Optical physics

Nano-optomechanical systems plays an indispensable role in all-optical manipulation of light but high energy losses severely limit their development. Here the authors show ultrafast all-optical manipulation in a sub-5 nm tip-supported optomechanical metasurface.

Resonators are key components in optics. In this work, the authors introduce a class of optical resonators with distinctly different properties from conventional resonators, allowing fundamental design trade-offs to be circumvented.

The origin of the Rayleigh–Jeans distribution associated with light thermalization in optical thermodynamic multimode nonlinear settings is discussed. Here the authors show that due to entropy maximization, this process is universal and is independent of the intricacies of the nonlinearities involved.

Quantum random number generators should ideally rely on few assumptions, have high enough generation rates, and be cost-effective and easy to operate. Here, the authors show an untrusted-homodyne-based MDI scheme that does not rely on i.i.d. assumption and is secure against quantum side information.

Flexible and coherent light generation is of paramount importance to enable new functionalities in integrated silicon photonics. Here the authors, develop an optical parametric oscillator with high conversion efficiency and high output power, based on the third order nonlinearity in a silicon nitride microresonator

Studies on the fractional Schrödinger equation (FSE) remain mostly theoretical, due to the lack of materials supporting fractional dispersion or diffraction. Here, the authors indirectly realized the FSE using two programmable holograms acting as an optical Lévy waveguide.

Frequency-bin qubits get the best of time-bin and dual-rail encodings, but require external modulators and pulse shapers to build arbitrary states. Here, instead, the authors work directly on-chip by controlling the interference of biphoton amplitudes generated in multiple, coherently-pumped ring resonators.

Miniaturized platforms are desirable for terahertz applications. Here the authors demonstrate chip-scale THz generation with controllable waveforms using thin-film lithium niobate.

The authors investigate whether strong light-matter coupling can alter the nonlinear optical response of molecules inside a microcavity. Focusing on electroabsorption as a model third order nonlinearity, they find that apparent discrepancies between experiment and classical transfer matrix modeling arise from dark states in the system and are not a sign of new physics in the strong coupling regime.

The authors present a single-shot 3D imaging approach utilizing carefully designed point clouds projection based on a metasurface device. They show submillimeter depth accuracy and demonstrate the potential for hand gesture detection.

Hybridization of dark optical cavity modes with vibrational states of molecules can alter chemical reactions. Here, the authors use ab-initio methods to shine light on the associated mechanism and highlight the role of the optical mode to redistribute the vibrational energy.

Physical or chemical reactions driven by light absorption are ruled by excited-state multidimensional energy surfaces displaced with respect to the ground state. Here the authors introduce a nonlinear Raman experiment to access an elusive aspect of the excited-state displacements: their sensed directions relative to the ground-state.

There are many possible mechanisms of high-harmonic generation from crystals. Here the authors discuss the role of the Bloch oscillation to nonlinear response of the crystal and harmonic radiation from it.

Here, the authors predict that plasmons in two-dimensional materials with closely located electron and hole Fermi pockets can be amplified when an electrical current bias is applied along the displaced electron-hole pockets, without the need for an external gain medium.

The parity-time symmetry has led to exotic phenomena and fruitful applications in optical systems. In this paper, the authors propose a leaky-wave-enabled anti-parity-time design and realize space-wave harnessing.

The recently demonstrated approaches to fabrication of quantum emitters in silicon result in their random positioning, hindering applications in quantum photonic integrated circuits. Here the authors demonstrate controlled fabrication of telecom-wavelength quantum emitters in silicon wafers by focused ion beams.

Dynamic localization is a method of confining light. Here the authors demonstrate higher-order dynamic localization of photons in a synthetic temporal mesh lattice and discuss the idea of tunable temporal cloaking by combining different-order localizations.

Electromagnetic response of topological materials is described the so called axion electrodynamics which contains additional relations between the fields. Here the authors extend the theory of axion electrodynamics to general optical frequencies and apply it to a realistic topological antiferromagnet.

‘Giant atom’ physics occurs when the size of the atomic system becomes comparable to the wavelength of the light it interacts with. For atoms, such a regime is impossible to reach, however, for artificial atomic systems such ‘giant atom’ physics can be explored. Here, Wang et al demonstrate giant spin ensembles, consisting of magnetic spheres coupled to a microwave waveguide.

Bound states in the continuum can enhance light-matter interactions across a wide range of optical systems. Here, the authors present a design paradigm for creating pairs of bound states whose optical responses can be predictably controlled.

The existing paradigms of system-bath control typically assume that the bath state is unchanged. By using spin defects in diamond, Dasari et al. demonstrate a scheme for controlling the state of the nuclear spin bath via selective measurements of the central qubit as a way of extending the qubit coherence time.

Lead halide perovskites have recently emerged as a promising platform for the study of polariton superfluidity at room temperature. Here the authors report a complete set of quantum fluid phase transitions in both 1D and 2D homogeneous single crystals of CsPbBr₃.

Spin simulators can solve many combinatorial optimization problems that can be represented by spin models, but they are limited to low-dimensional spins. Here the authors propose a simulator of multidimensional spins in arbitrary dimension, using a system of coupled parametric oscillators with a common pump.

Here the authors report the development of a topological nonlinear parametric amplification in a dimerized, Su-Schrieffer-Heeger waveguide. Kerr-induced chiral symmetry breaking is demonstrated, showcasing how nonlinearities may control transitions of topological modes to bulk states.

The authors demonstrate on-the-fly reconfigurable optical trapping of organic polariton condensates which are delocalised over a macroscopic distance from the excitation region, holding great potential for future work on polaritonic lattice physics.

Floquet engineering aims at inducing new properties in materials with light. Here the authors have used pulses of variable durations, to investigate its applicability in the femtosecond domain. Surprisingly, they found that it holds to the few-cycle limit.

Here, the authors integrate a photonic crystal, supporting photonic bound states in the continuum (BICs), with monolayer WSe₂, and leverage the high energy confinement of the BIC modes to demonstrate coherent directional dark exciton emission.

Controlling the high-power laser transmittance is built on the diverse manipulation of multiple nonlinear absorption processes in the nonlinear optical materials. Here, the authors demonstrate the crucial role of hot-carrier effect to tune the nonlinear absorption response in quasi-2D perovskite films.

Many recent studies have explored the response of magnetic systems to circularly polarised light. To achieve this, typically experiments use a birefringent crystal. Here, Yang et al show that any small error in the alignment of the crystal can result in a beam shift, and this shift can lead to spurious signals similar yet unrelated to the electron spin.

Extending the control over topological system will open the doors to both fundamental studies and applications. Here the authors demonstrate thouless topological transport of light in a bulk tunable moiré lattice.

A unified metric to assess the performances of quantum transducers, i.e., converters of quantum information between different physical systems - is still lacking. Here the authors propose quantum capacity as such metric, and use it to investigate the optimal designs of generic quantum transduction schemes.

Achieving optical cryptography scheme with both high capacity and security is highly desirable. Here, authors report a Stokes meta-hologram with a hierarchical encryption strategy that allows vector encryptions to produce depth-masked ciphertexts.

The authors demonstrate a label-free superresolution imaging method by using a hyperbolic material as a substrate for tailored light-matter interactions. The hyperbolic material enhanced scattering, combined with dark-field detection, result in 5.5-fold resolution improvement beyond the diffraction limit.

Under strong laser fields, materials exhibit extreme non-linear optical response, such as high harmonic generation. These higher harmonics provide insights into electron behaviour in materials in sub-laser cycle timescale. Here, Cha et al study higher harmonic generation resulting from the laser driven motion of massless Dirac fermions in graphene.

The optoelectronic performance of lead halide perovskite in highfluence applications are hindered by heterogeneous multi-polaron interactions in the nanoscale. Here, Nishda et al. spatially resolve sub-ns relaxation dynamics on the nanometer scale by ultrafast infrared pumpprobe nanoimaging.

Here the authors develop topological polarization singular lasers that feature paired radiation channels carrying distinct topological properties which leads to single mode lasing with high external quantum efficiency.

Multimode operation would greatly improve the performances of quantum repeaters. Here, the authors demonstrate a fixed-delay atomic frequency comb quantum memory, based on a Y2SiO5 crystal doped with Ytterbium ions, with a time-domain mode capacity of 1250 modes and a bandwidth of 100 MHz.

Here the authors demonstrate spatiotemporal mode-locked dissipative Kerr soliton and enhanced photonic flywheel performances in both the fundamental comb linewidth and DKS timing jitter.

THz imaging and spectroscopy always request even more efficient components. Here the authors, thanks to a modified photoconductive switch that includes a graphene layer, demonstrate a high-speed photoconductive switch without sacrificing the generated power.

Deep understanding of defect physics, excitonic properties and the ultrafast carrier dynamics in the high mobility p-type transparent CuI is vital for its optoelectronic applications. Here, Liu et al. employ a synergistic approach to unveil these fundamental properties.

Dipolar excitons enable large nonlinear interaction but are usually hampered by their weak oscillator strength. Here, the authors demonstrate the strong light-matter coupling of interlayer dipolar excitons having unusually large oscillator strength in bilayer MoS₂ resulting in highly nonlinear dipolar polaritons.

We show frequency domain mirrors that provide reflections of optical mode propagation in the frequency domain. We theoretically investigated the mirror properties and experimentally demonstrate it using polarization and coupled-resonator-based coupling on thin film Lithium Niobate.

Here, the authors integrate measured fabrication constraints in topology optimization to design a highly optimized dielectric nanocavity. The theoretically predicted confinement of light below the diffraction limit is confirmed by near- and far-field spectroscopy.

High-order optical nonlinearities are a key tool in photonics and quantum optics, but their use is hindered by materials’ small intrinsic high-order susceptibility. Here, the authors show how to realize high-order nonlinear processes by combining intrinsic low-order ones in a microcavity.

Slow light effects are interesting for telecommunications and quantum photonics applications. Here, the authors use coupled exciton-surface plasmon polaritons (SPPs) in a hybrid monolayer WSe₂-metallic waveguide structure to demonstrate a 1300-fold reduction of the SPP group velocity.

The use of machine learning to characterise quantum states has been demonstrated, but usually training the algorithm using data from the same state one wants to characterise. Here, the authors show an algorithm that can learn all states that share structural similarities with the ones used for the training.

Experimental studies of the Casimir effect have involved only interactions between two bodies so far. Here, the authors observe a micrometer-thick cantilever under the Casimir force exerted by microspheres from two sides simultaneously.

Fibre-based entanglement distribution represents a key primitive for quantum applications such as QKD. Here, the authors demonstrate it across 248 km of deployed fiber, observing stable detected pair rates of 9 Hz for 110 h.

Successfully controlling an optical signal by a single gate photon would have great applicability for quantum networks and all-optical computing. Here, the authors realise a single-photon transistor in the microwave regime based on superconducting quantum circuits.