相关论文: Nonlinear processes responsible for mid-infrared a…

The exceptional nonlinearity of alkali-metal vapors enables highly efficient nonlinear optical processes even at relatively low optical intensities. However, such processes have traditionally relied on centimeter-scale vapor cells. Here, we…

We investigate frequency up-conversion of low power cw resonant radiation in Rb vapour as a function of various experimental parameters. We present evidence that the process of four wave mixing is responsible for unidirectional blue light…

We suggest a technique based on the transfer of topological charge from applied laser radiation to directional and coherent optical fields generated in ladder-type excited atomic media to identify the major processes responsible for their…

Directional infrared emission at 1367 and 5230 nm is generated in Rb vapours that are step-wise excited by low-power resonant light. The mid-infrared radiation originating from amplified spontaneous emission on the 5D-6P transition consists…

The extraordinary properties of resonant four-wave mixing of backward waves in doped negative-index materials are investigated. The feasibility of independent engineering of negative refractive index and nonlinear optical response as well…

We report on experimentally observed addition, subtraction and cancellation of orbital angular momentum (OAM) in the process of parametric four-wave mixing that results in frequency up- and down-converted emission in Rb vapour. Specific…

The formation of quasar broad-line region (BLR) clouds via thermal instability in the presence of Alfven heating has been discussed by Goncalves et al. (1993a, 1996). In particular, these studies showed the relevance of Alfven heating in…

It is shown that when relativistically intense ultrashort laser pulses are reflected from the boundary of a plasma with a near-critical density, Doppler frequency shift leads to generation of intense radiation both in the high-frequency, up…

To add the detailed information to the existed knowledge of nonlinear optics field, the nonlinear optical processes of the second and third order have been discussed in their respective susceptibility tensors in the presence of degenerate…

A nonlinear quantum-optical process is considered: emission of photon pairs by the reflecting end of a fiber excited by a standing laser wave. Radiation occurs due to periodic changes in the optical length of the fiber over time. This…

A concept of a family of unique backward-wave photonic devices, such as frequency up and down converting nonlinear-optical mirrors, sensors, modulators, filters and amplifiers is proposed. Novel materials are considered, which support…

The mechanisms responsible for ultraviolet to mid-infrared light generation in sodium vapours two-photon excited with continuous-wave sub-100 mW power resonant laser radiation are elucidated from orbital angular momentum transfer of the…

We demonstrate how the orientation of the Rb cell can significantly affect the intensity and spectral characteristics of both the frequency up- and down-converted fields generated by nonlinear processes in Rb vapour. The efficiency of…

The nonlinear absorption of laser radiation of relativistic intensities in the underdense plasma by a mechanism of stimulated bremsstrahlung of electrons on the ions/nuclei is investigated in the low frequency approximation. Coefficient of…

We report on an investigation of simultaneous generation of several narrow-bandwidth laser-like coherent emissions from nitrogen molecular ions ( ) produced in intense mid-infrared laser fields. With systematic examinations on the…

Nonlinear processes of light scattering on a two-level system near resonance are considered. The problem is reduced to the emission and absorption of an entangled system, formed by a strong resonant field and a two-level system, having a…

The non-linear convection for the THz generation from two-colored lasers are analyzed in the context of the forward Raman scattering. The energy transfer from the lasers to the THz light can be efficient. The possible peak intensity of the…

Electromagnetically induced transparency in an optically thick, cold medium creates a unique system where pulse-propagation velocities may be orders of magnitude less than $c$ and optical nonlinearities become exceedingly large. As a…

Ultrashort long-wave infrared (LWIR) laser pulses can resonantly excite vibrations in N2 and O2 through a two-photon transition. The absorptive, vibrational component of the ultrafast optical nonlinearity grows in time, starting smaller…

Spectral red-shifting of high power laser pulses propagating through underdense plasma can be a source of ultrashort mid-infrared (MIR) radiation. During propagation, a high power laser pulse drives large amplitude plasma waves, depleting…