Closing in on next-generation atom-thick photonic devices

Phys.org  March 13, 2023 The materials used to make photodetectors often hamper efforts to make improved broadband nanoscale photodetectors. To overcome these difficuties a team of researchers in the US (San Francisco State University, Stanford University) developed a photodetector that has improved sensitivity in the ultraviolet to near-infrared light range. High photoresponsivity at wavelength 400 nm measured at 77 K, which translates into an external quantum efficiency. The 90% rise time of the devices at 77 K is 0.1 ms, suggesting they can operate at the speed of ≈10 kHz. High-performance broadband photodetector with spectral coverage ranging from 380 to 1000 nm was demonstrated. According to […]

New device gets scientists closer to quantum materials breakthrough

Phys.org  June 17, 2022 An international team of researchers (USA – UC Berkeley, University of Nebraska, Argonne National Laboratory, Canada) has found a way to combine the advantages of light and matter at room temperature suitable for finding the global minimum of mathematical formulations at room temperature. They used solution-grown halide perovskite grown under nanoconfinement. This produced exceptional smooth single-crystalline large crystals with great optical homogeneity. Its material properties could enable future studies at room temperature rather than ultracold temperatures. They showed that XY spin lattice with many coherently coupled condensates that can be constructed as a lattice with a […]

Ultra-compact integrated photonic device could lead to new optical technologies

Phys.org  March 17, 2022 In photonic circuits optical isolators are used to prevent light from reentering the system and destabilizing it. But guiding light in one direction often requires large magnets, making these circuits difficult to create on a small scale. By coupling light confined in a nanophotonic waveguide with an atomically thin, two-dimensional semiconductor, a team of researchers in the US (University of Chicago, Argonne National Laboratory) exploited the properties of both the light and the material to guide photons in one direction. They fabricated titanium dioxide waveguides directly on the surface of low-disorder, boron nitride-encapsulated tungsten diselenide (WSe2). […]

A new platform for integrated photonics

Phys.org  August 25, 2021 The quality of photonic integrated circuits are limited due to the high density of crystal defects near growth interface. Researchers in China have fabricated an ultralow loss 4H-SiCOI platform with a record-high-Q factor of 7.1 × 106. The platform was prepared by wafer-bonding than thinning techniques, enabled the same crystalline quality as bulk high-pure 4H-SiC crystal. The high Q resonators were used to demonstrate various nonlinear processes including generation of multiple harmonics up to the fourth order. Broadband frequency conversions, including second-, third-, fourth- harmonic generation have been observed. Using a dispersion-engineered SiC microresonator, Kerr frequency […]