Related papers: Optimal design and quantum limit for second harmon…
Second harmonic generation (SHG), as one of the most significant \c{hi}(2) nonlinear optical processes, plays crucial roles in a broad variety of optical and photonic applications. Designing various delicate schemes to achieve highly…
We present a study of the possibility to significantly enhance the efficiency of high-order harmonic generation (HHG) using few-cycle optical waveforms obtained by superposing two laser pulses of different color delayed optimally relative…
This study presents an investigation of second harmonic generation (SHG) resulting from interaction of radially polarized laser beam propagating in homogeneous, unmagnetized plasma. Lorentz force and continuity equations have been used to…
The recent, rapid advances in nonlinear chipscale nanophotonics in the visible and near-infrared have been largely driven by manipulating the local dielectric environment proximate to decades-old workhorse bulk nonlinear optical materials,…
We report terahertz (THz) second harmonic generation (SHG) in superconductors (SC) with inversion symmetric equilibrium states that forbid even-order nonlinearities. Such SHG signal is observed in single-pulse emission by periodic driving…
We investigate second harmonic (SH) generation in a doubly resonant metamaterial. We show that SH generation can be enhanced when the resonant condition is satisfied for the SH frequency as well as for the fundamental frequency. A unit cell…
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…
Achieving compact and efficient visible laser sources is crucial for a wide range of applications. However traditional semiconductor laser technology faces difficulties in producing high-brightness green light, leaving a green gap in…
Here we employ the quasi-bound state in the continuum (quasi-BIC) resonance in all-dielectric metasurfaces for efficient nonlinear processes in consideration of the backward frequency conversion. We theoretically study the second-harmonic…
Because of the importance of second harmonic generation in some nonlinear media, in this paper, we investigated induced second harmonic generation in diamond where there is no intrinsic second order susceptibility, X(2). The electric field…
High harmonic generation (HHG) is a powerful probe of electron dynamics on attosecond to femtosecond timescales and has been successfully used to detect electronic and structural changes in solid-state quantum materials, including…
High harmonic generation (HHG) is an established means of producing coherent, short wavelength, ultrafast pulses from a compact set-up. Table-top high-harmonic sources are increasingly being used to image physical and biological systems…
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…
Integrating 2D materials onto on-chip photonic devices holds significant potential for nonlinear frequency conversion across various applications. The lack of inversion symmetry in monolayers of transition metal dichalcogenides (TMDs),…
High-harmonic generation (HHG), which is generation of multiple optical harmonic light, is an unconventional nonlinear optical phenomenon beyond perturbation regime. HHG, which was initially observed in gaseous media, has recently been…
High-order harmonic generation (HHG) in solids - the frequency up-conversion of an optical signal - is governed by symmetries. At terahertz (THz) frequencies, HHG is a key technology to access high frequency spectral windows that are…
We study the effective second-harmonic generation (SHG) susceptibility in graded metallic films by invoking the local field effects exactly, and further numerically demonstrate that the graded metallic films can serve as a novel optical…
A theoretical optimization method of high-harmonic-generation (HHG) is developed in the framework of optimal-control-theory (OCT). The target of optimization is the emission radiation of a particular frequency. The OCT formulation includes…
We investigate high-order harmonic generation (HHG) in graphene with a quantum master equation approach. The simulations reproduce the observed enhancement in HHG in graphene under elliptically polarized light [N. Yoshikawa et al, Science…