Showing Spotlights 1 - 8 of 23 in category Metamaterials, Metasurfaces (newest first):
A new generation of lenses - metalenses - is starting to replace bulky curved lenses with simple, flat surfaces that use nanostructures to focus light. These flat surfaces - meatsurfaces - have enabled the design of diffraction-based flat devices to replicate the functionalities of conventional lenses with sub-wavelength or few-wavelength thicknesses. Researchers have now successfully designed and experimentally demonstrated an inverse-designed metalens to operate at a near-infrared wavelength.
Apr 8th, 2021
Inspired by chiral molecular structures, scientists are developing strategies to build artificial chiral materials by mimicking natural molecular structures using functional materials. Specifically, metal nanomaterials exhibit tailorable optical properties upon excitation of surface plasmons and become one of the most promising components to realize chiral optical metamaterials. Researchers now demonstrate all-solid-phase reconfigurable chiral nanostructures, where the geometry and chiroptical properties can be dynamically tailored and fully controlled on a solid substrate without liquid media.
Feb 1st, 2021
Researchers have developed a high-throughput, scalable nanocomposite printing method to manufacture metalenses at low cost, paving the way to commercializing them. The nanocomposite material, which is also suitable for high-efficiency metasurfaces, can be molded into metalenses just by one step of printing without any secondary operations such as thin-film deposition or plasma etching. The researchers synthesized their nanocomposite by dispersing silicon nanoparticles in the matrix of UV-curable resin to achieve a high-refractive index to increase the efficiency of the metalenses. The printing mold is reusable, so the large-scale metalenses can be printed rapidly and repeatedly.
Jan 12th, 2021
A major challenge for nanophotonics engineers is the wide range of optical responses that metamaterials and other nanoplasmonic structures can generate. In the past few years, machine learning has emerged as a powerful tool for sifting through this vast universe of possible design parameters to aid the design of nanophotonic devices tailored for specific applications. A novel approach uses a type of neural network called a mixture density network to solve the non-uniqueness problem of machine learning algorithms, while also improving accuracy.
Sep 17th, 2020
Researchers have designed and fabricated an ultrasensitive plasmonic biosensor with the integration of atomically thin perovskite nanomaterials on metasurfaces. For that purpose, they used an atomically thin perovskite nanomaterial with high absorption rate, sandwiched between hexagonal boron nitride and graphene layers, which enables the precise tuning of the depth of the plasmonic resonance dip. This biosensor can reach an ultra-high plasmonic sensitivity for detecting small-molecule, low-concentration analytes.
Jul 10th, 2020
Researchers have identified kirigami as an intriguing tool to create programmable mechanical metamaterials with unconventional mechanical and morphological responses. These reconfigurable metamaterials offer a new material platform to achieve dramatic changes of mechanical and optical properties, which are arising from dynamically tunable geometrical structures. A key feature of kirigami metamaterials is that they are conveniently cut when flat and then exploit local elastic instabilities to transform into complex 3D configurations upon stretching.
Dec 12th, 2019
Terahertz (THz) frequencies, which occupy a middle ground between microwaves and infrared light, are seen as the future of wireless communications because they offer a higher bandwidth capacity for data transmission than currently used microwave radiation. Researchers have improved the photoconductive switch, a key optoelectronic element in THz technology, with a perfectly-absorbing photoconductive metasurface. The perfect absorption within this metasurface allows to make the active region of THz wave detectors significantly thinner in comparison to conventional detectors. Apart from reducing the size of THz detectors, it also improves their efficiency.
Apr 24th, 2019
Inspired by chiral molecular structures, scientists are developing strategies to build artificial chiral materials by mimicking natural molecular structures using functional materials. Specifically, metal nanomaterials exhibit tailorable optical properties upon excitation of surface plasmons and become one of the most promising components to realize chiral optical metamaterials. New work provides a macroscopic model to understand the origin of chirality because the structures of the chiral meta-molecules are observable under a microscope and also the optical chirality is several orders of magnitude stronger than the intrinsic chirality of organic molecules.
Mar 14th, 2019