Developing Isolators/Circulators for Quantum Photonic Integrated Circuits using Topological Photonic Crystals
Riley J. Barrett; other authors: Chandriker Kavir Dass, Piyush Shah, Michael Newburger, Said Elhamri, Robert G. Bedford
Isolators and circulators are critical components in both electric and photonic systems. In optical systems, their function is to allow light travelling in one direction to pass, but any reflected light from the opposite direction to be either blocked by an isolator or redirected by a circulator. However, these functions have yet to be applied to a quantum photonic integrated circuit (PIC) because isolators and circulators are either too bulky for an integrated circuit or not compatible with quantum components. Chiral photonics enabled by topological photonic crystals with hexagonal lattice of triangles present the building blocks to overcome these issues. Such structures are patterned and etched into thin (~170 nm) GaAs using nanolithography procedures, and then an underlying AlGaAs layer is undercut using HF, resulting in a suspended membrane of GaAs. It is important to ensure the process retains the required features to sustain the topological nature of the photonic crystal and understand how each nanofabrication step impacts the pattern fidelity. Scanning electron microscopy (SEM) allows us to evaluate the etching process and determine the area, depth, and triangularity of the triangles within the photonic crystal. We process SEM images to determine large-scale pattern fidelity and have developed a “triangularity” metric to evaluate the pattern fidelity. We have evaluated the efficacy of our measurement techniques which has shown promise and will lead to more accurate results. Over the course of the past nine months, we have been nearing the goal of at least 85% triangularity and we plan to begin integrating isolators/circulators into PIC platforms.
Primary Advisor's Department
Stander Symposium, College of Arts and Sciences
"Developing Isolators/Circulators for Quantum Photonic Integrated Circuits using Topological Photonic Crystals" (2023). Stander Symposium Projects. 3166.