Most physical laws hold true whether time is moving forward or backward ? that is, they are time symmetric. However, violation of time-reversal symmetry underlies many of today?s most important devices ? from nanoscale diodes of integrated electronics to the macroscale isolators and circulators of fiber optical networks. To enable next- generation applications like integrated nano- and micro-photonic circuits, it is crucial to manipulate time-reversal symmetry in optics. This project will investigate time and space symmetries in multi-length-scale photonic systems and explore the exciting applications and technologies that emerge when such symmetries are violated. Our multi-disciplinary team of scientists from five institutions will employ complementary strategies to violate time-reversal symmetry and induce non-reciprocal light transport in nano-, micro-, and macro-scale photonic systems. Our discoveries have the potential to enable a host of new technologies that will ultimately contribute to critical national needs in public health, information processing, computation, and communications. Team members will collaborate with visual and performing artists and develop educational modules for elementary and secondary school students. Each member will involve undergraduate and graduate students from their own and other institutions in their research through cutting-edge online workshops and courses. A key goal is to broaden outreach to underrepresented groups from high schools, community colleges, and minority- serving institutions and create new educational and community resources to advance STEM education.
In this EFRI NewLAW project, our multi-disciplinary team will employ a holistic approach to explore the emerging frontier of non-reciprocity and time-reversal symmetry breaking in photonic systems ranging from nanoscale plasmonic structures and dielectric micro- resonators to large scale integrated acousto-optic platforms. The research goals of the project will be achieved by synergistic efforts including theoretical investigation, numerical modeling, top-down and bottom-up materials synthesis, and device fabrication and characterization. Using complementary Hermitian and non-Hermitian approaches, the team aims to realize asymmetric and non-reciprocal optical transport in nanoscale, microscale, and macroscale systems. In Hermitian systems, acoustic and optical waves will be coupled in an integrated device in order to experimentally demonstrate how effective photon magnetic fields can influence photon transport. Utilizing the intrinsic phase properties of the acoustic wave, an effective gauge field can be generated for the optical waves, resulting in intriguing magnetic effects. This system will enable investigation of such fascinating effects as the optical analog of Lorentz forces and quantum Hall effect. Moreover, it will provide a new nonreciprocal platform based on a multi-physics, dynamically modulated system. Topologically protected photon edge state and one-way light transport will be demonstrated in large-scale photonic lattices. In non-Hermitian systems, judiciously positioned gain and loss will be investigated to develop technologies that can enable nano and microscale non-reciprocal components and circuits. In particular, the utilization of antilinear symmetries and exceptional points will provide new strategies to compensate or mitigate losses in many physical systems to enable unconventional devices, such as chiral lasers, circulators, unity-efficiency polarizers and on-chip chiral-symmetric optical power limiters. This project will build the theoretical and experimental foundation for new non-reciprocal photonic materials and devices of multiple length-scales, enabling next generation technologies to address critical national needs in information processing and communications.
