Optics and photonics

Stochastic cooling at optical frequencies is demonstrated in an experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator, substantially increasing the bandwidth of stochastic cooling compared with conventional systems.

Using a sol–gel passivation method, the fabrication of blue InGaN nanorod-LEDs with the highest external quantum efficiency value ever reported for LEDs in the nanoscale is demonstrated.

An anti-reflection structure is used to eliminate all back scattering of light passing through a diffusive medium.

Detection of an axial Higgs mode by quantum pathway interference reveals an unconventional charge density wave phase in RTe₃.

Using a three-layer opto-electronic neural network, direct, clock-less sub-nanosecond image classification on a silicon photonics chip is demonstrated, achieving a classification time comparable with a single clock cycle of state-of-the-art digital implementations.

Electrically controlled quantum confinement of excitons to below 10 nm is achieved in a 2D semiconductor by combining in-plane electric fields with interactions between excitons and free charges.

The control of light–matter interactions as a way to manipulate and synthesize strongly correlated quantum matter is discussed, highlighting a field termed ‘strongly correlated electron–photon science’.

A quantum network formed by three optically connected nodes comprising solid-state qubits demonstrates the teleportation of quantum information between two non-neighbouring nodes, negating the need for a direct connection between them.

Using a compact, particle-beam-driven plasma-based accelerator to accelerate high-quality electron beams that are completely characterized in the six-dimensional phase space, free-electron lasing  is observed with narrow-band amplified radiation in the infrared range.

A simple and power-efficient microcomb source is used to drive complementary metal–oxide–semiconductor silicon photonic engines, a step towards the next generation of fully integrated photonic systems.

Using a patterned waveguide, a Bose–Einstein condensate of polaritons is realized in a bound state in the continuum, with a low condensation threshold density that occurs at a dispersion saddle point.

Light-field control of real and virtual charge carriers in a gold–graphene–gold heterostructure is demonstrated, and used to create a logic gate for application in lightwave electronics.

A study realizes a photonic emulator to probe the temporal evolution of light in a non-Hermitian system, and reports the observation of chiral state transfer without encircling an exceptional point.

A solid-state single-electron qubit platform is demonstrated based on trapping and manipulating isolated single electrons on an ultraclean solid neon surface in vacuum, which performs near the state of the art for a charge qubit.

Two new plasmon modes are observed in macroscopic twisted bilayer graphene with a highly ordered moiré superlattice, the first being the signature of chiral plasmons and the second a slow plasmonic mode around 0.4 electronvolts.

Two-junction TPV cells with efficiencies of more than 40% are reported, using an emitter with a temperature between 1,900 and 2,400 °C, for integration into a TPV system for thermal energy grid storage.

Tunable quantum geometric properties of moiré graphene enable the use of a convolutional neural network to simultaneously decipher the light polarization, power and wavelength in a subwavelength-scale smart device.

A material design strategy and fabrication process is described to produce all-polymer light-emitting diodes with high brightness, current efficiency and good mechanical stability, with applications in skin electronics and human–machine interfaces.

A large focal plane switch array is constructed to steer the laser beam of a LiDAR system, leading to 3D imaging with 16,384 pixels, improving the resolution and coverage of solid-state LiDARs.

Imaging the electron and hole that bind to form interlayer excitons in a 2D moiré material enables direct measurement of its diameter and indicates the localization of its centre of mass.

Shear phenomena in the infrared dielectric response of a monoclinic crystal are shown to unveil a new polariton class termed hyperbolic shear polariton that can emerge in any low-symmetry monoclinic or triclinic system.

Ultrafast electron diffraction is used here to reveal in nickel an almost instantaneous, long-lasting population of anisotropic phonons with angular momentum.

A hybrid algorithm that applies backpropagation is used to train layers of controllable physical systems to carry out calculations like deep neural networks, but accounting for real-world noise and imperfections.

A triple phase transition, where changing a single parameter simultaneously gives rise to metal–insulator, topological and a parity–time symmetry-breaking phase transitions, is observed in non-Hermitian Floquet quasicrystals.

A silicon nitride microresonator is used for coherent phase modulation of a transmission electron microscope beam, with future applications in combining high-resolution microscopy with spectroscopy, holography and metrology.

Using a gravitational-wave detector to  listen for dark matter signatures, a direct search for scalar field dark matter was conducted and new upper limits are set on the coupling constants.

Stable, dissipative optomechanical solitons are realized using optical fields in a whispering gallery mode resonator by balancing the optomechanical nonlinearities with a tailored modal dispersion.

A combination of multiview imaging, structured illumination, reconstruction algorithms and deep-learning predictions realizes spatial- and temporal-resolution improvements in fluorescence microscopy to produce super-resolution images from diffraction-limited input images.

Engineering of the coupling between optical modes in a lithium niobate chip enables the realization of tunable, bi-directional and low-loss electro-optic frequency shifters controlled using only continuous and single-tone microwaves.

The efficiency and operating lifetimes of perovskite light-emitting diodes is improved by using a fluorinated triphenylphosphine oxide additive to control the cation diffusion during film deposition and passivate the surface.

Bloch wavefunctions of two types of hole in gallium arsenide are reconstructed by measuring the polarization of light emitted by collisions of electrons and holes accelerated by a terahertz laser.

Experiments using two coupled optical ring resonators and based on the concept of synthetic dimension reveal non-Hermitian energy band structures exhibiting topologically non-trivial knots and links.

Colour contrast is added to unstained histological samples by using surface plasmon polaritons whose properties depend on the sample’s dielectric constant.

A substantial pathway for energy loss in organic solar cells may be suppressed by engineering hybridization between non-fullerene acceptor triplet excitons and spin-triplet charge transfer excitons.

This Review discusses the state of the art of interface optics—including refractive optics, meta-optics and moiré engineering—for the control of van der Waals polaritons.

Gold nanoflake pairs form by self-assembly in an aqueous ligand solution and offer stable and tunable microcavities by virtue of equilibrium between attractive Casimir forces and repulsive electrostatic forces.

Hyperbolic phonon polaritons that exhibit long-distance, ray-like propagation and oblique wavefronts are described at the surface of an anisotropic bulk crystal.

High-performance optoelectronic devices that operate in the infrared regime at room temperature exhibit wide-range, active and reversible tunability of the operating wavelengths with black phosphorus.

Nonlinearity is shown to induce quantized topological transport via soliton motion; specifically, we demonstrate nonlinear Thouless pumping of photons in waveguide arrays with a non-uniformly occupied energy band.

Lasing in the extreme-ultraviolet range is demonstrated using a laser wakefield accelerator, as a step towards compact X-ray free-electron lasers.

Direct infrared nano-imaging of plasmonic waves in graphene carrying high current density reveals the Fizeau drag of plasmon polaritons by fast-moving quasi-relativistic electrons.

The dynamics of ions within a working lithium-ion battery are examined using optical interferometric scattering microscopy, which allows ion transport to be related to phase transitions and microstructural features.

A quantum microscope obtains signal-to-noise beyond the photodamage limits of conventional microscopy, revealing biological structures within cells that would not otherwise be resolved.

Robust heralded entanglement between two solid-state quantum memories with temporal multiplexing is realized using photons at telecommunication wavelengths.

High-harmonic generation from the Dirac-like surface state of a topological insulator is separated from bulk contributions and continuously tuned by the carrier-envelope phase of the driving lightwave.

A nondestructive detector of photonic qubits, comprising a single ⁸⁷Rb atom trapped in the centre point of two crossed fibre-based optical resonators, is demonstrated.

A deep-learning-based approach using a convolutional neural network is used to synthesize photorealistic colour three-dimensional holograms from a single RGB-depth image in real time, and termed tensor holography.

A reinforcement learning experiment using a programmable integrated nanophotonic processor shows that a quantum communication channel with the environment speeds up the learning process of an agent.