Measurements are presented of fluctuating millimeter-wave radiation from the Alcator Tokamaks. Its characteristics are 1) rapid modulation, approaching 100% with rise time 3-4 ps 2) very narrow line width < 5 GHz at the plasma frequency 3) extremely large intensity, up to 200 time thermal. These characteristics distinguish this radiation from the steady cpe emission previously documented and ar...

The propagation of modulated light in a 2d nonlinear photonic waveguide is investigated in the framework of diffractive optics. It is shown that the dynamics obeys a nonlinear Schrödinger equation at leading order. We compute the first and second corrector and show that the latter may describe some dispersive radiation through the structure. We prove the validity of the approximation in the int...

We propose an approach for an efficient generation of optical Cherenkov radiation (OCR) in the near-infrared by tailoring the waveguide dispersion for a zero group-velocity mismatching between the radiation and the pump soliton. Based on an As(2)S(3) slot waveguide with subwavelength dimensions, dispersion profiles with four zero dispersion wavelengths are found to produce a phase-matching nonl...

The problem of solitonlike pulse propagation in optical fiber devices with two-component fields is studied. Two examples, viz., propagation of pulses in birefringent optical fibers and in nonlinear couplers, are considered. It is shown that radiation processes play an essential role in the soliton dynamics in two-component field fiber devices. Radiation influences the transformation of the main...

Galaxy clusters are sources of gravitational radiation. The main aim of this paper is to give numerical estimates and theoretical description of the relevant features of the gravitational radiation coming from an appropriate spatial distributions of galaxy clusters. Since no analytical approaches are currently available to describe the strongly nonlinear regime, our numerical approach –combinin...

We use the Riemann-Hilbert problem to study the interaction of the soliton with radiation in the parametrically driven, damped nonlinear Schrödinger equation. The analysis is reduced to the study of a finite-dimensional dynamical system for the amplitude and phase of the soliton and the complex amplitude of the long-wavelength radiation. In contrast to previously utilised Inverse Scattering-bas...

The present paper deals with the study of fluid flow and heat transfer characteristics occurring during the melting process due to a stretching surface in micropolar fluid with thermal radiation. A uniform magnetic field is applied normal to surface. The governing equations representing fluid flow have been transformed into nonlinear ordinary differential equations using similarity transformati...

We report quasi-phase-matched difference-frequency generation of 2.1 pm radiation at room temperature using the & nonlinear coefficient in a periodically poled lithium niobate channel waveguide. A tunable Ti:A1203 laser (ilzO.8 ,um) and a Nd:YAG laser (I = 1.32 pm) were the pump and signal sources, respectively. With 160 mW of 0.81 pm and 1 mW of 1.32 pm radiation coupled into the waveguide, 1....

Internal modes of vector solitons and their radiation-induced damping are studied analytically and numerically in the framework of coupled nonlinear Schrödinger equations. Bifurcations of internal modes from the integrable systems are analyzed, and the region of their existence in the parameter space of vector solitons is determined. In addition, radiation-induced decay of internal oscillations...

Spectrally-isolated narrowband Cherenkov radiation from commercial nonlinear photonic crystal fibers is demonstrated as an ultrafast optical source with a visible tuning range of 485-690 nm, which complementarily extends the near-infrared tuning range of 690-1020 nm from the corresponding femtosecond Ti:sapphire pump laser. Pump-tosignal conversion efficiency routinely surpasses 10%, enabling m...