Volume 13 Issue 10, October 2019

Higher-order topological states that are robust against certain classes of disorder and pinned to lattice corners are now observed in photonics platforms.

The occurrence of Bell non-locality, observations that cannot be explained in terms of local influences, is one of the most remarkable features of quantum theory. A new test of non-locality, tailored for quantum networks, has now been implemented in a network with two independent quantum sources.

Acousto-optical interactions within integrated optics platforms are reviewed with a discussion of the useful chip-based devices such as lasers, amplifiers, filters, isolators and more besides that can result.

A blue emitter based on thermally activated delayed fluorescence is narrowband and efficient.

A low-noise, fast avalanche photodetector that operates in the 1,550 nm telecommunications band provides high sensitivity for data communications applications.

A violation of bilocal inequality is demonstrated with two truly independent light sources delivering entanglements to three nodes. To this end, the locality, measurement independence and quantum source independence loopholes are closed simultaneously.

A higher-order topological phase is demonstrated, manifesting as robust, topologically protected corner modes in a silicon photonics system.

Higher-order topologically protected states, localized to corners of photonic waveguide arrays, are experimentally demonstrated.

Through degenerate Kerr four-wave mixing in ultrahigh-Q crystalline microresonators made of magnesium fluoride, tunable conversion of a compact, low-power telecommunications laser over an entire optical octave from 1,083 nm to 2,670 nm, with signatures of mid-infrared sidebands at almost 4,000 nm, is shown.

The terahertz field-induced changes in the superconducting properties of a Nb₃Sn film are investigated by time- and frequency-resolved terahertz spectroscopy. A gapless superconducting state and symmetry-forbidden odd-order coherent modes are observed.

By using an ultrastable oscillator based on a cryogenic Si cavity, the fractional instability of two Sr optical lattice clocks at 1 s reaches 4.8 × 10⁻¹⁷ and 3.5 × 10⁻¹⁷ through anti-synchronous and synchronous comparisons, respectively.

Intracellular laser particles based on silica-coated semiconductor microcavities with distinct emission wavelengths allow real-time tracking of thousands of cells in a tumour model.