Digital optical network encryption with liquid-crystal grating metasurface perfect absorbers
Abstract
Green all-optical components represent a revolutionary toolbox for producing breakthrough applications that can rapidly change and control the properties of light, thus enabling the realization of innovative all-optical networks. Impactful, next-generation and eco-friendly data networks rely on diffractive optical components such as prisms and diffraction gratings. Although the technology is exciting, there are several limitations, such as lack of tunability and binary data exchange (diffraction gratings can efficiently switch light from one channel (transmission order) to another (diffraction order)). Metasurfaces are engineered surfaces with a thickness smaller than the wavelength of the incident light that allows the control of the optical wavefront over subwavelength thicknesses. A perfect absorber metasurface can be produced by suitably organizing subwavelength elements (e.g., plasmonic nanoparticles), resulting in an array of resonators that collectively act to achieve complete absorption of the resonant wavelength. However, perfect absorber metasurfaces lack tunability and fast response to external stimuli and do not allow data multiplexing and encryption. Light responsive liquid crystals (LCs) are an exciting class of photo-adaptive materials that a suitable light source can modulate in a brief time interval (ns or ps range). Photo-responsive LCs embedded in diffraction gratings have been extensively studied in the past years, thanks to a fruitful collaboration between the PI and AFRL. The combination of metasurface-based perfect absorbers and photo-responsive diffraction gratings represents a true breakthrough for realizing innovative and ultra-fast digital optical networks.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2023
- Source ID
- FA86552217007
Entities
People
- Luciano De Sio
Organizations
- Air Force Office of Scientific Research
- Sapienza University of Rome
- United States Air Force