Science Daily April 20, 2018 An international team of researchers (Spain, France, Portugal, USA – MIT) has shown that a graphene-insulator-metal heterostructure can overcome energy loss and demonstrate plasmon confinement down to the ultimate limit of the length scale of one atom. This is achieved through far-field excitation of plasmon modes squeezed into an atomically thin hexagonal boron nitride dielectric spacer between graphene and metal rods. A theoretical model that takes into account the nonlocal optical response of both graphene and metal is used to describe the results. These ultraconfined plasmonic modes, addressed with far-field light excitation, enable a route […]
Category Archives: Optics
Generating energy from fluctuations of light
Phys.org March 27, 2018 Researchers in Sweden have developed a method and a material that generates an electrical impulse when the light fluctuates from sunshine to shade and vice versa. They created a tiny optical generator by combining the small antennas consisting gold nanodiscs placed on a substrate and coated with a polymeric film to create the pyroelectric properties. The antennas generate heat that is then converted to electricity with the aid of the polymer. The degree of polarisation of the polymer affects the magnitude of the generated power, while the thickness not to have any effect at all. Applications […]
Smaller and faster: The terahertz computer chip is now within reach
Science Daily March 25, 2018 Using a Metal-Oxide-Nitride-Oxide-Silicon (MONOS) structure, researchers in Israel have designed a new integrated circuit that uses flash memory technology in microchips. If successful, this technology will enable standard 8-16 gigahertz computers to run 100 times faster and will bring all optic devices closer to the terahertz chip… read more. TECHNICAL ARTICLE
Many colors from a single dot
Science Daily February 19, 2018 The mechanism underlying the tunable emission appears to be very much dependent on the internal structure of the carbon dots, which differs amongst various preparation techniques. An international team of researchers (the Netherlands, China) studied the emission of individual carbon dots and compared it to the emission of the whole sample and showed that the emission colour of the individual carbon dots can be tuned from blue to red by changing the excitation wavelength, suggesting that multiple colour sites are present and active within a single nanoparticle. These findings demonstrate that it is viable to […]
New hole-punched crystal clears a path for quantum light
Science Daily February 15, 2018 Researchers at the University of Maryland created a photonic chip that both generates single photons and steers them around. In the new chip, they etched out thousands of triangular holes in an array that resembled a bee’s honeycomb. Along the center of the device they shifted the spacing of the holes, which opens a different kind of travel lane for the light. The team tested the capabilities of the chip by first changing a quantum emitter from its lowest energy state to one of its two higher energy states. When they used photons from the […]
Breakthrough in controlling light transmission
Physorg February 8, 2018 A team of researchers in the US (UT Austin, City University of New York) has shown that a non-magnetic device free of an external power source can dramatically break transmission symmetry and realize efficient broadband isolation. Using two judiciously designed nonlinear resonators connected through a delay line, they showed that this is the minimal configuration for enabling low-loss one-way transmission over a broad bandwidth. The combined components, which were printed on a circuit board, formed a highly effective, fully passive isolator that provides excellent signal integrity… read more. TECHNICAL ARTICLE
New exotic phenomena seen in photonic crystals
MIT News January 11, 2018 A team of researchers in the US (MIT, Yale University) used a method that made these open systems accessible and found two specific kinds of effects that are distinctive topological signatures of non-Hermitian systems. One of these is a kind of band feature they refer to as a bulk Fermi arc, and the other is an unusual kind of changing polarization emitted by the photonic crystal used for the study. Most of the potential real-world applications for photonic crystals involve open systems, so the new observations made by this team could open new areas of […]