Phys.org October 16, 2024 Nonlinear metasurfaces are used for infrared imaging and spectroscopy. However, due to their low conversion efficiencies several strategies have been adopted to enhance their performances. Using resonances at signal or nonlinear emission wavelengths results in a narrow operational band of the nonlinear metasurfaces, which has bottlenecked many applications, including nonlinear holography, image encoding, and nonlinear metalenses. An international team of researchers (UK, Australia) introduced a new nonlinear imaging platform to overcome this issue. They demonstrated broadband nonlinear imaging for arbitrary objects using metasurfaces. A silicon disk-on-slab metasurface was introduced with an excitable guided-mode resonance at the […]
Tag Archives: Infrared imaging
Let there be light! New tech allows people to see in the dark
Nanowerk June 10, 2021 Conventional infrared imaging technologies require the use of materials such as narrow bandgap semiconductors, which are sensitive to thermal noise and often require cryogenic cooling. An international team of researchers (Australia, Italy, UK, Germany, France, Bulgaria) developed and demonstrated a proof-of-concept compact all-optical device to perform infrared imaging in a metasurface composed of GaAs semiconductor nanoantennas using a nonlinear wave-mixing process. Experimentally they showed 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 […]
Thin, large-area device converts infrared light into images
EurekAlert May 5, 2021 An international team of researchers (USA – UC San Diego, University of Southern Mississippi, South Korea) has developed an organic upconversion imager that is efficient in both optical and electronic readouts, extending the capability of human and machine vision to 1400 nm. The imager structure incorporates interfacial layers to suppress non‐radiative recombination and provide enhanced optical upconversion efficiency and electronic detectivity. The photo response is comparable to state‐of‐the‐art organic infrared photodiodes exhibiting a high external quantum efficiency of ≤35% at a low bias of ≤3 V and 3 dB bandwidth of 10 kHz. With a large […]