Optics and photonics

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.

Designing efficient photonic neuromorphic systems remains a challenge. Here, the authors develop an in-sensor Reservoir Computing system for multi-tasked pattern classification based on a light-responsive semiconducting polymer (p-NDI) with efficient exciton dissociations, charge trapping capability, and through-space charge-transport characteristics.

Generation and control of short pulse is desired for ultrafast applications. Here the authors demonstrate ultrafast pulse generation using self-evolving photonic crystal that can transition from high loss to low loss state based on dynamic dispersion compensation.

A suppressed energy loss through Dexter energy transfer is crucial to achieve highly efficient blue organic light-emitting diodes. Here, authors synthesize quadrupolar donor-acceptor-donor type thermally activated delayed fluorescence sensitizers and realize device with maximum efficiency of 43.9%.

Luminophores based on clustering-triggered emission have drawn emerging attention in recent years but they tend to be nonluminescent in dilute solution. Here, the authors design novel clusteroluminogens through modification of cyclodextrin (CD) with amino acids to enable clusterization of chromophores in CD-based confined space and realize blue to cyan fluorescence even in the dilute solution.

Quasi-2D halide perovskites are attracting increasing attention for light-emitting devices. Here, the authors demonstrated efficient and stable quasi-2D perovskite LEDs enabled by suppressed phase disproportionation with newly designed organic ligands.

Complex molecules show element- and enantio-specific properties and reactivity. Here the authors demonstrate identification of the element- and enantiomer-selective motion of Ibuprofen molecule using X-ray photons at the carbon K-edge.

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.

The surface localized charges in colloidal quantum dots induce a degradation that limits the electroluminescence performance. Here, Chen et al. propose quantum dots with monmonotonically-graded core/shell/shell structures to boost the device’s performance by reducing the surface-bulk coupling.

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

Knowledge of fundamental properties of lead halide perovskites is crucial for their technological development. Here, authors perform magneto-optical spectroscopy, develop universal scaling laws and offer a predictive picture for interaction energies within photo-generated charge-carrier complexes.

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.

Microcombs are vulnerable to the environmental perturbations. Here, the authors propose a universal mechanism to fully control the microcombs. Based this reconfigurable microsoliton, a wavemeter with a precision of kHz is demonstrated.

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.

Diagnosis of bile duct cancer often occur in advanced stages, leading to poor survival. Here, the authors combine light scattering and diffuse reflectance spectroscopies in a minimally invasive endoscopic technique for directly assessing the malignant potential of the bile duct lining, and demonstrate 97% detection accuracy.

The authors realize longitudinal deep-brain imaging through an intact mouse skull by constructing a high-speed reflection matrix microscope at 1.3 µm wavelength and developing a computational conjugate adaptive optics algorithm eliminating skull aberrations.

Here, the authors investigate the Raman spectra of few-layered WS₂ when the excitation energy is in resonance with the dark exciton, and observe a Fano resonance between dark excitonsand zone-edge acoustic phonons.

Optical neural networks face remarkable challenges in high-level integration and on-chip operation. In this work the authors enable optical convolution utilizing time-wavelength plane stretching approach on a microcomb-driven chip-based photonic processing unit.

Integrating diffractive optical neural networks (DONN) would reduce errors due to bulky components and calibration. Here, the authors exploit integrated 1D dielectric metasurfaces to realise an on-chip DONN device with 90% classification accuracy, computing at 10^16 flops/mm^2 and consuming 10E-17 J/Flop.

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

All-inorganic nanocrystals are of great importance for a variety of electronic applications. Here, the authors use metal salts to remove organic ligands to obtain passivated nanocrystals with improved fluorescence yield for direct optical patterning.

Convolutional operation is a very efficient way to handle tensor analytics, but it consumes a large quantity of additional memory. Here, the authors demonstrate an integrated photonic tensor processor which directly handles high-order tensors without tensor-matrix transformation.

A 3D wide-field fluorescence microscopy method is introduced based on optical astigmatism combined with fluorescence source localization. It enables transcranial cortical microcirculation mapping in murine brain with high spatiotemporal resolution.

The authors present a planar photonic chip, which operate as a multiple-order analog spatial differentiator. It provides a route for designing fast, power-efficient, compact and low-cost devices used in edge detection and optical image processing, thus expanding the functions of standard microscopes.

Traditional learning procedures for artificial intelligence rely on digital methods not suitable for physical hardware. Here, Nakajima et al. demonstrate gradient-free physical deep learning by augmenting a biologically inspired algorithm, accelerating the computation speed on optoelectronic hardware.

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 single-pixel imaging accelerated via swept aggregate patterns (SPI-ASAP), which combines a digital micromirror device with laser scanning for fast and reconfigurable pattern projection, and a lightweight reconstruction algorithm. They demonstrate real-time video streaming at 100 fps, and up to 12,000 fps offline.

Probing the localized electrocatalytic activity of heterogeneous electrocatalysts is crucial. Here, the authors propose a method of imaging the surface charge density and electrocatalytic activity of single two-dimensional electrocatalyst nanosheets.

The authors demonstrate a multi-dimensional communication scheme that combines wavelength- and mode- multiplexing on photonic integrated circuits using foundry-compatible photonic inverse design and spectrally flattened microcombs

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.

The authors present an approach to phase imaging by using the non-local optical response of a guided-moderesonator metasurface. They demonstrate that this metasurface can be added to a conventional microscope to enable quantitative phase contrast imaging.

Structured Illumination Microscopy allows for the visualization of biological structures at resolutions below the diffraction limit, but this imaging modality is still hampered by high experimental complexity. Here, the authors present a combination of interferometry and machine learning to construct a structured illumination microscope for super resolution imaging of dynamic sub-cellular biological structures in multiple colors.

The authors demonstrate programmable integrated microwave photonic filters with low noise figure and ultrahigh dynamic range, using combination of modulation transformer and double injection ring resonator in a single photonic chip.

Here the authors harness the on-chip integration of Jones matrix metasurfaces to demonstrate an ultra-compact approach to access and manipulate the optical spin states of vertical cavity surface-emitting lasers (VCSELs) with previously unattainable phase controllability.

The exciton Mott transition refers to a transition from an insulating state of gas-like excitons to strongly correlated electron-hole plasma phases in photoexcited semiconductors. Here the authors experimentally study such a transition in black phosphorus and reveal its quantum critical properties.

It is currently debated how to reliably distinguish liquid–liquid phase separation (LLPS) from other mechanisms. Here the authors report model-free calibrated half-FRAP (MOCHA-FRAP) to probe the barrier at the condensate interface that is responsible for preferential internal mixing in LLPS.

Light penetration and overheating are major issues facing the application of photothermal therapy. Here, the authors develop a temperature responsive hydrogel optical waveguide for controlled delivery of light to deep tumours and demonstrate biocompatibility and temperature responsive phototherapy in vivo

The authors introduce Bond-selective Intensity Diffraction Tomography, a computational mid-infrared photothermal microscopy technique based on a standard bright-field microscope and an add-on pulsed light source. It recovers both mid-infrared spectra and bond-selective 3D refractive index maps based on intensity-only measurements.

The authors present a wearable photoacoustic patch, which integrates laser diodes and piezoelectric transducers for three-dimensional imaging of hemoglobin and temperature in deep tissues.

Super-resolution microscopy techniques can be challenging for live cells and thick samples. Here, the authors propose a method to reduce beam intensity and remove out-of-focus fluorescence background in image-scanning microscopy (ISM) and its combination with stimulated emission depletion (STED).

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 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.

Applications of ultra-low-loss photonic circuitry in quantum photonics, in particular including triggered single photon sources, are rare. Here, the authors show how InAs quantum dot single photon sources can be integrated onto wafer-scale, CMOS compatible ultra-low loss silicon nitride photonic circuits.

A 300-Gbit/s free-space optical communication system is demonstrated in the mid-IR wavelength region by using both wavelength- and mode-division multiplexing.

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.

The authors presented an ultrahigh-responsivity phototransistor with a thin InGaAs film on a silicon waveguide. The effective gating by the silicon waveguide enables 10⁶ A/W responsivity, promising for optical power monitors in Si photonic circuits.

The authors developed an optical-fiber-based photoacoustic endoscope for gastroenterology. It can noninvasively view the internal vascular structures and visualize the hemodynamic response in a lesion.