Volume 16 Issue 3, March 2022

A liquid crystal doped with a diarylethene enantiomer can be switched by light into stable reflection states of different colour, creating new opportunities for lasing and labelling.

Homogenized AgBiS₂ nanocrystals with enhanced light absorption have helped realize an ultrathin solar cell with a certified efficiency of 8.85%.

Harnessing birefringence in a photonic chip featuring an array of coupled waveguides brings new opportunities for investigating quantum effects such as bunching and antibunching.

Directional control of the diffusion of excitons is desired for excitonic devices, but being neutrally charged they can’t be transported by applying a bias voltage as for conventional electronic transport. It is now shown that surface acoustic waves can direct the flux of excitons over micrometre distances, even at room temperature.

This Review details the fundamental photonics and thermodynamics concepts that underlie the processes of radiative cooling, and discusses a few emerging directions associated with radiative cooling research.

Polarization-dependent losses shape Hong–Ou–Mandel interference of photon pairs in birefringent waveguides. Seamless tunability of indistinguishable photon coincidences, all the way from enhancement to full suppression, is enabled by an appropriate choice of the observation basis.

By combining scanning tunnelling microscopy and attosecond technologies, the coherent electronic motion generated in molecules by carrier-envelope-phase-stable laser pulses is visualized at ångström-scale spatial resolution and subfemtosecond temporal resolution.

A custom-designed metasurface for sample illumination and light collection in optical coherence tomography overcomes the usual trade off in lateral resolution and depth of field.

New dopant and host materials yield a deep blue phosphorescent organic light-emitting diode with a lifetime exceeding 1,000 h.

Researchers present a cost-effective approach to make electrically driven random lasers, by modifying commercially available laser diodes.

Chiral liquid-crystal materials with optical properties that can be tuned, erased and reversed offer new opportunities in labelling, displays and anti-counterfeiting.

AgBiS₂ nanocrystals with enhanced optical absorption yield efficient ultrathin solar cells.

Researchers exploit Rayleigh waves and associated dynamic strains to control exciton transport in the weak coupling regime at room temperature. The findings may pave the way for new types of excitonic device for applications ranging from communications to energy.

A photonic anomalous Floquet insulator is emulated in a silicon photonic chip. Up to four-photon topologically protected entangled states are generated in a monolithically integrated emitter in ambient conditions through four-wave mixing on top of the edge modes of the insulator.