interconnects and silicon-based photonic circuitry.