Research Projects

Optical circulators are critical components in advanced photonic systems, routing light unidirectionally between multiple ports, which is essential for applications such as bidirectional optical communications, wavelength-division multiplexing, and signal isolation. Traditional optical circulators are bulky, fiber-based components that are difficult to integrate into the compact and scalable photonic circuits needed for modern technologies. This project aims to address these challenges by designing and demonstrating a high-performance optical circulator that is fully compatible with CMOS (complementary metal-oxide-semiconductor) fabrication processes, enabling large-scale production and integration into silicon photonic circuits. Research Plan: 1. Design and Conceptualization: In this phase, the focus will be on exploring existing designs for high-speed modulators and their application in optical circulators. The challenge lies in achieving non-reciprocal light propagation—essential for an optical circulator—through modulation techniques. Electro-optic modulators, known for their speed and CMOS compatibility, will be examined to understand how they can be utilized to direct light in a unidirectional manner across multiple ports. 2. Simulation and Optimization: The second phase will involve simulating the proposed designs using advanced computational tools like Lumerical FDTD (finite-difference time-domain). The simulations will focus on optimizing the performance of the circulator by studying the interaction between the light, modulators, and waveguide structures. Critical performance metrics—such as isolation ratio, bandwidth, and footprint—will be evaluated during this phase, ensuring that the design meets the necessary criteria for practical implementation. 3. Fabrication and Testing: In the final phase, the optimized design will be fabricated. The fabrication process will integrate high-speed modulators with the circulator structure, ensuring that the device can be mass-produced using industry-standard processes. After fabrication, the device will undergo thorough testing and characterization to evaluate its performance in real-world conditions. Key performance indicators such as isolation ratio, insertion loss, bandwidth, and power consumption will be measured and compared to the simulation results. Innovation and Impact: This project introduces a novel approach to optical circulator design by leveraging high-speed modulation techniques, rather than relying on traditional magneto-optic or non-linear effects. This shift not only offers a more practical, CMOS-compatible solution but also allows for higher bandwidth and lower power consumption. High-speed electro-optic, combined with compact waveguide geometries, have the potential to enable a fully integrated circulator that can operate efficiently in photonic systems, overcoming the limitations of bulkier, fiber-based devices.