Infrared upconversion imaging in nonlinear metasurfaces

Abstract

Infrared imaging is a crucial technique in a multitude of applications, including night vision, autonomous vehicle navigation, optical tomography, and food quality control. Conventional infrared imaging technologies, however, require the use of materials such as narrow bandgap semiconductors, which are sensitive to thermal noise and often require cryogenic cooling. We demonstrate a compact all-optical alternative to perform infrared imaging in a metasurface composed of GaAs semiconductor nanoantennas, using a nonlinear wave-mixing process. We experimentally show the upconversion of short-wave infrared wavelengths via the coherent parametric process of sum-frequency generation. In this process, an infrared image of a target is mixed inside the metasurface with a strong pump beam, translating the image from the infrared to the visible in a nanoscale ultrathin imaging device. Our results open up new opportunities for the development of compact infrared imaging devices with applications in infrared vision and life sciences.

High Quality Factor Silicon Membrane Metasurface for Intensity-Based Refractive Index Sensing

“…In Figure 2a, the NC radius and height are 250 and 563 nm. The geometrical parameters of the metasurface, and consequently the BIC wavelength, were chosen by performing a parametric sweep in the range of dimensions accessible with well-established fabrication techniques for the most common dielectric materials [25,26]. The eigenmode wavelength can be arbitrarily tuned by changing the height of the cylinder.…”

Applications of Hybrid Metal‐Dielectric Nanostructures: State of the Art

“…Nonlinear frequency generation processes have recently demonstrated their utility in many different applications. In particular, they are used in laser systems to enlarge the range of accessible frequencies and have been proposed for nonlinear imaging [ 299 ] and even for biological uses, like in visualization of biological molecules [ 300,301 ] and inner cell processes. [ 302,303 ] Hybrid metal‐dielectric nanostructures have been introduced as efficient geometries to enhance SHG and THG.…”

Nonlinear Dielectric Nanoantennas and Metasurfaces: Frequency Conversion and Wavefront Control

“…The ideal starting point for nonlinear phase control at constant amplitude is a meta-atom emitting in a defined direction (e.g., along the vertical axis) with the desired phase at maximum nonlinear conversion efficiency. By encoding the adequate phase pattern into a packed array of such meta-atoms, control of the directionality of the SHG or THG emission, 8,32,121,178 as well as nonlinear imaging, 33,176 vortex generation, 32 and holography, 7,8,178 have been proven experimentally. Gigli et al 121 investigated a (100)-AlGaAs "nanochair" meta-atom to build nonlinear metasurfaces for beam steering and subwavelength focusing of the SH radiation.…”