Cathodoluminescence microscopy is now a well-established and powerful tool for probing the photonic properties of nanoscale materials, but in many cases, nanophotonic materials are easily damaged by the electron-beam doses necessary to achieve reasonable cathodoluminescence signal-to-noise ratios. Two-dimensional materials have proven particularly susceptible to beam-induced modifications, yielding

Holography is a highly desired technology in modern photonics, yet setups for traditional generating methods suffer from complexity and bulky sizes. While metasurface-based holography exhibits advantages of compactness and easy-fabrication, most meta-holograms realized so far exhibit only single functionality, with a few multifunctional ones suffering from imbalances of efficiency and device-thickness

Photonic quantum metrology enables the measurement of physical parameters with precision surpassing classical limits by using quantum states of light. However, generating states providing a large metrological advantage is hard because standard probabilistic methods suffer from low generation rates. Deterministic protocols using non-linear interactions offer a path to overcome this problem, but they

The reliable measurement and accurate control of the temperature within nanophotonic devices is a key prerequisite for their application in both classical and quantum technologies. Established approaches use sensors that are attached in proximity to the components, which only offers a limited spatial resolution and thus impedes the measurement of local heating effects. Here, we, therefore, study an

Augmented and virtual reality (AR/VR) is transforming how humans interact with technology in a wide range of fields and industries, from healthcare and education to entertainment. However, current device limitations have impeded wider integration. Tunable holographic metasurfaces represent a promising platform for revolutionizing AR/VR devices by precisely controlling light at the subwavelength scale

Complex power, also known as alternating current (AC) power, is a well-established concept in an electric circuit composed of resistive and reactive elements. On the other hand, the role of complex power in optics has been elusive. In this work, we reveal that the complex energy and momentum determine the resonance frequency and the decay rate of open cavity resonance, the so-called quasinormal modes

Plasmonic nanocavities with highly localized fields in their nanogaps significantly enhance light–matter interactions at the nanoscale, surpassing the diffraction limit. Strong coupling between a plasmonic nanocavity and a molecule forms hybrid upper and lower branch states, resulting in Rabi splitting (RS) in optical spectra. However, scattering and absorption spectra often fail to unambiguously distinguish

We present a study of hybrid light–matter excitations in cavity QED materials using the Dicke–Ising model as a theoretical framework. Leveraging linear response theory, we derive the exact excitations of the system in the thermodynamic limit. Our results demonstrate that the cavity can localize spin excitations, leading to the formation of bound polaritons, where the cavity acts as an impurity of the

Large language models (LLMs) have gained significant prominence in language processing, demonstrating remarkable performance across a wide range of tasks. Recently, LLMs have been explored in various scientific fields beyond language-based tasks. However, their application in the design of nanophotonic devices remains less explored. Here, we investigate the capabilities of LLMs to address nanophotonic

Photodetectors are crucial for modern technologies such as optical communications, imaging, autonomous vehicles, and machine vision. However, conventional semiconductor-based photodetectors require additional filtering systems due to their broad spectral response, leading to increased costs and complexity. Here, we present a narrow spectral response photodetector using hexagonally arranged plasmonic

In traditional optical imaging, image sensors only record intensity information, and phase information of transparent samples such as cells and semiconductor materials is hard to obtain. Quantitative phase imaging techniques are crucial for obtaining detailed phase information, but current methods often require complex interferometric setups or mechanical adjustments, limiting their practical applicability

Terahertz magneto-plasmonics plays a crucial role in platforms for isolation and sensing applications, operating at terahertz frequencies. In spite of recent efforts to enhance magneto-optic effects using metasurfaces, the mechanism for optimizing these effects remains unclear in the terahertz regime. Here we investigate terahertz magneto-optic effects using 100 nm-thick iron slot antennas with varying

I present my perspective on sensing with quantum light. I summarise the motivations and methodology for identifying quantum enhancements in sensing over a classical sensor. In the real world, this enhancement will be a constant factor and not increase with the size of the quantum probe as is often advertised. I use a limited survey of interferometry, microscopy and spectroscopy to extract the vital

Charge-trapping defects in crystalline solids play important roles in applications ranging from microelectronics, optical storage, sensing and quantum technologies. On one hand, depleting trapped charges in the host matrix reduces charge noise and enhances coherence of solid-state quantum emitters. On the other hand, stable charge traps can enable high-density optical storage systems. Here we report

Thin films provide nanoscale confinement together with compatibility with photonic and microwave architectures, making them ideal candidates for chip-scale quantum devices. In this work, we propose a thin film fabrication approach yielding the epitaxial growth of Eu3+ doped Y2O3 on silicon. We combine two of the most prominent thin film deposition techniques: chemical vapor deposition (CVD) and molecular

Unitarity serves as a fundamental concept for characterizing linear and conservative wave phenomena in both classical and quantum systems. Developing platforms that perform unitary operations on light waves in a universal and programmable manner enables the emulation of complex light–matter interactions and the execution of general-purpose functionalities for wave manipulations, photonic computing

Optical neural networks have demonstrated their potential to overcome the computational bottleneck of modern digital electronics. However, their development towards high-performing computing alternatives is hindered by one of the optical neural networks’ key components: the activation function. Most of the reported activation functions rely on opto-electronic conversion, sacrificing the unique advantages

Among the approaches in three-dimensional (3D) single molecule localization microscopy, there are several point spread function (PSF) engineering approaches, in which depth information of molecules is encoded in 2D images. Usually, the molecules are excited sparsely in each raw image. The consequence is that the temporal resolution has to be sacrificed. In order to improve temporal resolution and ensure

Silicon nitride (SiN) formed via low pressure chemical vapor deposition (LPCVD) is an ideal material platform for on-chip nonlinear photonics owing to its low propagation loss and competitive nonlinear index. Despite this, LPCVD SiN is restricted in its scalability due to the film stress when high thicknesses, required for nonlinear dispersion engineering, are deposited. This stress in turn leads to

Advanced optical technologies, such as next-generation displays and holographic systems, demand high efficiency, lightweight designs, compact dimensions, and compatibility with curved and thin substrates. However, current optical devices for virtual and augmented reality displays, such as surface relief and holographic gratings, face challenges like light scattering, low optical efficiency, and limited

Non-Hermitian photonic wave modulators utilizing exceptional points (EPs) was previously proposed as a potential approach to realize high-performance and compact optical modulators. However, their practical implementation has been restricted by their substantial footprint size limit due to stringent adiabatic conditions near EPs. Here, we demonstrate a principle for efficient wave modulation through

Photonic crystal surface-emitting lasers (PCSELs) are promising light sources with numerous advantages, including vertical emission, single-mode operation, and high output power. However, the fabrication of PCSEL devices requires advanced techniques, such as wafer bonding or epitaxial regrowth, to form a photonic crystal (PhC) structure close to the central waveguide layer. This process is not only

In the past decade, the field of topological photonics has gained prominence exhibiting consequential effects in quantum information science, lasing, and large-scale integrated photonics. Many of these topological systems exhibit protected states, enabling robust travel along their edges without being affected by defects or disorder. Nonetheless, conventional topological structures often lack the flexibility

We propose and experimentally demonstrate a small-mode volume bowtie cavity design for all-optical switching applications using a waveguide-cavity structure that exploits asymmetric Fano resonance lineshapes. The bowtie cavity has a mode volume that is five times smaller than conventional (H0-type) photonic crystal point-defect cavities enabling higher nonlinearity and faster switching. Blue and red-detuned

Mid-infrared (Mid-IR) photodetection and imaging are pivotal across diverse applications, including remote sensing, communication, and spectral analysis. Among these, single-pixel imaging technology is distinguished by its exceptional sensitivity, high resolution attainable through the sampling system, and economic efficiency. The quality of single-pixel imaging primarily depends on the performance

Empowering nanophotonic devices via artificial intelligence (AI) has revolutionized both scientific research methodologies and engineering practices, addressing critical challenges in the design and optimization of complex systems. Traditional methods for developing nanophotonic devices are often constrained by the high dimensionality of design spaces and computational inefficiencies. This review highlights

Intra-system entanglement occurs between non-separable modes within the same system. For optical systems, the various degrees of freedom of light represent different modes, and the potential use of light to create higher dimensional classical entangle states offers a promising potential to drive new technological developments. In this work, we present experimental results demonstrating the orthogonality

Optical encryption offers a powerful platform for secure information transfer, combining low power consumption, high-speed transmission, and intuitive visualization. Metasurfaces, with their unprecedented ability to manipulate light across multiple degrees of freedom within quasi-two-dimensional nanostructures, are emerging as promising devices for advanced encryption. However, encryption capacity

Europium-doped nanocrystals constitute a promising material for a scalable future quantum computing platform. Long-lived nuclear spin states could serve as qubits addressed via coherent optical transitions. In order to realize an efficient spin-photon interface, we couple the emission from a single nanoparticle to a fiber-based microcavity under cryogenic conditions. The spatial and spectral tunability

Accurate and fast characterization of nanostructures using spectroscopic ellipsometry (SE) is required in both industrial and research fields. However, conventional methods used in SE data analysis often face challenges in balancing accuracy and speed, especially for the in situ monitoring on complex nanostructures. Additionally, optical constants are so crucial for accurately predicting structural

The quasi-bound state in the continuum (quasi-BIC) of dielectric metasurface provides a crucial platform for sensing, because its almost infinite Q-factor can greatly enhance the interactions between light waves and the analytes. In this work, we proposed an ultrasensitive all-dielectric metasurface sensor composed of periodic rectangular amorphous silicon pillars on a quartz substrate. By breaking

Littrow diffraction devices are commonly used in the laser field (e.g., laser resonators and spectrometers), where system integration requires larger incidence angles and perfect broadband efficiency. Compared to traditional diffraction devices, which struggle to manipulate light paths under large-angle incidence, metasurfaces has the potential to enhance the broadband efficiency. Despite quasi three-dimensional

A new concept of electrochemically modulated single-molecule localization super-resolution imaging is developed. Applications of single-molecule localization super-resolution microscopy have been limited due to insufficient availability of qualified fluorophores with favorable low duty cycles. The key for the new concept is that the “On” state of a redox-active fluorophore with unfavorable high duty

Optical computing has gained significant attention as a potential solution to the growing computational demands of machine learning, particularly for tasks requiring large-scale data processing and high energy efficiency. Optical systems offer promising alternatives to digital neural networks by exploiting light’s parallelism. This study explores a photonic neural network design using spatiotemporal

It has long been desired to enable global structural optimization of organic light-emitting diodes (OLEDs) for maximal light extraction. The most critical obstacles to achieving this goal are time-consuming optical simulations and discrepancies between simulation and experiment. In this work, by leveraging transfer learning, we demonstrate that fast and reliable prediction of OLED optical properties

Circular dichroism – the spin-selective absorption of light – finds diverse applications in medicine, antennas and microwave devices. In this work, we propose and experimentally demonstrate an ultrathin electronically reconfigurable chiral metasurface which exploits the intrinsic symmetries of the meta-molecule to realize any spin absorption based on the handedness of the chirality chosen. We construct

Understanding and controlling the antiferromagnetic order in multiferroic materials on an ultrafast time scale is a long standing area of interest, due to their potential applications in spintronics and ultrafast magnetoelectric switching. We present an optical pump-terahertz (THz) probe study on multiferroic Eu0.75Y0.25MnO3. The optical pump predominantly excites the d-d transitions of the Mn3+ ions

High resolution imaging represents a relentless pursuit within the field of optical system. Multi-frame super-resolution (SR) is an effective method for enhancing sampling density, while it heavily relies on sub-pixel scale displacement of a bulky camera. Based on the symmetric transformation of quadratic-phase metasurface, we propose scaled transverse translation (STT) utilizing planar optical elements

Thin-film lithium niobate (TFLN) has emerged as a promising platform for integrated photonics due to its exceptional material properties. The application of freeform topology optimization to TFLN devices enables the realization of compact designs with complex functionalities and high efficiency. However, the stringent fabrication constraints of TFLN present significant challenges for optimization,

Optical photons play unique role in transmitting information over long distances. Photonic links by the optical fiber networks compose the backbone of today’s global internet. Such fiber optics can also provide the most cost-effective quantum channels to distribute quantum information across distant stationary nodes in future large-scale quantum networks. This prospect motivates the recent emerging

Color centers in hexagonal boron nitride (hBN) are promising candidates as quantum light sources for future technologies. In this work, we utilize a scattering-type near-field optical microscope (s-SNOM) to study the photoluminescence (PL) emission characteristics of such quantum emitters in metalorganic vapor phase epitaxy grown hBN. On the one hand, we demonstrate direct near-field optical excitation

The W-band is essential for applications like high-resolution imaging and advanced monitoring systems, but high-frequency signal attenuation leads to poor signal-to-noise ratios, posing challenges for compact and multi-channel systems. This necessitates distinct frequency selective surfaces (FSS) on a single substrate, a complex task due to inherent substrate resonance modes. In this study, we use

Hadamard matrices, composed of mutually orthogonal vectors, are widely used in various applications due to their orthogonality. In optical imaging, Hadamard microscopy has been applied to achieve optical sectioning by separating scattering and background noise from desired signals. This method involves sequential illumination using Hadamard patterns and subsequent image processing. However, it typically

The perfect vector vortex beams (PVVBs) have played an important role in various fields due to their advantages of unique vortex features, flexible polarization distribution and multiple degrees of freedom (DoFs). The simultaneous and precise control over multiple DoFs, such as the polarization distribution, beam shape and position which greatly influence various characteristics of PVVBs, holds paramount

As Moore’s law approaches its physical limits, the semiconductor industry has begun to focus on improving I/O density and power efficiency through 2.5D/3D packaging. Heterogeneous integration, which combines integrated circuit blocks from different linewidth processes into a single package, is central to these developments. To ensure stable connections with high yield in the back-end processes, high

The increasing global temperatures have escalated the demand for indoor cooling, thus requiring energy-saving solutions. Traditional approaches often integrate metal layers in cooling windows to block near-infrared (NIR) sunlight, which, albeit effective, lack the broad modulation of visible transmission and lead to heat accumulation due to sunlight absorption. Here, we address these limitations by

Structured light is a widely used 3D imaging method with a drawback that it typically requires a long baseline length between the laser projector and the camera sensor, which hinders its utilization in space-constrained scenarios. On the other hand, the application of passive 3D imaging methods, such as depth from depth-dependent point spread functions (PSFs), is impeded by the challenge in measuring

Ultrafast fibre lasers, characterized by ultrashort pulse duration and broad spectral bandwidth, have drawn significant attention due to their vast potential across a wide range of applications, from fundamental scientific to industrial processing and beyond. As dissipative nonlinear systems, ultrafast fibre lasers not only generate single solitons, but also exhibit various forms of spatiotemporal

We analyze the spatiotemporal solitary waves of a graded-index multimode optical fiber with a parabolic transverse index profile. Using the nonpolynomial Schrödinger equation approach, we derive an effective one-dimensional Lagrangian associated with the Laguerre–Gauss modes with a generic radial mode number p and azimuthal index m. We show that the form of the equations of motion for any Laguerre–Gauss

Dielectric metasurfaces supporting optical resonances have become a promising platform for quantum and nonlinear optics. However, resonant metasurfaces remain limited in their capacity to independently control the behavior of many distinct resonances despite efforts in computational optimization and inverse design. In this work, we overcome longstanding limitations by introducing a generalized rational

Reconnections of spatiotemporal optical vortices have been shown to occur between line vortices. Here, we show that reconnections also occur between spatiotemporal loop vortices in optical waves. As optical loop vortices propagate in a media with spatial diffraction and material group velocity dispersion, unique reconnections occur. The birth and death of loops can occur, with certain loop vortices

Total internal reflection generally occurs at incident angles beyond the critical angle, confining electromagnetic waves in dielectrics with higher refractive indices. In this work, we present a metasurface-based solution to transform such total reflection into high-efficiency transmission. We demonstrate that a phase-gradient antireflection metasurface designed on the dielectric surface not only compensates

Chirality of exciton-polaritons can be tuned by the chirality of photons, excitons, and their coupling strength. In this work, we propose a general analytical model based on coupled harmonic oscillators to describe the chirality of exciton-polaritons. Our model predicts the degree of circular polarization (DCP) of exciton-polaritons, which is determined by the DCPs and weight fractions of the constituent

Photons can be used to either monitor or induce catalysis by acting as photoexcited holes or quasi particles, which aid in water splitting reaction leading to a major step towards sustainable energy. However, the mechanism of catalysis using nanocatalysts under photo-illumination is not fully understood because of the complexity involved in three major steps during the oxygen evolution reaction: photoabsorption

Bound states in the continuum (BICs) are localized states within the radiative continuum that exhibit high quality-factor (Q-factor) resonance, which significantly boosts light–matter interactions. However, out-of-plane radiation losses can arise from inherent material absorption and inevitable technological imperfections during fabrication process. Merging BICs have been introduced as a solution to

Space-time separability is commonly assumed in the theoretical description of laser beams. However, recent progresses have demonstrated that this assumption often breaks down for ultrashort realistic pulses, giving rise to spatio-temporal effects that modify both the spatial and temporal characteristics of the laser field. In this work, we introduce semi-analytical and numerical diffraction integral

In this work, we explore how the optical properties of isotropic materials can be modulated by adjacent anisotropic materials, providing new insights into anisotropic light-matter interactions in van der Waals heterostructures. Using a WS2/ReS2 heterostructure, we systematically investigated the excitation angle-dependent photoluminescence (PL), differential reflectance, time-resolved PL, and power-dependent

Arrays of atomic emitters have proven to be a promising platform to manipulate and engineer optical properties, due to their efficient cooperative response to near-resonant light. Here, we theoretically investigate their use as an efficient metalens. We show that, by spatially tailoring the (subwavelength) lattice constants of three consecutive two-dimensional arrays of identical atomic emitters, one

We report the experimental observation and characterization of Replica Symmetry Breaking (RSB) manifestation while analyzing the transverse intensity profile of laser pulses in filamentation experiments using sapphire crystal and distilled water, excited by a femtosecond laser centered at 800 nm. The RSB arises from the competition between self-focusing and plasma defocusing, subject to local fluctuations

Terahertz (THz) technology has attracted significant global interest, particularly in sensing applications, due to its nonionizing feature and sensitivity to weak interactions. Recently, owing to the advantages of low optical loss and the capability to support both electric and magnetic high-quality factor (high-Q) resonances, dielectric metasurfaces have emerged as a powerful platform for multiscenario