Related papers: Optical Kerr nonlinearity and multi-photon absorpt…
We report a study of high-order multi-photon absorption, nonlinear refraction, and their anisotropy in four notable mid-infrared \c{hi}(2) crystals: GaP, ZnSe, GaSe and ZGP using the Z- scan method and 2.35-{\mu}m femtosecond pulses with…
The optical nonlinearity of WS2, MoS2 monolayer and few-layer films was investigated using the Z-scan technique with femtosecond pulses from the visible to the near infrared. The dependence of nonlinear absorption of the WS2 and MoS2 films…
Bound- and excited-state electronic nonlinearities in CdS quantum dots have been investigated by Degenerate Four-Wave Mixing (DFWM) and Z-scan techniques in the femtosecond time regime. This QD sample shows Kerr-type nonlinearity for…
We present a method to measure quadratic Terahertz optical nonlinearities in Terahertz time-domain spectroscopy. We use a rotating linear polarizer (a polarizing chopper) to modulate the amplitude of the incident THz pulse train. We use a…
We report a systematic investigation of both three-photon absorption (3PA)spectra and wavelength dispersions of Kerr-type nonlinear refraction in wide-gap semiconductors. The Z-scan measurements are recorded for both ZnO and ZnS with…
A highly efficient, practical approach to high-energy terahertz (THz) generation based on spectrally cascaded optical parametric amplification (THz-COPA) is introduced. The THz wave initially generated by difference frequency generation…
Non-degenerate two-photon absorption (TPA) is investigated in a nanophotonic silicon waveguide in a configuration such that the dispersion of the nonlinear absorption and refraction cannot be neglected. It is shown that a signal wave can…
Two-photon absorption (TPA) is of fundamental importance in super-resolution imaging and spectroscopy. Its nonlinear character allows for the prospect of using quantum resources, such as entanglement, to improve measurement precision or to…
Nonlinear terahertz (THz) spectroscopy relies on the interaction of matter with few-cycle THz pulses of electric field amplitudes up to megavolts/centimeter (MV/cm). In condensed-phase molecular systems, both resonant interactions with…
Advanced photonic materials showing two-photon absorption (2PA) have been widely explored to develop three-dimensional imaging, micro and nanofabrication, all-optical switching, lithography on a nanoscale and many other enabling…
We calculate the third order nonlinear optical response in the Hubbard model within the spin density wave (SDW) mean field ansatz in which the gap is due to onsite Coulomb repulsion. We obtain closed-form analytical results in one dimension…
Four-wave parametric amplification can be extended to the TW/cm$^2$ regime using femtosecond pump pulses to amplify nearly octave spanning pulses with gain $> 20$~mm$^{-1}$, which we call Kerr instability amplification. Cross-polarized wave…
We report the first coherent excitation of intramolecular vibrational modes via the nonlinear interaction of a TeraHertz (THz) light field with molecular liquids. A terahertz-terahertz-Raman pulse sequence prepares the coherences with a…
We report the observation of interband two-photon absorption (TPA) saturation in cadmium sulfide nanocrystals (CdS NCs) under intense femtosecond laser excitation with 1.6-eV photon energy. The observation has been compared to interband TPA…
We investigate the nonlinear optical susceptibilities of Mott insulators with the dynamical mean field approximation. The two-photon absorption (TPA) and the third-harmonic generation (THG) spectra are calculated, and the classification by…
Optically generated terahertz (THz) oscillators have garnered considerable attention in recent years due to their potential for wide tunability and low phase noise. Here, for the first time, a dissipative Kerr microresonator soliton comb…
Highly efficient terahertz (THz) wave sources based on difference frequency generation (DFG) process in nonlinear optical crystals play an important role for the applications of THz wave. In order to find more novel nonlinear crystals, here…
We present a systematic theoretical study of the multi-photon nonlinear optical absorption properties of a $\text{GaAs/A}{{\text{l}}_{x}}\text{G}{{\text{a}}_{1-x}}\text{As}$ based quantum well (QW) structure with Morse confinement potential…
We report a large third order nonlinear optical response of palladium diselenide (PdSe2) films, a two dimensional (2D) noble metal dichalcogenide material. Both open aperture (OA) and closed aperture (CA) Z scan measurements are performed…
Controlling nonequilibrium responses in optically driven quantum materials is essential for advancing applications in energy conversion, ultrafast electronics, and quantum computation. Nonlinear optical spectroscopy serves as a powerful…