Plasmonic modulator based on gain-assisted metal–semiconductor–metal waveguide

Abstract

We investigate plasmonic modulators with a gain material to be implemented as ultra-compact and ultra-fast active nanodevices in photonic integrated circuits. We analyze metal-semiconductor-metal (MSM) waveguides with InGaAsP-based active material layers as ultra-compact plasmonic modulators. The modulation is achieved by changing the gain of the core that results in different transmittance through the waveguides. A MSM waveguide enables high field localization and therefore high modulation speed. Bulk semiconductor, quantum wells and quantum dots, arranged in either horizontal or vertical layout, are considered as the core of the MSM waveguide. Dependences on the waveguide core size and gain values of various active materials are studied. The designs consider also practical aspects like n-and p-doped layers and barriers in order to obtain results as close to reality. The effective propagation constants in the MSM waveguides are calculated numerically. Their changes in the switching process are considered as a figure of merit. We show that a MSM waveguide with electrical current control of the gain incorporates compactness and deep modulation along with a reasonable level of transmittance.

Plasmonic modulator optimized by patterning of active layer and tuning permittivity

“…Depending on a mode, either an index modulator (with Δn > 20%) or absorption modulator can be utilized [15]. An absorption modulator based on a metalsemiconductor-metal structure with the gain core is proposed and analyzed in [16]. InP-based semiconductor materials allow achieving high gain and even a complete loss compensation in the structure.…”

Nanophotonic Modulator with Bismuth Ferrite as Low-loss Switchable Material

“…In this case a BFO-based plasmonic modulator can have FoM up to 67, which is much higher than in previously reported devices based on indium tin oxide, vanadium dioxide, or InGaAsP active layers [2,6,12,13].…”

Wave-Guiding Analysis of Annular Core Geometry Metal-Clad Semiconductor Nano-Lasers

“…Here use has been made of peak material gains in the range 2000cm −1 to 6000cm −1 [24], [30] and a diffusion length of 400 nm. Fig.…”

“…It is straightforward to examine alternative configurations and notably the use of alternative surrounding media. Following earlier work the core semiconductor material is assumed to be In 0.53 Ga 0.47 As with a refractive index of 3.53 at the operating wavelength λ o = 1.55μm [24]. The metal cladding is taken to be gold with a refractive index of 0.52 -j10.74 [25] and the thickness of metal-clad is assumed to be 20 nm [18].…”