相关论文: Observation of four-photon absorption and determin…
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…
We investigate the optical Kerr nonlinearity and multi-photon absorption (MPA) properties of DSTMS excited by femtosecond pulses at a wavelengths of 1.43 {\mu}m, which is optimal for terahertz generation via difference frequency mixing. The…
This paper presents three-photon absorption (3PA) measurement results for nine direct-gap semiconductors, including full 3PA spectra for ZnSe, ZnS, and GaAs. These results, along with our theory of 3PA using an 8-band Kane model (4 bands…
We recently demonstrated orders of magnitude enhancement of two-photon absorption (2PA) in direct gap semiconductors due to intermediate state resonance enhancement for photons of very different energies. It can be expected that further…
Exciton, trion and biexciton dephasing rates are measured within the inhomogeneous distribution of an InAs quantum dot (QD) ensemble using two-dimensional Fourier-transform spectroscopy. The dephasing rate of each excitonic state is similar…
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…
Infrared-infrared double resonance measurements of the $\nu_3$ absorption band of $SF_6$ using a $CO_2$ TEA laser radiation have been carried out. The results obtained in the present and in some earlier works are discussed taking into…
In this paper, optical and electronic properties of diamond shaped graphene quantum dots (DQDs) have been studied by employing large-scale electron-correlated calculations. The computations have been performed using the \pi-electron…
We report time resolved studies and measurement of all the components of the third-order nonlinear optical susceptibility of CS2 at 515 nm using degenerate four wave mixing. The use of a pulse of width 450 fs, which is comparable to the…
We present the experimental observation of the symmetric four-photon entangled Dicke state with two excitations $|D_{4}^{(2)}>$. A simple experimental set-up allowed quantum state tomography yielding a fidelity as high as $0.844 \pm 0.008$.…
Using an Electrically Focus Tunable Lens (EFTL), an integrating sphere and a tunable femtosecond-pulse laser (Mai Tai HP), we were able to measure the degenerate two-photon absorption coefficient (in transmission) of CdS and ZnSe in a long…
We present results of a study of four-wave mixing in Rb vapour with highly nonlinear susceptibility, using both homodyne and heterodyne detection. We demonstrate that the spectra have different appearances for media possessing…
Enhancement of optical Kerr nonlinearity for self-action by electro-magnetically induced transparency in a four-level atomic system including dephasing between the ground states is studied in detail by solving the density matrix equations…
Two-photon excitation in the near-infrared (NIR) of colloidal nanocrystalline silicon quantum dots (nc-SiQDs) with photoluminescence also in the NIR has the potential to open up new opportunities in the field of deep biological imaging.…
The full time-dependent four-wave mixing polarization in quantum dots is microscopically calculated, taking into account acoustic phonon-assisted transitions between different exciton states of the dot. It is shown that quite different…
This work presents epitaxial growth and optical spectroscopy of CdTe quantum dots (QDs) in (Cd,Zn,Mg)Te barriers placed on the top of (Cd,Zn,Mg)Te distributed Bragg reflector. The formed photonic mode in our half-cavity structure permits to…
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 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…
Ultracold Rb atoms were used to demonstrate non-degenerate four-wave mixing through a Rydberg state. Continuous 5S-5P-nD two-photon excitation to the Rydberg state was combined with an nD-6P tuned laser in a phase matched geometry. The…
Thin films of CdTe were deposited on glass substrates by thermal evaporation. From the XRD measurements itis found that the films are of zinc-blende-type structure. Transmittance, absorption, extinction, and refractive coefficients are…