Ultrafast hot electron dynamics in plasmonic nanostructures: experiments, modelling, design
Metallic nanostructures exhibit localized surface plasmons (LSPs), which offer unprecedented opportunities for advanced photonic materials and devices. Following resonant photoexcitation, LSPs quickly dephase, giving rise to a distribution of energetic …
Evolutionary design of two-dimensional material Fabry–Perot structures for enhanced second harmonic generation
The integration of two-dimensional (2D) materials with resonant photonic structures is seen as a promising direction for enhancing its nonlinear optical response. The design of such heterogeneous resonant structures has often relied on multi-parameter sweeps …
Orbital-angular-momentum fluorescence emission based on photon–electron interaction in a vortex field of an active optical fiber
We develop a model of interaction between photons and electrons in an active vortex field, which can generate a fluorescence spectrum with the characteristics of orbital angular momentum (OAM). In an active optical fiber, our findings generalize the notion of …
Versatile generation and manipulation of phase-structured light beams using on-chip subwavelength holographic surface gratings
Phase-structured light beams carrying orbital angular momentum (OAM) have a wide range of applications ranging from particle trapping to optical communication. Many techniques exist to generate and manipulate such beams but most suffer from bulky …
Electrically controllable diffractive optical elements fabricated by direct laser writing on a carbon nanotube network film
A randomly connected single-walled carbon nanotube (CNT) network film is suggested as an optically homogenous thin film to implement a tunable diffractive optical element with a subwavelength thickness. A Fresnel zone plate (FZP) as a thin-film lens is …
Novel photodynamic therapy using two-dimensional NiPS<sub>3</sub> nanosheets that target hypoxic microenvironments for precise cancer treatment
Photodynamic therapy (PDT) is a highly promising modality against cancer, but its efficacy is severely limited by the low oxygen content in solid tumors. In this study, a smart photosensitive NiPS3 nanosheet was developed to solve the problem of low oxygen to …
Nanogap enhancement of the refractometric sensitivity at quasi-bound states in the continuum in all-dielectric metasurfaces
All-dielectric metasurfaces have great potential as highly sensitive refractometric sensors relying on their spectral shifts because of an extensive range of design flexibilities and their smaller absorption losses than plasmonic platforms. However, …
Unidirectional emission of GaN-on-Si microring laser and its on-chip integration
GaN-based microring lasers grown on Si are promising candidates for compact and efficient light sources in Si-based optoelectronic integration and optical interconnect due to their small footprints, low mode volume, low power consumption, and high modulation …
Wideband and high-efficiency spin-locked achromatic meta-device
Achromatic devices present unique capabilities in efficient manipulation of waves and have wide applications in imaging and communication systems. However, the research of achromatic devices is limited by the narrow bandwidth, low efficiency as well as large …
Spin texture and chiral coupling of circularly polarized dipole field
We show that a circularly polarized electric dipole harbors a near-field concentrated wave which orbits around with an energy flux significantly larger (five orders of magnitudes at ?1 nm radial distance) than far-field radiation. This near-field wave is …
All-optical scattering control in an all-dielectric quasi-perfect absorbing Huygens’ metasurface
In this paper, we theoretically and experimentally demonstrated photothermal nonlinearities of both forward and backward scattering intensities from quasi-perfect absorbing silicon-based metasurface with only ?/7 thickness. The metasurface is efficiently …
Terahertz virus-sized gold nanogap sensor
We demonstrated an ultra-sensitive terahertz virus detection method combined with virus-sized gold nanogaps filled with Al2O3. Large-area high-density 20 nm-gap rectangular loop structures, containing a resonant frequency in the terahertz range, were …
Encoding arbitrary phase profiles to 2D diffraction orders with controllable polarization states
Generating 2D diffraction orders with uniform or tailored intensity distribution is highly desired for various applications including depth perception, parallel laser fabrication and optical tweezer. However, previous strategies lack the abilities to tailor …