Volume 17 Issue 5, May 2023

Nature Photonics spoke to Hongjie Dai from Stanford University about bioimaging in the second near-infrared (NIR-II) spectral window and its clinical potential.

Exceptionally high secret key generation rates of 64 Mbits^–1 and 115.8 Mbits^–1 over a 10 km optical fibre link have been achieved, thanks to custom-built 14-pixel and 16-pixel superconducting nanowire single-photon detectors, respectively, and the use of fast quantum key distribution transmitters.

The study of a light‒matter fluid of exciton–polaritons confirms the role of an inverse energy cascade in two-dimensional quantum turbulence.

Topological photonics has promised new devices that are resistant to backscattering, leading to lower loss, greater nonlinearity, and smaller footprint. New research shows that in reciprocal photonic crystals, backscattering is unavoidable, implying that breaking reciprocity is essential to leveraging photonic Chern insulators.

This work investigates the real-world value of topological protection in reciprocal photonics. Measurements of propagation losses in the slow-light regime of valley-Hall topological waveguides yield no indications of topological protection against backscattering on structural defects.

The addition of a strong coupling layer allows polariton-based emission from red and green organic light-emitting diodes with high external quantum efficiency up to 10%, linewidth smaller than 20 nm and angle-independent emission, with spectral shifts smaller than 10 nm over a 60° angular tilt.

Single-crystal perovskite LEDs exhibit reduced ion migration and Auger recombination and increased device lifetime. Perovskite single-crystals-based LEDs exhibit a maximum brightness of 86,000 cd m⁻², a peak EQE of 11.2% and T₅₀ lifetime of 12,500 h at an initial luminance of 100 cd m⁻².

A nonlinear optical neural network image sensor based on an image intensifier enables efficient all-optical image encoding for a variety of machine-vision tasks.

A quantum key distribution with a key rate of 115.8 Mb s^–1 is demonstrated over 10 km standard optical fibre. To this end, a high-speed and stable system, an integrated transmitter for low error modulation and multipixel superconducting nanowire single-photon detectors are developed.

In combination with a 2.5-GHz clocked time-bin quantum key distribution system, secret keys are generated at a rate of 64 Mbps over a distance of 10.0 km and at a rate of 3.0 Mbps over a distance of 102.4 km with real-time key distillation.

A stack of longitudinal 2D light sheets provides 3D holographic images with improved depth perception.

All-thermal evaporation enables the fabrication of green perovskite LEDs with a peak external quantum efficiency of 16.4%, and active-matrix displays with high resolution and continuous greyscale information.

3D-RAPID, a scalable computational microscope using 54 cameras, records 3D topographic videos of freely moving organisms over an area of 135 cm² at a spatial resolution of tens of micrometres and at a throughput exceeding 5 gigapixels per second.

The turbulent dynamics of a 2D quantum fluid of exciton–polaritons is measured in a planar AlGaAs microcavity after a pulsed optical excitation. Clear evidence of both the onset of vortex clustering and inverse energy cascade is provided.