Plasmonic finite-thickness metal-semiconductor-metal waveguide as ultra-compact modulator

TL;DR

This paper introduces a plasmonic modulator based on a finite-thickness metal-semiconductor-metal waveguide, demonstrating its potential for ultra-compact, fast, and electrically controllable optoelectronic integrated circuits.

Contribution

It presents an analytical and numerical study of a novel F-MSM waveguide design with semiconductor gain, highlighting how thin metal layers improve device extinction ratio.

Findings

Higher extinction ratio achieved with thin metal layers

Electrical control of signal via semiconductor gain pumping

Analytical and numerical analysis of waveguide properties

Abstract

We propose a plasmonic modulator with semiconductor gain material for optoelectronic integrated circuits. We analyze properties of a finite-thickness metal-semiconductor-metal (F-MSM) waveguide to be utilized as an ultra-compact and fast plasmonic modulator. The InP-based semiconductor core allows electrical control of signal propagation. By pumping the core we can vary the gain level and thus the transmittance of the whole system. The study of the device was made using both analytical approaches for planar two-dimensional case as well as numerical simulations for finite-width waveguides. We analyze the eigenmodes of the F-MSM waveguide, propagation constant, confinement factor, Purcell factor, absorption coefficient, and extinction ratio of the structure. We show that using thin metal layers instead of thick ones we can obtain higher extinction ratio of the device.