Related papers: Second-Order Nonlinear Response in Centrosymmetric…
Optical antennas made out of materials with hyperbolic dispersion is an alternative approach to realizing efficient subwavelength scatterers and may overcome limitations imposed by plasmonic and all-dielectric designs. Recently emerged…
Nonlinear optics, and particularly second harmonic generation (SHG), is increasingly used in many modern disciplines from material characterization in physical sciences to bio-imaging in medicine and optical signal processing in information…
Frequency conversion processes, such as second- and third-harmonic generation, are one of the most common effects in nonlinear optics which offer many opportunities for photonics, chemistry, material science, characterization, and…
We visualized negative refraction of phonon polaritons, which occurs at the interface between two natural crystals. The polaritons - hybrids of infrared photons and lattice vibrations - form collimated rays that display negative refraction…
Second-order nonlinearity gives rise to many distinctive physical phenomena, e.g., second-harmonic generation, which plays an important role in fundamental science and various applications. Lithium niobate, one of the most widely used…
Nonlinear optical frequency conversion, where optical fields interact with a nonlinear medium to generate new frequencies, is a key phenomenon in modern photonic systems. However, a major challenge with these techniques lies in the…
Since de discovery of graphene, the family of 2-dimensional materials has attracted much recent attention. In this work, the nonlinear optical properties of few-layer MoS2 two-dimensional crystals are studied using femtosecond laser pulses.…
The nonlinear properties of a metamaterial sample composed of double-layer metallic patterns and voltage controllable diodes are experimentally investigated. Second harmonics and spectrum modulations are clearly observed in a wide band of…
By combining analytical and numerical approaches, we study resonantly enhanced second-harmonic generation (SHG) by individual high-index dielectric nanoparticles made of centrosymmetric materials. Considering both bulk and surface…
High-order harmonic generation (HHG) is a fundamental process which can be simplified as the production of high energetic photons from a material subjected to a strong driving laser field. This highly nonlinear optical process contains rich…
Few-layer flakes of hexagonal boron nitride were prepared by ultrasonication of bulk crystals and agglomerated to form thin films. The transmission and reflection spectra of the thin films were measured. The spectral dependences of the…
A dielectric material's response to light is macroscopically described by electric displacement fields due to polarization and susceptibility, but the atomistic origin is light-cycle-driven motion of electron densities in the restoring…
True phase-matched second-harmonic generation in a waveguide of crosslinkable ferroelectric liquid crystals is demonstrated. These materials allow the formation of macroscopically polar structures whose order can be frozen by…
We use ultrafast laser pulses to experimentally demonstrate that the second-order optical response of bulk single crystals of the topological insulator Bi$_2$Se$_3$ is sensitive to its surface electrons. By performing surface doping…
Optical materials with centrosymmetry, such as silicon and germanium, are unfortunately absent of second-order nonlinear optical responses, hindering their developments in efficient nonlinear optical devices. Here, a design with an array of…
We investigate Second Harmonic Generation from individual silicon nanowires and study the influence of resonant optical modes on the far-field nonlinear emission. We find that the polarization of the Second Harmonic has a size-dependent…
Nonlinear light sources are central to a myriad of applications, driving a quest for their miniaturisation down to the nanoscale. In this quest, nonlinear metasurfaces hold a great promise, as they enhance nonlinear effects through their…
In mirror-symmetric systems, there is a possibility of the realization of extended gapless electronic states characterized as nodal lines or rings. Strain induced modifications to these states lead to emergence of different classes of nodal…
Nonlinear metasurfaces have become prominent tools for controlling and engineering light at the nanoscale. Usually, the polarization of the total generated third harmonic is studied. However, diffraction orders may present different…
We have obtained spectra of second-harmonic generation, third harmonic generation, and four-wave mixing from a fishnet metamaterial around its magnetic resonance. The resonant behaviors are distinctly different from those for ordinary…