Team develops way to integrate electro-optic modulator device on end faces of a single-mode optical fiber jumper

Phys.org  August 23, 2023 Digitalizing optical signals through electric driving signals, electro-optic modulators (EOMs) are one of the cardinal elements in modern optical communications. Most of current EOM devices are targeting on-chip integrations, which routinely suffer from high coupling losses, complex optical alignments, and single-band operations. Researchers in China integrated a lumped EOM device on the end faces of a single-mode optical fiber jumper for fast amplitude modulations. Taking advantage of the ultrathin and high quality-factor plasmonic metasurfaces, nanofabrication-friendly and highly efficient EO polymers and coupling-free connections with fiber networks, the EOM was demonstrated to allow dual-band operations and high-speed […]

Optical switching at record speeds opens door for ultrafast, light-based electronics and computers

Science Daily  March 22, 2023 Recently, optical switches have been demonstrated using terahertz and ultrafast laser pulses to control the electrical signal and enhance the switching speed to the picosecond and a few hundred femtoseconds time scale. An international team of researchers (USA- University of Arizona, Ohio State University, Germany) used the reflectivity modulation of the fused silica dielectric system in a strong light field to demonstrate the optical switching (ON/OFF) with attosecond time resolution. They presented the capability of controlling the optical switching signal with complex synthesized fields of ultrashort laser pulses for data binary encoding. AccrdingAccording to the […]

Unexpected light behavior may be harnessed to improve optical communications and sensors

Phys.org  April 21, 2022 Waves entering a spatially uniform lossy medium typically undergo exponential intensity decay, arising from either the energy loss or the evanescent penetration during reflection. A team of researchers in the US (NIST, University of Maryland, Texas Tech University, Carnegie Mellon University) proposed and demonstrated exponential decay free wave propagation in a purely lossy medium. They observed up to 400-wave deep polynomial wave propagation accompanied by a uniformly distributed energy loss across a nanostructured photonic slab waveguide with exceptional points. Using coupled-mode theory and fully vectorial electromagnetic simulations they predicted deep wave penetration manifesting spatially constant radiation […]

Light unbound: Data limits could vanish with new optical antennas

UC Berkeley  February 25, 2021 The quantum Hall effect involves electrons confined to a two-dimensional plane subject to a perpendicular magnetic field, but it also has a photonic analogue. Using heterostructures based on structured semiconductors on a magnetic substrate, a team of researchers in the US (UC San Diego, UC Berkeley) introduced compact and integrated coherent light sources of large orbital angular momenta based on the photonic quantum Hall effect. The photonic quantum Hall effect enables the direct and integrated generation of coherent orbital angular momenta beams of large quantum numbers from light travelling in leaky circular orbits at the […]

Researchers develop way to control speed of light, send it backward

Phys.org  April 4, 2019 Controlling the group velocity of an optical pulse typically requires traversing a material or structure whose dispersion is judiciously crafted. Alternatively, the group velocity can be modified in free space by spatially structuring the beam profile. A team of researchers in the US (University of Central Florida, Purdue University) has demonstrated precise and versatile control over the group velocity of a propagation-invariant optical wave packet in free space through sculpting its spatio-temporal spectrum. By jointly modulating the spatial and temporal degrees of freedom, arbitrary group velocities are unambiguously observed in free space above or below the […]

Unlocking the untapped potential of light in optical communications

Phys.org  March 8, 2019 The optical vortex carries the orbital angular momentum of light and can be used to multiplex signals by assigning each signal to a light wave of different momentum. Researchers in Japan designed and fabricated an orbital angular momentum multiplexing/demultiplexing module that could take five independent signals as input. Using a combination of two tiny circuit structures, called a star coupler and an optical-vortex generator, each of the five signals is “encoded” with a unique optical angular momentum. The output signal consists of a combination of the five signals, and the receiver circuit carries out the multiplexing […]