Physically Robust Metasurfaces for High Power Optoelectronics Applications
Abstract
Optoelectronic sources and detectors that operate at high power levels are a highly relevant class of technologies to naval warfighter missions. These technologies cover wavelength ranges spanning the ultra-violet to infrared frequencies, and they are used in a broad range of applications in the sky and on the ground. Metamaterials, which are photonic devices based on the subwavelength-scale structuring of dielectric and metallic media, are a natural candidate technology for augmenting the capabilities of high-power optoelectronic systems. However, the traditional form of metamaterials, which are patterned thin films of nanostructures, do not work for high power device applications, and new concepts in which materials are structured in physically robust ways need to be developed to advance these technologies.Our research goal is to develop new physically robust schemes that can improve the antireflection characteristics and wavefront engineered response of material interfaces in high power optoelectronic devices. We will focus on two material schemes that will enable the structuring of these interfaces in a manner that is tolerant to high optical power exposures. The first is the direct etching of structures into single crystal optoelectronic materials to produce surface relief patterns. This scheme is physically robust because the final devices are monolithic and monocrystalline, and they contain no heterogeneous material interfaces. The second is the fabrication of scalar diffractive optical multi-layer metamaterials, which have feature sizes an order of magnitude larger than conventional metamaterials and possess superior bonding and adhesion properties between different materials. This research will be performed in collaboration with Drs. Lynda Busse and Brandon Shaw of the Naval Research Laboratory, who are experts in the processing of optoelectronic materials and their integration into naval-specific electromagnetic systems.The heart of the proposed research is the development of data-driven inverse design methods, based on optimization and machine learning, to design these structures. The proposed ideas build on concepts initiated by PI Fan over for the last five years, where his group has researched state-of-the-art metasurface design using adjoint-based topology optimization and generative machine learning models. Much of this research was initiated by a prior project with the ONR (N00014-16-1-2630), which catalyzed many breakthroughs in inverse design, including: the first demonstrations of robust, topology-optimized diffractive optical elements, an analysis on how freeform devices operate, the extension of topology optimization to aperiodic metasurfaces,and the used of generative neural networks for global metamaterial optimization.If successful, our design platform will not only improve the capabilities of high power optoelectronics applications, it will serve as a broadly useful and usable platform for many metamaterial applications. The reason is because our proposed schemes of surface relief structuring and scalar diffractive optics are readily compatible with conventional material patterning and structuring methods. Surface relief structuring can be performed economically and over large areas using imprint lithography, which is becoming a commercial standard for large area photonic technologies. Scalar diffractive optical devices have features that are microscale, meaning they can be made cheaply and quickly using gray scale optical lithography. We envision that the results from this research will prompt new technological solutions for anti-reflection coatings, filters, and lenses, as applied to macroscopic crystalline and wafer-based devices.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 17, 2020
- Source ID
- N000142012105
Entities
People
- Jonathan A. Fan
Organizations
- Office of Naval Research
- Stanford University
- United States Navy