Electro-Thermo-Optical Simulations of Phase-Change GST-SiC Plasmonic Optical Modulator for Telecom Applications

Abstract

This study proposes a novel plasmonic optical modulator integrating the phase-change material germanium-antimony-tellurium (GST) with a silicon carbide (SiC) waveguide for telecom applications. The design utilizes a 10 nm GST cladding layer and a 290 nm thick, 100 nm wide SiC ridge waveguide, with gold electrodes enabling electrothermal switching of GST between amorphous and crystalline states. Comprehensive simulations spanning optical, electrical-thermal, and opto-thermal domains investigated the modulator's performance. Optical simulations examine the effects of wavelength, ridge width, and GST thickness on effective refractive index, confinement factor, and effective area. Electrical-thermal simulations determines voltage pulse parameters for phase transitions and analyzed temperature distributions. Opto-thermal simulations explored temperature's influence on the effective refractive index during phase transitions. Results demonstrate the modulator's potential, achieving 160 Mb s⁻¹ at 1.55 µm. The SiC-GST integration offers high thermal conductivity, low thermo-optic coefficient, and significant refractive index contrast between GST phases, enabling efficient light modulation for high-performance, compact, energy-efficient optical modulators advancing integrated photonics.