The refraction is theoretically considered of ultimately short pulses at interface of two dielectrics that contains a thin film
of nonlinear metamaterial. For the model of metamaterial composed of nanoparticles and magnetic nanocircuits (splitring
resonators) the equations are obtained suitable for describing the coherent responses of such film. The numerical
simulation demonstrates the emergence of oscillatory echo in inhomogeneous system of meta-atoms. It is supposed that
the reported methods are applicable for investigation of thin metamaterial films.
The refraction is theoretically considered of ultra-short pulses at interface of two dielectrics that contains a thin film of
nonlinear material featured by the negative refractive index in a certain frequency band. For the models of meta-material
composed of nanoparticles and magnetic nanocircuits (split-ring resonators), the equations are obtained suitable for describing
the coherent responses: photon echo, optical nutations, and harmonic generation. The numerical simulation
demonstrates the emergence of photon echo in inhomogeneous system of meta-atoms. It is supposed that the reported
methods are applicable for investigation of thin meta-material films.
The polarization and spatio-temporal dynamics of coherent pulses propagating in an active birefringent Kerr non-linear
fiber are discussed basing on the numerical solutions of the fiber effects full set self-consistent system of equations for
the circularly polarized components of a coherent optical pulse coupled to the ensemble of the doped resonance atoms.
The excitation of a thin layer of two-level permanent dipole moment atoms by ultimately short (less than field oscillation
period) electromagnetic pulses (videopulse) is observed. The numerical analysis of matter equations free of rotating wave
approximation and relaxation reveals a strong affect of local field and Stark effect on temporal behavior oftransmitted field.
Specifically it is demonstrated that a dense film irradiated by videopulse emits a short response with a delay much longer
even than the characteristic cooperative time of atom ensemble. It is supposed that the local field in the thin layer of permanent
dipole atoms is able to re-pump the atomic subsystem. The close analogy to nonlinear pendulum motion is discussed.
The propagation of the solitary waves in the resonant birefringent amplifier with linear losses is considered. The birefringent
optical linear medium contains two-level atoms with the upper state degenerated over projection of angular moment. It
is assumed that population of resonance levels of atoms is inverted. The steady state pulse of polarized radiation that is vectonal
generalization of the known π-pulse was analytically found. Numerical simulations demonstrate the formation dynamics
solitary waves originated in birefringent amplifier.
Coherent responses of resonance atom layer to short optical pulse excitation are numerically considered. The inhomogeneous broadening of one-photon transition, the near dipole-dipole interaction, and the substrate dispersion are involved in analysis. Under certain intensity of incident pulses, a strong coherent interaction in the form of sharp spikes of superradiation is observed in transmitted radiation. The Lorentz field correction and the substrate dispersion weaken the effect, providing additional spectral shifts. Specific features of photon echo in the form of multiple echoes to a double
or triple pulse excitation in the presence ofnear dipole-dipole interaction is discussed.
The interaction of both scalar and counter-rotating polarized steady state pulses (SSP) is studied numerically for a medium characterized by nonlinear susceptibilities of the third and the fifth order (a cubic-quintic medium with χ<sub>3</sub>> 0, χ<sub>5</sub> < 0 ). The collision of two plateau-shaped solitons proved to be essentially inelastic: a number of secondary solitary waves elliptically polarized arise as a result of interaction of steady-state pulses.
The effects are observed of propagation of an ultimately short (in one or several oscillation) electromagnetic pulse in a medium whose resonance transition characterized both by diagonal and non-diagonal matrix elements of dipole operator. The Maxwell-Bloch set of equation is employed without the approximation of slowly varying amplitudes. The analog of MacCall and Hahn area theorem is discussed corresponding to the process of the initial ultimately short pulse break up into subpulses. A novel solution is found in the form of a stable solitary bipolar signal, whose pulse area is not zero- non-zero breather.
We have observed numerically a quantum mechanical probability current echo response generated by an ensemble of the drops of Bose-Einstein condensates (BEC) loaded in the cells of optical dual lattice. Echo was excited with the pulses of two-photon optical radiation due to Raman scattering. Echo temporal form and the role of inhomogeneous broadening are discussed.
It is shown numerically that a thin layer of semiconductor quantum dots has a threshold transmission characteristic for the ultrashort incident pulse. Weak pulses mainly reflect from layer while pulses with amplitudes above the threshold mainly transmit. The coherent interaction of optical pulses with the layer of quantum dots causes the forming of peaks of superradiation on the profile of transmitted pulses. The phenomenon is accompanied by rapid temporal evolution of ellipticity and azimuth angle across the pulse duration.
Numerical solutions are obtained of the full self-consistent system of equations for the counter rotating polarization components of the field of short optical pulse propagating in birefringent non-linear fiber and the ensemble of the energy level degenerated dopant resonance atoms implanted in fiber material. In every cross-section of fiber the ellipticity of the polarized wave experiences a complex evolution in time accompanied by rapid changes of the azimuth angle due to interplay of dispersion and Kerr non- linear self- and cross-modulation. The reciprocal effect of the impurities on the traveling pulse causes the oscillations of the pulse envelope able to distort completely the shape of the input signal, while the resonance absorption can drive the birefringence from the non-linear back to linear regime.
A refraction of short pulses by a thin film of atoms at two- photon resonance is numerically considered with the process of third harmonic generation involved in analysis. It is shown that a light pulse, being refracted by a tin film of resonance atoms, decays into subpulses, which number is determined by the energy penetrated in the film. The process depends on the angle of incidence. The variation of the resonance detuning allows compensating Stark effect and creating the preferable conditions for light pulse transmission. The effect of local field is similar in its action to the Stark effect, but its contribution to the frequency shift could be significant only in the media with greater concentration of the resonance atoms.