Abstract Title: Novel Photonic Structures for Lasers and Sensing by Using Gain and Loss
The proposed research aims to introduce a new paradigm in optics by utilizing the unconventional properties of exceptional points arising in systems with gain and loss. These features can be employed to build structures with customized properties and functionalities- previously thought to be unattainable. The applications of such developments range from on-chip communication systems, to high power semiconductor lasers, to sensing. This research will result in a better understanding of how amplification and attenuation can be independently manipulated and harnessed in both optically and electrically pumped arrangement and will shed light on the role and the fundamentals of exceptional points in optics. In addition, the proposed work provides a bridge between mathematics, quantum physics, and engineering while promoting the concept of exceptional points in optics. These ideas could lead to new design tools that can be deployed to address some of the long-standing problems in laser physics. If successful, this effort could potentially transform chip-scale integrated photonics and high power semiconductor laser technologies. Due to the interdisciplinary nature of the proposed activity, the students engaged in this project will have the opportunity to prepare for a broad range of future careers by experiencing all the steps involved in a scientific endeavor, starting from conceiving an idea that perhaps originates from mathematics, to experimentally demonstrating the anticipated behavior, and finally building a prototype device. By means of presentations, publications, and classroom/laboratory teaching, the knowledge acquired during the course of this project will be disseminated to a broader audience. This program will provide research opportunities not only to graduate, but also to undergraduate, and K-12 students. Finally, students from minority and under-represented groups will be proactively integrated into the research environment.
Non-Technical Description: The proposed effort will make use of the physics and peculiarities of non-Hermitian exceptional points (EPs) in order to develop alternative strategies in designing novel photonic devices that complement and/or improve existing integrated photonic circuits. In a photonic system, exceptional points can be advantageously introduced through a judicious interplay between refractive index shaping and gain-loss contrast. Along these lines, two endeavors associated with chip-scale photonic components and networks will be pursued: (i) demonstrating a new class of single mode integrated lasers with increased brightness and/or spectral purity, (ii) enhancing the sensing characteristics of active photonic molecules by exploiting the inherent features of higher-order exceptional points. The prospect of using InP technologies as a versatile platform to explore the physics and applications of exceptional points in optics will also be investigated.