Related papers: Second Harmonic Generation Through Backward Raman …
We demonstrate unexpectedly strong second harmonic generation (SHG) in Argon gas by use of spatiotemporally focused (SF) femtosecond laser pulses. The resulting SHG by the SF scheme at a 75 cm distance shows a significantly enhanced…
Plasmas with anisotropic electron velocity distribution functions are needed for the controlled study of kinetic plasma instabilities in the laboratory. We demonstrate that such plasma can be produced using ultrashort laser pulses via…
Proposals to reach the next generation of laser intensities through Raman or Brillouin backscattering have centered on optical frequencies. Higher frequencies are beyond the range of such methods mainly due to the wave damping that…
Electromagnetic radiation at higher harmonics of the plasma frequency ($\omega \sim n\omega_{pe}, n > 2$) has been occasionally observed in type II and type III solar radio bursts, yet the underlying mechanism remains undetermined. Here we…
In this article we provide a practical prescription to harness the rigorous microscopic, quantum level descriptions of light-matter systems provided by Hopfield diagonalisation for quantum description of nonlinear scattering. A general…
Strongly magnetizing a plasma adds a range of waves that do not exist in unmagnetized plasmas and enlarges the laser-plasma interaction (LPI) landscape. In this paper, we use particle-in-cell (PIC) simulations to investigate strongly…
We report the observation of second-harmonic generation in stoichiometric silicon nitride waveguides grown via low-pressure chemical vapour deposition. Quasi-rectangular waveguides with a large cross section were used, with a height of 1…
Topological photonics enables robust light manipulation with third-order optical nonlinearity, yet integrating second-order optical nonlinearity into a topological system faces fundamental challenges: frequency-dependent topological…
Nonlinear crystals are widely used to efficiently generate second or third harmonics, and also for frequency mixing. Generation of multiple cascaded harmonics simultaneously, however, appears much less studied, although supported by the…
The spatio-temporal evolution of nonlinear oscillations in multi-species plasma is revisited to provide more insight into the physics of phase mixing by constructing two sets of nonlinear solutions up to the second order. The first solution…
Vectorial nonlinear optics refers to the investigation of optical processes whose nonlinear polarization (NP) undergoes spin-orbit coupling (SOC) interactions where, in general, the driving light field or the new field generated by the…
High-energy vortex $\gamma$ photons have significant applications in many fields, however, their generation and angular momentum manipulation are still great challenges. Here, we first investigated the generation of vortex $\gamma$ photons…
The generation of high-order harmonics in bulk solids subjected to intense ultrashort laser pulses has opened up new avenues for research in extreme nonlinear optics and light-matter interaction on sub-cycle timescales. Despite significant…
When a high power laser beam irradiates a small aperture on a solid foil target, the strong laser field drives surface plasma oscillation at the periphery of this aperture, which acts as a "relativistic oscillating window". The diffracted…
The ultrafast formation of strongly bound excitons in two-dimensional semiconductors provide a rich platform for studying fundamental physics as well as developing novel optoelectronic technologies. While extensive research has explored the…
Nonlinear processes are often governed by selection rules imposed by the symmetries of the molecular configurations. The most well-known examples include the role of mirror symmetry breaking for the generation of even harmonics, and the…
A new concept for second-harmonic generation (SHG) in an optical nanocircuit is proposed. We demonstrate both theoretically and experimentally that the symmetry of an optical mode alone is sufficient to allow SHG even in centro-symmetric…
Silicon-based nonlinear metasurfaces were implemented only with third-order nonlinearity due to the crystal centrosymmetry and the efficiencies are considerably low, which hinders their practical applications with low-power lasers. Here, we…
The past decade has seen tremendous progress in the production and utilization of vortex and vector laser pulses. Although both are considered as structured light beams, the vortex lasers have helical phase fronts and phase singularities,…
By employing a pump-probe technique for enhanced spectral mapping of the dynamics in nonlinear frequency conversion, we demonstrate that photo-induced second-harmonic generation (SHG) in silicon nitride (Si3N4) microresonators can persist…