Efficient second harmonic generation and broad-band photoluminescence from deeply subwavelength and nontoxic nanoparticles is essential for nanophotonic applications. Here, we explore nonlinear optical response from mesoporous Si/SiO_2, SiO_2, and Si …

Gallium phosphide (GaP) offers unique opportunities for nonlinear and quantum nanophotonics due to its wide optical transparency range, high second-order nonlinear susceptibility, and the possibility to tailor the nonlinear response by a suitable choice of …

We demonstrate that AlGaAs thin films and metasurfaces generate a distinct intrinsic nonlinear geometric phase in their second harmonic signals, differing significantly from previous studies on nonlinear dielectric, plasmonic, or hybrid metasurfaces. Unlike …

Commercial production of integrated photonic devices is limited by scalability of desirable material platforms. We explore a relatively new photonic material, AlScN, for its use in electro-optic phase shifting and modulation. Its CMOS-compatibility could …

The linear and nonlinear optical properties of metallic nanoparticles have attracted considerable experimental and theoretical research interest. To date, most researchers have focused primarily on exploiting their plasmon excitation enhanced near-field and …

Reciprocal scatterers necessarily extinguish the same amount of incoming power when excited from opposite directions. This property implies that it is not possible to realize scatterers that are transparent when excited from one direction but that scatter and …

The luminescent nature of plasmonic nanoparticles (NPs) has been intensively investigated in recent years. Plasmon-enhanced electronic Raman scattering and the radiation channels of metallic photoluminescence (PL) involving conventional carrier recombinations …

Sum frequency generation (SFG) has multiple applications, from optical sources to imaging, where efficient conversion requires either long interaction distances or large field concentrations in a quadratic nonlinear material. Metasurfaces provide an essential …

Dielectric metasurfaces have made significant advancements in the past decade for enhancing light–matter interaction at the nanoscale. Particularly, bound states in the continuum (BICs) based on dielectric metasurfaces have been employed to enhance …

Third-harmonic generation (THG) in silicon nitride waveguides is an ideal source of coherent visible light, suited for ultrafast pulse characterization, telecom signal monitoring and self-referenced comb generation due to its relatively large nonlinear …

Nanophotonic structures have shown promising routes to controlling and enhancing nonlinear optical processes at the nanoscale. However, most nonlinear nanostructures require a handling substrate, reducing their application scope. Due to the underwhelming heat …

High-order wave mixing in solid-state platforms gather increasing importance due to the development of advanced lasers and integrated photonic circuit for both classical and quantum information. However, the high-order wave mixing is generally inefficient in …

High-order harmonic generation (HHG) in solids opens new frontiers in ultrafast spectroscopy of carrier and field dynamics in condensed matter, picometer resolution structural lattice characterization and designing compact platforms for attosecond pulse …

Dielectric metasurfaces supporting quasi-bound states in the continuum (qBICs) enable high field enhancement with narrow-linewidth resonances in the visible and near-infrared ranges. The resonance emerges when distorting the meta-atom’s geometry away from a …

Monolayers of transition metal dichalcogenides (TMDCs) demonstrate plenty of unique properties due to the band structure. Symmetry breaking brings second-order susceptibility to meaningful values resulting in the enhancement of corresponding nonlinear …

Dielectric metasurfaces open new avenues in nonlinear optics through their remarkable capability of boosting frequency conversion efficiency of nonlinear optical interactions. Here, a metasurface consisting of a square array of cruciform-shaped silicon …

Quasi-bound states in the continuum (quasi-BICs) offer unique advantages in enhancing nonlinear optical processes and advancing the development of active optical devices. Here, the tunable robust quasi-BICs resonances are experimentally achieved through the …

Platinum diselenide (PtSe_2), classified as a noble metal dichalcogenide, has garnered substantial interest owing to its layer-dependent band structure, remarkable air-stability, and high charge-carrier mobilities. These properties make it highly promising …

The concept of orbital angular momentum (OAM) of light has not only advanced fundamental physics research but also yielded a plethora of practical applications, benefitting from the abundant methods for OAM generation based on linear, nonlinear and combined …

Photonic devices based on ferroelectric domain engineering in thin film lithium niobate are key components for both classical and quantum information processing. Periodic poling of ridge waveguide can avoid the selective etching effect of lithium niobate, …

Topological corner states have been extensively utilized as a nanocavity to increase nonlinear harmonic generation due to their high Q-factor and robustness. However, the previous topological corner states based nanocavities and nonlinear harmonic generation …

The existence of thresholdless vortex solitons trapped at the core of disclination lattices that realize higher-order topological insulators is reported. The study demonstrates the interplay between nonlinearity and higher-order topology in these systems, as …

Bound states in the continuum have recently been utilized in photonic crystal gratings to achieve strong coupling and ultralow threshold condensation of exciton–polariton quasiparticles with atypical Dirac-like features in their dispersion relation. Here, …

J-aggregates are supramolecular assemblies of dyes exhibiting strong absorption and fluorescence with narrow linewidths, as well as large optical nonlinearities, induced by the formation of largely delocalized molecular excitons. The degree of cooperativity …

Bound states in the continuum (BICs) have attracted much attention in the field of nanophotonics owing to their ability to trap photons without loss. Recently, a low-refractive-index (RI) waveguide loaded on a high-RI slab structure was demonstrated to …

Photonics offers unique capabilities for quantum information processing (QIP) such as room-temperature operation, the scalability of nanophotonics, and access to ultrabroad bandwidths and consequently ultrafast operation. Ultrashort pulse sources of quantum …

We develop a fully vectorial and non-paraxial formalism to describe spontaneous parametric down-conversion in nonlinear thin films. The formalism is capable of treating slabs with a sub-wavelength thickness, describe the associated Fabry–Pérot effects, and …

Nonlinear metasurfaces have recently been established as a new platform for generating photon pairs via spontaneous parametric down-conversion. While for classical harmonic generation in metasurfaces a high level of control over all degrees of freedom of …

All-optical modulators hold significant prospects for future information processing technologies for they are able to process optical signals without the electro-optical convertor which limits the achievable modulation bandwidth. However, owing to the …

Raman scattering is sensitive to local temperature and thus offers a convenient tool for non-contact and non-destructive optical thermometry at the nanoscale. In turn, all-dielectric nanostructures, such as silicon particles, exhibit strongly enhanced …

The advancement in material platforms exhibiting strong and robust electro-optic effects is crucial for further progress in developing highly efficient and miniaturized optoelectronic components with low power consumption for modern optical communication …

Miniature spectrometer is powerful tool for scientific research and industrial inspection. Here, we report the fabrication of graded perovskite filters with tunable bandgap and their application in constructing miniature spectrometer. The graded perovskite …