GRAPHENE BASED OPTICAL MODULATOR USING FINITE DIFFERENCE TIME DOMAIN METHOD

Abstract

The thesis titled "Graphene Integrated Optical Modulator" investigates the performance and potential of graphene-based optical modulators in advancing optical communication systems. Utilizing the Finite-Difference Time-Domain (FDTD) method, this research models the interaction between light and graphene within an optical waveguide, focusing on key parameters such as applied voltage, electric field strength, and carrier mobility. The findings reveal that graphene based modulators exhibit high modulation efficiency across a broad range of frequencies, from visible to terahertz, due to graphene's unique properties, including high carrier mobility and ultra fast response times. The study demonstrates that optimal modulation efficiency is achieved at specific bias voltages and field strengths, underscoring the importance of precise parameter control. Additionally, the seamless integration of graphene with existing silicon photonics technologies enhances the functionality of current photonic devices without requiring substantial manufacturing changes. The research emphasizes graphene's suitability for low-power, high-speed optical modulation, applicable in high-speed data transmission and terahertz signal processing. A comprehensive literature review provides context by comparing traditional optical modulators and recent advancements in the field, highlighting graphene's potential to overcome the limitations of conventional materials. The methodology section details the simulation setup, including domain size, grid resolution, boundary conditions, and the initialization of field variables, offering insights into the simulation's accuracy and reliability. Results and discussions focus on the electric and magnetic field distributions, modulation efficiency, and the effects of various parameters. Comparisons with existing work highlight the improvements in modulation efficiency and potential for integration with silicon photonic technologies. The conclusion summarizes the key findings, emphasizing the high modulation efficiency and broadband capabilities of graphene-based modulators, and suggests future research directions, including optimizing fabrication techniques and exploring environmental effects on device stability. Overall, this thesis provides a detailed analysis of graphene-based optical modulators, demonstrating their potential to revolutionize optical communication systems with high-speed, energy-efficient, and versatile solutions.