Tunable multilayer subwavelength metallic optical devices for polarization control and displacement sensing

University Of Florida, Gainesville FL

Investigators

Abstract

0621944 Dr. Ho Bun Chan, University of Florida Intellectual Merit: This project aims to construct and develop optical devices based on subwavelength metallic structures for polarization control and displacement sensing. Optical properties of multilayer subwavelength metallic structures, including slit arrays and hole arrays, will be explored. Adjacent metal layers are fabricated close to each other to allow the coupling of evanescent fields. Such structures possess optical properties that are not present in their single layer counterparts. For instance, the intensity of the transmitted light depends strongly on the lateral shift between the metal layers. One proposed device is a half wave plate whose operational wavelength range can be tailored by the device parameters instead of being limited by material properties. It also allows integration with other components due to its compact size and compatibility with planar fabrication. The strongly enhanced evanescent fields will also be exploited to improve the sensitivity of optical detection of displacement. The aim is to achieve sensitivities for in-plane motion that are comparable to interferometric detection for out of plane motion. The intellectual merit of the proposed research is determined by the novel utilization of the field enhancement and the near field coupling in multilayer metallic nanostructures for displacement sensing and polarization control. Understanding the coupling of evanescent fields in complex multi-layer metallic nanostructures is of fundamental interest and practical importance in designing photonic devices that could become important building blocks in future nano-optical systems. Broader Impacts: The proposed research holds promise in creating a new class of compact devices for polarization control that could enhance the performance of various optical subsystems. Transducers involving deformable subwavelength metallic nanostructures could lead to improvements in inertial sensing in navigation and guidance systems. Students participating in the proposed projects will gain invaluable experience in optical measurement and device fabrication. The program also includes participation of underrepresented groups.