Volume 13 Issue 12, December 2019

The arrival of light-emitting diodes based on new materials is posing challenges for the characterization and comparison of devices in a trusted and consistent manner. Here we provide some advice and guidelines that we hope will benefit the community.

Measurements of the Hong–Ou–Mandel effect in a quantum system with PT-symmetric losses composed of coupled waveguides and single photons produce some counterintuitive results.

A wavelength-size laser cavity with a movable end mirror enables single-mode operation and 25% fractional tuning of a terahertz quantum cascade laser.

Using graphene as the ‘metal’ layer improves the localization accuracy of metal-induced energy transfer by nearly tenfold.

The prospects for improving photon upconversion systems by combining organic dyes and inorganic nanoparticles are reviewed.

A sender and a receiver for continuous-variable quantum key distribution are packed onto separate silicon photonic chips. By using an external 1,550-nm laser, a secret key rate of 0.14 kbps is transmitted over a simulated distance of 100 km in fibre.

Unusual photoemission from graphene is explained by the emission of hot electrons. The findings may lead to integrated photonic devices driven by hot-electron emission.

Responses to high-intensity mid-infrared laser light are theoretically investigated in the Haldane system. It is found that the primary electronic response, optical tunnelling and high-harmonic emission are sensitive to the topological phase of matter.

Terahertz quantum-cascade lasers with over 20% continuous fractional tuning of a single laser mode are now possible thanks to metasurfaces.

Using graphene as the ‘metal’ layer can increase the localization accuracy of metal-induced energy transfer, enabling axial localization of single emitters and measurement of the thickness of lipid bilayers with ångström accuracy.

Freely propagating, locally and globally chiral electric fields are introduced, enabling full control over intensity, polarization and propagation direction of the nonlinear enantio-sensitive optical response of randomly oriented chiral molecules.

The quantum-delayed choice experiment is implemented with multiple entangled photons under Einstein’s locality condition. The wave–particle quantum superposition is realized by controlling the relative phase between the wave and particle states.

A method to map the known tranverse photon spin of electromagnetic surface waves over to bulk modes is enabled thanks to bianisotropy.

Parity–time symmetry in second quantization is demonstrated in an integrated non-Hermitian coupled waveguide structure. A counterintuitive shift of the position of the Hong–Ou–Mandel dip is observed in integrated lossy waveguide structures.