Related papers: Frequency-selective terahertz wave amplification b…
Energy conversion in a physical system requires time-translation invariance breaking according to Noether's theorem. Closely associated with this symmetry-conservation relation, the frequencies of electromagnetic waves are found to be…
Huygens' metasurfaces have demonstrated almost arbitrary control over the shape of a scattered beam, however, its spatial profile is typically fixed at fabrication time. Dynamic reconfiguration of this beam profile with tunable elements…
Modulation of metasurfaces in time gives rise to several exotic space-time scattering phenomena by violating the reciprocity and generation of higher-order frequency harmonics. We introduce a new design paradigm for time-modulated…
We report on the frequency conversions of terahertz (THz) waves at ultrafast time boundaries created via femtosecond laser-induced air-to-plasma phase transitions. Our combined experimental and theoretical approach reveals that the abrupt…
Huygens' metasurfaces have demonstrated the ability to tailor electromagnetic wavefronts with passive low-profile structures. The fundamental constraint enabling passive and ideally lossless solutions is the conservation of the normal real…
Performing simultaneous depth-of-field (DoF) extension and edge enhancement within a single optical element remains a fundamental challenge in advanced imaging. Here, we propose a wavelength-tunable nonlocal Huygens' metasurface capable of…
We introduce the concept and a generic approach to realize Extreme Huygens' Metasurfaces by bridging the concepts of Huygens' conditions and optical bound states in the continuum. This novel paradigm allows creating Huygens' metasurfaces…
Time-varying metamaterials and photonic time crystals offer a powerful route to wave amplification through temporal modulation of material parameters. Here, we experimentally demonstrate amplified up-conversion of free-space electromagnetic…
Recently, a special class of Huygens' surfaces has been proposed which are capable of manipulation of transmitted wavefronts while exhibiting high transparency over a broad range of frequencies. In this work we propose and study a new…
The efficient amplification and lasing of electromagnetic radiation at terahertz (THz) frequencies is a non-trivial task achieved mainly by quantum cascade laser configurations with limited tunability and narrowband functionality. There is…
We demonstrate efficient terahertz (THz) modulation by coupling graphene strongly with a broadband THz metasurface device. This THz metasurface, made of periodic gold slit arrays, shows near unity broadband transmission, which arises from…
Optical metasurfaces have developed as a breakthrough concept for advanced wave-front engineering enabled by subwavelength resonant nanostructures. However, reflection and/or absorption losses as well as low polarisation-conversion…
Metasurfaces are an enabling technology for complex wave manipulation functions, including in the terahertz frequency range, where they are expected to advance security, imaging, sensing, and communications technology. For operation in…
Resonant photonic nanostructures exhibiting enhanced nonlinear responses and efficient frequency conversion are an emergent platform in nonlinear optics. High-index semiconductor metasurfaces with rapidly tuned high-Q resonances enable a…
Spatiotemporal metasurfaces, characterized by dynamic variations in both space and time, enable functionalities unattainable with passive metasurfaces. In this study, we propose a novel concept of parametric metasurfaces capable of…
As 2D materials with subwavelength structures, elastic metasurfaces show remarkable abilities to manipulate elastic waves at will through artificial boundary conditions. However, the application prospects of current metasurfaces may be…
Metasurfaces enable a new paradigm of controlling electromagnetic waves by manipulating subwavelength artificial structures within just a fraction of wavelength. Despite the rapid growth, simultaneously achieving low-dimensionality, high…
Local phase control of electromagnetic wave, the basis of a diverse set of applications such as hologram imaging, polarization and wave-front manipulation, is of fundamental importance in photonic research. However, the bulky, passive phase…
The nonlinear metamaterials have been shown to provide nonlinear properties with high nonlinear conversion efficiency and in a myriad of light manipulation. Here we study terahertz generation from nonlinear metasurface consisting of single…
The strong interaction of light with micro- and nanostructures plays a critical role in optical sensing, nonlinear optics, active optical devices, and quantum optics. However, for wavefront shaping, the required local control over light at…