Interaction Of Light Pulses Research Articles

Transmission of a few-Cycle Femtosecond Pulse Through an Optically Thin Plate

The article examines the interaction of a few-cycle optical pulse with an optically thin transparent and/or absorbing layer. The reflection of light energy is shown to be nonmonotone depending on layer thickness. The interaction of a few-cycle light pulse with the layer may produce total transparency of the layer for pulses of a certain carrier frequency. Absorption in the layer also has a nonmonotone effect on both reflected and transmitted light energy. The energy absorbed in the layer may decrease with increasing layer absorption coefficient due to the increase of energy reflection from the layer. The layer thickness when the reflected energy is maximized depends on the electrical conductivity of the medium. Under certain conditions, the interaction of the light pulse with the optically thin plate may essentially alter the spectrum of the reflected pulse and, in particular, its absolute phase, which depends on plate thickness. This property can be exploited in applications to generate few-cycle pulses with the required absolute phase.

Pulse Propagation in a Short Nonlinear Graded-Index Multimode Optical Fiber

We present a detailed analysis of the modal properties, dispersive behavior, and nonlinear mode coupling in graded-index multimode fibers (GIMFs), and lay out a simplified form of a generalized nonlinear Schrodinger equation, which can be used to explore the rich nonlinear dynamics related to the propagation and interaction of light pulses in GIMFs in a tractable manner. We also briefly discuss an application of the presented formalism in the study of four-wave mixing in these fibers. While the reported formalism is fairly general, our presentation is mainly targeted at device applications in which short segments of GIMFs are used.

Integrable equations of a few cycle optical pulse propagation

Evolution of the integrable Reduced Maxwell-Bloch equations describing interaction of light pulses with the two-level system in dipole approximation beyond the slow envelopes application is reviewered.

Spectral control over the interaction of ultrashort pulses in fiber lasers

The interaction of light pulses in passively mode-locked fiber lasers operating has been studied. The numerical simulation has been used to demonstrate that a narrow-band selector inserted in a laser cavity allows the character of the interaction to be changed: depending on the detuning of the selector passband from the center of the gain band, ultrashort pulses can both attract and repel one another. Peculiarities of the pulse interaction have been studied at different parameters of the laser system.

Coherent interaction of an electromagnetic field with a medium of two-level particles and with a superconducting current in a Josephson structure

The propagation of electromagnetic pulses in Josephson structures is investigated theoretically. An analogy with interaction of light pulses with a twolevel medium is traced. Under certain conditions the propagation of electromagnetic radiation in a two-level medium and in a Josephson structure is described by the same wave equation.

Role of relaxation in the resonant interaction of light pulses with matter

Conditions for obtaining maximal enhancement of optical lattice vibrations by a train of picosecond light pulses, including its dependence on the relaxation time of a material system, are found by using density matrix formalism.

Interaction of light pulses with matter.: I. A derivation of the Beer—Lambert law

The Beer—Lambert law is derived directly from Schrodinger's equation for the dynamics of a many-absorber block of matter interacting weakly with a light pulse generated by a superposition of one-photon states of the radiation field. The fluorescent response of an absorber at a depth x in the block depends on both the spatial attenuation and phase-shifting of the frequency components comprising the light pulse. In the limit of narrow band-width pulses the Beer—Lambert law is obtained.

Interaction of light pulses with matter: II. A single absorber exposed to a multi-photon pulse

The dynamics of an absorber interacting with light pulses generated by a particular superposition of muti-photon states has been examined. The probability amplitude BI(t) of the fluorescent intermediate state is obtained as a convolution of the pulse-envelope φ ˜ ( t ) with the “decay” amplitude C ˜ s s ( t ) of the intermediate state. However, the explicit expressions for φ ˜ ( t ) and C ˜ s s ( t ) are somewhat more complex than those found for single-photon pulses. For step-function pulses the results go over to those obtained earlier by Mower and Schurr, and exhibit an interesting range of behavior, especially at high intensities. At low intensities the results agree with those found for one-photon pulses, except for near-resonant pulses with about the same relaxation time as that of the molecular excited state. In that case a subtantial difference is found.