Exceptional points induced by unidirectional coupling in electronic circuits.

Exceptional points in non-Hermitian systems have attracted considerable attention due to their novel applications in several fields such as optics, electronics, and mechanics. Typically, exceptional points are constructed through gain and loss modulation or dissipative coupling within the framework of parity-time symmetry or anti-parity-time symmetry. Recent demonstration of unidirectional coupling in optical resonators to create exceptional points has offered an alternative approach.

Fast selective edge-enhanced imaging with topological chiral lamellar superstructures.

Edge detection is a fundamental operation for feature extraction in image processing. The all-optical method has aroused growing interest owing to its ultra-fast speed, low energy consumption and parallel computation. However, current optical edge detection methods are generally limited to static devices and fixed functionality.

Mechanically Driven Self-Healing MXene Strain Gauges for Overstrain-Tolerant Operation.

Compliant strain gauges are well-suited to monitor tiny movements and processes in the body. However, they are easily damaged by unexpected impacts in practical applications, limiting their utility in controlled laboratory environments. This study introduces elastic microcracked MXene films for mechanically driven self-healing strain gauges.

Electrically tunable planar liquid-crystal singlets for simultaneous spectrometry and imaging.

Conventional hyperspectral cameras cascade lenses and spectrometers to acquire the spectral datacube, which forms the fundamental framework for hyperspectral imaging. However, this cascading framework involves tradeoffs among spectral and imaging performances when the system is driven toward miniaturization. Here, we propose a spectral singlet lens that unifies optical imaging and computational spectrometry functions, enabling the creation of minimalist, miniaturized and high-performance hyperspectral cameras.

Command of three-dimensional solitary waves via photopatterning.

Multidimensional solitons are prevalent in numerous research fields. In orientationally ordered soft matter system, three-dimensional director solitons exemplify the localized distortion of molecular orientation. However, their precise manipulation remains challenging due to unpredictable and uncontrolled generation.

Far-Field Phase-Shifting Structured Light Illumination Enabled by Polarization Multiplexing Metasurface for Super-Resolution Imaging.

The phase-shifting structured light illumination technique is widely used in imaging but often relies on mechanical translation stages or spatial light modulators, leading to system instability, low displacement accuracy, and limited integration feasibility. In response to these challenges, we propose and demonstrate an approach for generating far-field phase-shifting structured light using a polarization multiplexing metasurface. By controlling the polarization states of incident and transmitted light, the metasurface creates a three-step displacement of structured light, eliminating the need to move samples or illumination sources.

Charge Generation Dynamics in Organic Photovoltaic Blends under One-Sun-Equivalent Illumination Detected by Highly Sensitive Terahertz Spectroscopy.

Organic photovoltaic (OPV) devices attain high performance with nonfullerene acceptors by utilizing the synergistic dual channels of charge generation that originate from excitations in both the donor and acceptor materials. However, the specific intermediate states that facilitate both channels are subject to debate. To address this issue, we employ time-resolved terahertz spectroscopy with improved sensitivity (Δ/ < 10), enabling direct probing of charge generation dynamics in a prototypical PM6:Y6 bulk heterojunction system under one-sun-equivalent excitation density.

Microsphere lens array embedded microfluidic chip for SERS detection with simultaneous enhancement of sensitivity and stability.

Surface enhanced Raman spectroscopy (SERS) utilizes the fingerprint features of molecular vibrations to identify and detect substances. However, in traditional single focus excitation scenarios, its signal collection efficiency of the objective is restricted. Furthermore, the uneven distribution of samples on the SERS substrate would result in poor signal stability, while the excitation power is limited to avoid sample damage.

Portable all-in-one microfluidic system for CRISPR-Cas13a-based fully integrated multiplexed nucleic acid detection.

Point-of-care testing of "sample in, answer out" is urgently needed for communicable diseases. Recently, rapid nucleic acid tests for infectious diseases have been developed for use in resource-limited areas, but they require types of equipment in central laboratories and are poorly integrated. In this work, a portable centrifugal microfluidic testing system is developed, integrated with magnetic bead-based nucleic acid extraction, recombinase-assisted amplification and CRISPR-Cas13a detection.

Optically Readable, Physically Unclonable Subwavelength Pixel via Multicolor Quantum Dot Printing for Anticounterfeiting.

We present a secure and user-friendly ultraminiaturized anticounterfeiting labeling technique─the color-encoded physical unclonable nanotag. These nanotags consist of subwavelength spots formed by random combinations of multicolor quantum dots, which are fabricated using a cost-efficient printing method developed in this study. The nanotags support over 170,000 different colors and are inherently resistant to cloning.

Multifunctional Nanocomposite Yield-Stress Fluids for Printable and Stretchable Electronics.

Compliant materials are crucial for stretchable electronics. Stretchable solids and gels have limitations in deformability and durability, whereas active liquids struggle to create complex devices. This study presents multifunctional yield-stress fluids as printable ink materials to construct stretchable electronic devices.

Observation of Chiral Symmetry Breaking in Toroidal Vortices of Light.

In this Letter, we explore the intersection of chirality and recently discovered toroidal spatiotemporal optical vortices (STOVs). We introduce "photonic conchs" theoretically as a new type of toroidal-like state exhibiting geometrical chirality, and experimentally observe these wave packets with controllable topological charges. Unlike toroidal STOVs, photonic conchs exhibit unique chirality-related dynamical evolution in free space and possess an orbital angular momentum correlated with all the dimensions of space-time.

Quantum ghost imaging of a vector field.

Quantum ghost image technique utilizing position or momentum correlations between entangled photons can realize nonlocal reconstruction of the image of an object. In this work, based on polarization entanglement, we experimentally demonstrate quantum ghost imaging of vector images by using a geometric phase object. We also provide a corresponding theoretical analysis.

Robust temporal adiabatic passage with perfect frequency conversion between detuned acoustic cavities.

For classical waves, phase matching is vital for enabling efficient energy transfer in many scenarios, such as waveguide coupling and nonlinear optical frequency conversion. Here, we propose a temporal quasi-phase matching method and realize robust and complete acoustical energy transfer between arbitrarily detuned cavities. In a set of three cavities, A, B, and C, the time-varying coupling is established between adjacent elements.

Wearable and interactive multicolored photochromic fiber display.

Endowing flexible and adaptable fiber devices with light-emitting capabilities has the potential to revolutionize the current design philosophy of intelligent, wearable interactive devices. However, significant challenges remain in developing fiber devices when it comes to achieving uniform and customizable light effects while utilizing lightweight hardware. Here, we introduce a mass-produced, wearable, and interactive photochromic fiber that provides uniform multicolored light control.

Logical rotation of non-separable states via uniformly self-assembled chiral superstructures.

The next generation of high-capacity, multi-task optical informatics requires sophisticated manipulation of multiple degrees of freedom (DoFs) of light, especially when they are coupled in a non-separable way. Vector beam, as a typical non-separable state between the spin and orbital angular momentum DoFs, mathematically akin to entangled qubits, has inspired multifarious theories and applications in both quantum and classical regimes. Although qubit rotation is a vital and ubiquitous operation in quantum informatics, its classical analogue is rarely studied.

Dynamically Modulating the Dissymmetry Factor of Circularly Polarized Organic Ultralong Room-Temperature Phosphorescence from Soft Helical Superstructures.

Achieving circularly polarized organic ultralong room-temperature phosphorescence (CP-OURTP) with a high luminescent dissymmetry factor (g ) is crucial for diverse optoelectronic applications. In particular, dynamically controlling the dissymmetry factor of CP-OURTP can profoundly advance these applications, but it is still unprecedented. This study introduces an effective strategy to achieve photoirradiation-driven chirality regulation in a bilayered structure film, which consists of a layer of soft helical superstructure incorporated with a light-driven molecular motor and a layer of room-temperature phosphorescent (RTP) polymer.

Geometric phase-encoded stimuli-responsive cholesteric liquid crystals for visualizing real-time remote monitoring: humidity sensing as a proof of concept.

Liquid crystals are a vital component of modern photonics, and recent studies have demonstrated the exceptional sensing properties of stimuli-responsive cholesteric liquid crystals. However, existing cholesteric liquid crystal-based sensors often rely on the naked eye perceptibility of structural color or the measurement of wavelength changes by spectrometric tools, which limits their practical applications. Therefore, developing a platform that produces recognizable sensing signals is critical.

Stretchable and Smart Wettable Sensing Patch with Guided Liquid Flow for Multiplexed Perspiration Analysis.

Stretchable sweat sensors have become a personalized wearable platform for continuous, noninvasive health monitoring through conformal integration with the human body. Typically, these devices are coupled with soft microfluidic systems to control sweat flow during advanced analysis processes. However, the implementation of these soft microfluidic devices is limited by their high fabrication costs and the need for skin adhesives to block natural perspiration.

Ultrastretchable Electrically Self-Healing Conductors Based on Silver Nanowire/Liquid Metal Microcapsule Nanocomposites.

Stretchable conductive nanocomposites are essential for deformable electronic devices. These conductors currently face significant limitations, such as insufficient deformability, significant resistance changes upon stretching, and drifted properties during cyclic deformations. To tackle these challenges, we present an electrically self-healing and ultrastretchable conductor in the form of bilayer silver nanowire/liquid metal microcapsule nanocomposites.

Polychromatic Dual-Mode Imaging with Structured Chiral Photonic Crystals.

Optical spatial differentiation is a typical operation of optical analog computing and can single out the edge to accelerate the subsequent image processing, but in some cases, overall information about the object needs to be presented synchronously. Here, we propose a multifunctional optical device based on structured chiral photonic crystals for the simultaneous realization of real-time dual-mode imaging. This optical differentiator is realized by self-organized large-birefringence cholesteric liquid crystals, which are photopatterned to encode with a special integrated geometric phase.