Showing Spotlights 17 - 24 of 144 in category All (newest first):
The propagation of light can be radically controlled with tailor-made nanostructures, called photonic crystals. The main feature of such crystals is a forbidden gap: waves with colors within a forbidden range travel only a limited distance - called Bragg length - before being reflected due to Bragg interference. Scientists have discovered a method to tunably steer light deep into photonic crystals, to depths well beyond the Bragg length. By spatially shaping the incident waves, the energy density of the light is enhanced at tunable distances deep inside the crystals.
Apr 22nd, 2021
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
Scientists have created a new way to monitor subtle drug interactions between bacteria and antibiotics. By using a common office inkjet printer, researchers developed a disposable living laser on chip by encapsulating living bacteria inside. Strong laser emissions generated from bacteria inside the droplet will be dramatically enhanced during drug interactions. This breakthrough could enable more sensitive and high-throughput testing using micro-nano laser technology in the near future.
Mar 25th, 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 fabricated photodetectors on paper by mimicking the action of drawing/writing with a pencil on standard paper. The results indicate that this process can be employed with other layered materials like the semiconducting molybdenum disulfide to fabricate electronic devices on paper. There are many layered materials (so called van der Waals materials) that have similar mechanical properties to graphite and thus are susceptible of being cleaved upon mechanical rubbing against paper substrates.
Jul 23rd, 2020
The structure of individual molecules and their properties, such as chirality, are difficult to monitor in real time. It turns out that temporarily bridging molecules together can provide a lens into their dynamics. Scientists now have exposed new pathways for investigating biochemical reactions at the nanoscale. They found that optoplasmonic coupling allows for the detection of biomolecules that approach nanoparticles, while they attach, detach, and interact in a variety of ways. The technique paves the way for many future single-molecule analysis techniques that researchers have only been dreaming about.
May 6th, 2020