Realization of Compact High-Performance EAM Based on Numerical Analysis of ITO, VO₂ and Graphene on SiO₂ Platform

Plasmonic based electro-absorption modulators (EAMs) has paved the way for high-speed photonic integrated circuits (PICs). This paper demonstrates the numerical analysis and the structural design of the EAM using various plasmonic materials, such as vanadium dioxide (VO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>), indium-tin-oxide (ITO) and graphene, to modulate signals traveling through the waveguide on an SiO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> platform. It also explores key performance metrics, including the extinction ratio (ER) and the figure-of-merit (FOM), which is related to the device's insertion loss (IL). By optimizing the structural parameters and utilizing the plasmonic materials, the device characteristics, especially the effective-mode-index (EMI), is modified to attain the epsilon-near-zero (ENZ) condition. The ITO-based EAM attains a high ER of 22.24 dB/μm with a FOM of 482.45, while the graphene-ITO based EAM obtains an ER of 20.31 dB/μm and a FOM of 296.06 at 1.55 μm wavelength. Both devices have an energy consumption per bit (E<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">bit</sub>) below 2.20 fJ/bit and modulation frequency (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$f$</tex-math></inline-formula>) exceeding 1300 GHz at an IL <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&lt; $</tex-math></inline-formula> 0.07 dB/μm. The investigated EAMs hold potential for future-generation PICs.