Volume 11 Issue 5, May 2017

There is typically a compromise between speed and efficiency when designing silicon photodiodes. Now, researchers have exploited microstructuring to achieve fast and thin devices that are also efficient.

Hyperbolic metamaterials are shown to enable the emission of Cherenkov radiation from low-energy charged particles travelling at slow speeds. The achievement could lead to new forms of light sources and detectors.

A laser-annealing technique for increasing the dopant concentration in semiconductors, the creation of a glass with second-order optical nonlinearity and the realization of optical topological insulators were highlights at the Japan Society of Applied Physics Spring Meeting.

Applying metamaterial concepts to dielectric systems offers low losses compared with metallic structures. Here, silicon-based metamaterial and nanophotonic advances are reviewed.

A study of single grains of lead halide perovskite reveals the presence of both excitons and free charge carriers.

Researchers use hyperbolic metamaterials to make an integrated Cherenkov light source and relax the electron energy requirements. Radiation covering the visible range and near-infrared is achieved with electron energies of only 0.25–1.4 keV.

A laser–plasma accelerator delivering 5-MeV electrons at kHz repetition rate is demonstrated. It is achieved in the laser-wakefield-acceleration regime by using a multi-mJ laser system delivering near-single-cycle laser pulses of 3.4-fs duration.

By exploiting one-dimensional photonic crystal nanocavities, an ultra-compact indium phosphide-on-silicon laser diode with low current threshold, high wall-plug efficiency and high integrability is demonstrated.

Light-trapping nanoscale holes are exploited to improve the speed and efficiency of silicon photodiodes with intrinsic layers less than 2 μm thick.

Ground-state spin rotations in a nitrogen–vacancy centre in diamond are manipulated within nanoseconds of a near-resonant light field being applied. Pauli quantum gates are demonstrated using the geometric spin preparation and read-out techniques.

Hybrid perovskite crystals are integrated onto silicon wafers enabling fabrication of an X-ray linear detector array. High sensitivity may reduce patient dose in medical imaging applications.

Nanoscopy on a chip makes it possible to perform super-resolution imaging of biological specimens with a wide field-of-view.