相关论文: Observation of Nondegenerate Two-Photon Gain in Ga…
We present femtosecond pump-probe measurements of the nondegenerate (1960$\,$nm excitation and 1176--1326$\,$nm probe) two-photon absorption spectra of 8 $\,$nm GaAs/12$\,$nm Al$_{0.32}$Ga$_{0.68}$As quantum well waveguides. Experiments…
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…
We report the first experimental observations of two-photon emission from semiconductors, to the best of our knowledge, and develop a corresponding theory for the room-temperature process. Spontaneous two-photon emission is demonstrated in…
We investigate the nonlinear optical response of a commercial extended-wavelength In$_{0.81}$Ga$_{0.19}$As photodetector. Degenerate two-photon absorption in the mid-infrared range is observed at room temperature using a quantum cascade…
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…
Recent theoretical and experimental studies have shown that squeezed states of light can be engineered to enhance the resolution of nonlinear optical measurements. Here, we analyze non-degenerate two-photon absorption signals obtained from…
We propose two-mode two-photon microlaser using a single semiconductor quantum dot grown inside a two-mode microcavity. We explore both incoherent and coherent pumping at low temperatures to achieve suitable conditions for two-mode…
We show that two-photon absorption (TPA) in Rubidium atoms can be greatly enhanced by the use of a hollow-core photonic bandgap fiber. We investigate off-resonant, degenerate Doppler-free TPA on the 5S1/2 - 5D5/2 transition and observe 1%…
We use a non-perturbative theoretical approach to the parametric down-conversion (PDC) process, which generates entangled-photon field for an arbitrarily strong pump-pulse. This approach can be used to evaluate multi-point field correlation…
We experimentally and theoretically investigate the non-degenerate two-photon absorption coefficient $\beta(\omega_1,\omega_2)$ in the prototypical semiconductor ZnSe. In particular, we provide a comprehensive data set on the dependence of…
Spectroscopy of gases under high-pressure conditions is of interest in various fields such as plasma physics and astrophysics. Recently, it has also been proposed to utilize a high-pressure noble gas environment as a thermalization medium…
We study a new effect of Cooper-pair-based two-photon gain in semiconductor-superconductor structures, showing broadband enhancement of ultrafast two-photon amplification. We further show that with the superconducting enhancement, at…
Strong two-photon absorption (TPA) in monolayer MoS2 is demonstrated in contrast to saturable absorption (SA) in multilayer MoS2 under the excitation of femtosecond laser pulses in the near infrared region. MoS2 in the forms of monolayer…
We observed two-photon emission signals from the first vibrationally excited state of parahydrogen gas excited coherently by counter-propagating laser pulses. A single narrow-linewidth laser source was used to excite the parahydrogen…
A theoretical and experimental investigation of the intensity noise reduction induced by two-photon absorption in a Er,Yb:Glass laser is reported. The time response of the two-photon absorption mechanism is shown to play an important role…
We introduce a toluene-filled fiber platform for two-photon absorption measurements. By confining both the light and molecular sample inside the 5 $\mu$m hollow core of the fiber, we increase the distance over which the nonlinear…
We investigate the prospects of using two-mode intensity squeezed twin-beams, generated in Rb vapor, to improve the sensitivity of spectroscopic measurements by engaging two-photon Raman transitions. As a proof of principle demonstration,…
The simplest approach to deal with light excitations in direct-gap semiconductors is to model them as a two-band system: one conduction and one valence band. For such models, particularly simple analytical expressions are known to exist for…
We calculated third order non-linear polarization to estimate the two-photon absorption of non-interacting two-level molecules in the transmission-type degenerate pump-probe geometry. The spectral intensity and the phase changes of the…
We calculate the theoretical non-degenerate two photon absorption and three color injected current response tensors for bulk GaAs and Ge$_{1-x}$Sn$_x$ for a range of alloy compositions. In particular, by including a ''pump'' beam we compare…