相关论文: Extrinsic nonlinear Kerr rotation in topological m…
We report a strong-field detection method for magnetic materials, based on the characterization of crystal time-reversal symmetry through the elliptical dichroism of harmonics. The consistency of the low-order harmonics driven by laser…
It is of fundamental importance but challenging to simultaneously identify atomic and magnetic configurations of two-dimensional van der Waals materials. In this work, we show that the nonreciprocal second-harmonic generation (SHG) can be a…
Nonlinear optical microscopy such as in the optical second-harmonic generation (SHG) modality has become a popular tool today for probing materials in the physical and biological sciences. While imaging and spectroscopy are widely used in…
Optical spectroscopy based on second-order nonlinearity is a critical technique for characterizing two-dimensional (2D) crystals as well as bioimaging and quantum optics. It is generally believed that second-harmonic generation (SHG) in…
Recent experiments and calculations in topological semimetals have observed anomalously strong second-order optical nonlinearity, but yet whether the enhancement also occurs at surfaces of topological semimetals in general remains an open…
Surfaces and interfaces of magnetic nanostructures can reveal rather interesting and unusual properties that differ substantially from those of bulky materials. Here we apply the surface-sensitive method of optical second harmonic…
We extend our previous study of the polarization dependence of the nonlinear optical response to the case of magnetic surfaces and buried magnetic interfaces. We calculate for the longitudinal and polar configuration the nonlinear…
The controlled assembly of twisted 2D structures requires precise determination of the crystal orientation of their component layers. In the established procedure, the second-harmonic generation (SHG) intensity of a noncentrosymmetric layer…
Reflecting the fundamental interactions of polarized light with magnetic matter, magneto-optical effects are well known since more than a century. The emergence of these phenomena is commonly attributed to the interplay between exchange…
Second harmonic generation is a powerful tool directly connected to the symmetry of materials. Phase transitions, lattice rotations or electromagnetic coupling in multiferroic compounds can be revealed by using second harmonic…
We theoretically investigate the second harmonic generation (SHG) of topological insulator surface states in a perpendicular magnetic field. Our theory is based on the microscopic expression of the second-order magneto-optical conductivity…
Since the first observation of second harmonic generation (SHG), there have been extensive studies on this nonlinear phenomenon not only to clarify its physical origin but also to realize unconventional functionalities. Nonetheless, a…
The second-order nonlinear optical (NLO) processes, such as the photogalvanic effect and second-order harmonic generation (SHG), play crucial roles in probing and controlling light-matter interactions for energy and device applications. To…
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…
Time-reversal symmetry, together with space-inversion symmetry, is one of the defining properties of crystals, underlying phenomena such as magnetism, topology and non-trivial spin textures. Transition metal dichalcogenides (TMDs) provide…
We report the observation of optical second harmonic generation (SHG) in single-layer indium selenide (InSe). We measure a second harmonic signal of $>10^3$ $\textrm{cts/s}$ under nonresonant excitation using a home-built confocal…
Nonreciprocal devices that allow the light propagation in only one direction are indispensable in photonic circuits and emerging quantum technologies. Contemporary optical isolators and circulators, however, require large size or strong…
We report on the optical second harmonic generation (SHG) on the 1S exciton-polariton resonance in bulk ZnSe that is subject to an external magnetic field applied perpendicular to the light wave vector $\mathbf k$ (Voigt geometry). For the…
Electrical tuning of second-order nonlinearity in optical materials is attractive to strengthen and expand the functionalities of nonlinear optical technologies, though its implementation remains elusive. Here, we report the electrically…
Optical second-harmonic generation (SHG) is a nonlinear parametric process that doubles the frequency of incoming light. Only allowed in non-centrosymmetric materials, it has been widely used in frequency modulation of lasers, surface…