Showing Spotlights 17 - 24 of 127 in category Nano-optics, -Photonics (newest first):
Researchers report an interesting phenomenon of two-dimensional (2D) hexagonal boron nitride (h-BN)-induced planar-alignment of a nematic liquid crystal and the subsequent optical and electro-optical effects. Liquid crystals (LCs) are optically anisotropic materials, and they are widely used in electro-optical display technology, known as liquid crystal displays (LCDs). Understanding the alignment phenomena of a nematic LC on a surface remains an important area of research, as the alignment process determines the LC's molecular orientation and conformation - which influence the LC's optical and electro-optical characteristics in LCDs.
Jan 9th, 2019
Motivated by the outstanding performance of graphene, graphene-like 2D materials have been intensively investigated, such as topological insulators, transition metal dichalcogenides (TMDs) and black phosphorous. Recently, 2D titanium disulfide, a typical TMD, is found to have strong light absorption properties from visible to infrared region, which is highly attractive for applications in nonlinear photonics. Researchers have fabricated a novel saturable absorber device is successfully fabricated based on 2D TiS2 nanosheets for ultrashort pulse generation and all-optical thresholding at the communication band.
Dec 27th, 2018
Over the past several years, metal nanoparticles photosensitization over semiconductors with a large band gap has emerged as a promising strategy for developing visible-light responsive photocatalytic materials. In new work, researchers demonstrate a new plasmonic metamaterial can absorb nearly 100% of incident light (of a specific color) and use this energy to accelerate the production of chemicals. In constructing the near-perfect absorber, the researchers employ gold nanoparticles, TiO2 as the spacer layer, and a continuous gold thin film as the rear reflective layer.
Nov 28th, 2018
Researchers have developed a new type of optical manipulation method to achieve versatile manipulation of objects with different sizes and types using optical heating. In this new technique, nanoparticles get trapped at temperature hot spots instead of electrical hot spots, which demonstrates a different working mechanism and approach from the traditional optical manipulation techniques. Due to this unique working principle, stable trapping of large metallic nanoparticles and miniscule quantum dots on single nanoantennas with extremely low optical power is achieved.
Oct 3rd, 2018
Recently developed concepts in photonic designs and meta- and nanomaterials have improved the effectiveness of passive radiative coolers that function in the daytime. Whereas all of these radiative coolers are white or silver in color, researchers have now presented concepts and strategies for daytime radiative cooling systems that offer aesthetically desirable colors and patterns. These device not only emit infrared waves effectively under a clear sky, but also displays vivid colors.
Sep 6th, 2018
Researchers have developed an all-optical lithographic technique called 'optothermoplasmonic nanolithography' (OTNL) to achieve high-throughput, versatile, and maskless patterning of different atomic layers. Taking graphene and molybdenum disulfide monolayers as examples, the team shows that both thermal oxidation and sublimation in the light-directed temperature field can lead to direct etching of the atomic layers. They further demonstrates programmable patterning of 2D materials into complex and large-scale nanostructures by steering the laser beam.
Aug 14th, 2018
Researchers report a new a method to produce optical nanostructures on commercial contact lenses. This method aids in functionalizing and nanotexturing an of the shelf, commercial contact lens. This adds to the trend of the humble contact lens, widely used to correct common vision problems, being on its way to become a 'smart' diagnostic tool. Tears contain diagnostic information regarding ocular diseases, and they can be used as a surrogate medium for analyzing blood chemistry.
Apr 30th, 2018
Well-defined complex nanostructures for metamaterials with unique optical properties - such as negative refractive index, strong artificial optical activity and perfect absorption - are usually prepared by top-down approaches, including direct laser writing, multiple e-beam lithography, and membrane projection lithography. In a recent breakthrough, scientists have combined block copolymer self-assembly and an anodized aluminum oxide template to fabricate unique complex nanostructures over a large (centimeter) area.
Apr 26th, 2018