相关论文: Hot Electron Dynamics in Ultrafast Multilayer Epsi…
A new design of a microwave-range ENZ metamaterial consisting of rods with an obround cross-section is proposed. The plasma frequency of the metamaterial can be tuned by rotating the constituent meta-atoms. Tunability of the plasma…
Through the integration of semiconductors or complex oxides into metal resonators, tunable metamaterials have been achieved by a change of environment using an external stimulus. Metals provide high conductivity to realize a strong resonant…
Epsilon-near-zero (ENZ) metamaterial with the relative permittivity approaching zero has been a hot research subject in the past decades. The wave in the ENZ region has infinite phase velocity ($v=1/\sqrt{\varepsilon\mu}$), whereas it…
The femtosecond evolution of the electronic temperature of laser-excited gold nanoparticles is measured, by means of ultrafast time-resolved photoemission spectroscopy induced by extreme-ultraviolet radiation pulses. The temperature of the…
Visualizing ultrafast dynamics at the atomic scale requires time-resolved pump-probe characterization with femtosecond temporal resolution. For single-shot ultrafast electron diffraction (UED) with fully relativistic electron bunch probes,…
Manipulating intensity, phase and polarization of the electromagnetic fields on ultrafast timescales is essential for all-optical switching, optical information processing and development of novel time-variant media. Noble metal based…
The femtosecond optical pump-probe technique was used to study dynamics of photoexcited electrons and coherent optical phonons in transition metals Zn and Cd as a function of temperature and excitation level. The optical response in time…
Electrons in polar liquids give rise to a polaron resonance at a terahertz (THz) frequency \nu_0 depending on electron concentration. The impact of this resonance on light propagation is studied in experiments, where a femtosecond pump…
We verify the feasibility of the proposed theoretical strategy for designing the broadband near-zero permittivity (ENZ) metamaterial at optical frequency range with numerical simulations. In addition, the designed broadband ENZ stack are…
We investigate second harmonic generation, low-threshold multistability, all-optical switching, and inherently nonlocal effects due to the free-electron gas pressure in an epsilon-near-zero (ENZ) metamaterial slab made of cylindrical,…
In past decades, ultrafast spin dynamics in magnetic systems have been associated with heat deposition from high energy laser pulses, limiting the selective access to spin order. Here we use a long wavelength terahertz pump optical probe…
We present a multifunctional on-chip optical device utilizing epsilon-near-zero (ENZ) metamaterials, allowing precise beam control through phase modulation. This design acts as both an all-optical switch and a tunable beam splitter,…
We propose a method for engineering thermally excited far field electromagnetic radiation using epsilon-near-zero metamaterials and introduce a new class of artificial media: epsilon-near-pole metamaterials. We also introduce the concept of…
We analyze ultrafast electron dynamics in the time domain upon optical excitation of propagating surface plasmon-polaritons (SPs) in metal-dielectric heterostructures. Developing a kinetic model where both local and non-local electron…
Plasmonic nanoantennas offer new avenues to manipulate the propagation of light in materials due to their near field enhancement and ultrafast response time. Here we investigate the epsilon-near-zero (ENZ) response in an L-shaped…
Current advances in ultrafast electron microscopy make it possible to combine optical pumping of a nanostructure and electron beam probing with sub{\aa}ngstrom and femtosecond spatiotemporal resolution. We present a theory predicting that…
Hot electrons dominate the ultrafast ($\sim$fs-ps) optical and electronic properties of metals and semiconductors and they are exploited in a variety of applications including photovoltaics and photodetection. We perform power-dependent…
Optical materials with vanishing dielectric permittivity, known as epsilon-near-zero (ENZ) materials, have been shown to possess enhanced nonlinear optical responses in their ENZ region. These strong nonlinear optical properties have been…
Epsilon-near-zero (ENZ) materials have shown significant potential for nonlinear optical applications due to their ultrafast hot carriers and consequent optical nonlinearity enhancement. Modified poly(3,4-ethylenedioxythiophene) (PEDOT)…
Metals exhibit nonequilibrium electron and lattice subsystems at transient times following femtosecond laser excitation. In the past four decades, various optical spectroscopy and time-resolved diffraction methods have been used to study…