Collaborative Research: Harnessing Non-Hermitian Topology for Ultrafast Laser Modulation and Quantum Entanglement Generation

Nontechnical description: Modern information technologies and infrastructures increasingly depend on fast, energy-efficient optical communication and emerging quantum technologies to support artificial intelligence, cloud computing, secure communications, and advanced sensing. This project will investigate a new class of photonic systems based on non-Hermitian point-gap topology, an emerging area of physics that enables new ways of controlling how light propagates and concentrates in arrays of semiconductor lasers and optical parametric oscillators. By exploiting these topological effects, the project seeks to develop compact photonic devices that operate more robustly, transmit data at higher speeds with lower energy consumption, and generate customizable quantum states of light. The research combines complementary expertise at Auburn University and the City University of New York to advance both fundamental science and integrated photonic technology. Expected outcomes include new design principles for high-speed semiconductor lasers and scalable quantum light sources that could benefit optical communications, quantum sensing, quantum information processing, and future computing technologies. This interdisciplinary project will provide valuable research opportunities for graduate, undergraduate, and advanced high school students in photonics, semiconductor devices, quantum information, and applied physics. Additional activities include outreach to K–12 students through hands-on demonstrations and public lectures, development of open educational resources and computational tools, and incorporation of research discoveries into undergraduate and graduate courses. Together, these activities will broaden participation in STEM, strengthen the future workforce, and advance the nation's scientific and technological capabilities. Technical Description: This collaborative project investigates the dynamical and quantum properties of non-Hermitian point-gap photonic systems based on semiconductor laser arrays and optical parametric oscillator (OPO) arrays with engineered non-Hermitian gauge fields. The project integrates analytical theory, numerical modeling, inverse device design, semiconductor nanofabrication, and experimental characterization to establish fundamental understanding of collective spatiotemporal dynamics, modulation response, linewidth, relative intensity noise, and quantum correlations in non-Hermitian photonic systems. The research consists of three interconnected thrusts. The first thrust develops theoretical frameworks for dynamical stability, phase synchronization, transient response, modulation bandwidth enhancement, and quantum noise in non-Hermitian gauged laser arrays. The second thrust designs, fabricates, and experimentally demonstrates electrically injected non-Hermitian ring laser arrays to investigate topological light funneling, coherent single-mode operation, linewidth, relative intensity noise, and ultrafast direct modulation. The third thrust extends these concepts to coupled OPO arrays, establishing theoretical and experimental approaches for engineering squeezing spectra and broadband quantum entanglement through non-Hermitian topology, synthetic gauge fields, and tailored coupling architectures. The project will establish foundational understanding of how non-Hermitian topology governs the dynamical and quantum behavior of nonlinear photonic systems while demonstrating new approaches for high-speed optical transmitters and integrated quantum light sources. The resulting design principles are expected to enable robust coherent power combining, substantially enhanced direct modulation bandwidth, and tailorable generation of squeezed and entangled optical states for future communication, sensing, and quantum technologies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.