Formation of quantum fields in nonlinear media with self-action, amplification, and losses

Inna L. Plastun

The transmission spectra of inversionless amplification are investigated. Propagation of a weak probe optical beam through a three-level medium pumped with a microwave strong beam is numerically modeled. Three various schemes of transitions under the conditions providing the amplification of the probe field without inversion are taken to calculate the atomic polarization, which enters the paraxial wave equations. Diffraction and self-action ofbeams due to nonlinear absorption and refraction are properly taken into account. These effects together with linear absorption and refraction form a complex distribution of gain across the beams. As a result the amplified beam acquires ring transverse patterns and slight asymmetry in the frequency characteristics.

Daniel F. Walls, Gerard J Milburn

I. A. Tereshchenko, Olga V. Tikhonova

Abstract The features of exciton formation in planar nanostructures under the action of a nonclassical field under the conditions of Kerr phase modulation are analyzed. Excitations of various exciton channels are enhanced or suppressed depending on the nonlinearity magnitude in the system. The possibility of controlling different excitation channels by varying the frequency detuning of the field relative to the resonant transition is demonstrated, and an analytical formula for determining its optimal value is found. The effect of amplification of even excitation channels has been detected, which is caused by correlations of photons under the action of a field in a state of two-mode squeezed vacuum.

Daniel F. Walls, Gerard J Milburn

Sergey A. Ponomarenko, Soodeh Haghgoo

We show that self-similar optical waves with a kink structure exist in a wide class of resonant nonlinear media, adequately treated in the two-level approximation. The self-similar structure of the present kinks is reflected in the time evolution of the field profile, atomic dipole moment, and one-atom inversion. We develop an analytical theory of such kinks. We show that the discovered kinks are accelerating nonlinear waves, asymptotically attaining their shape and the speed of light. We also numerically explore the formation and eventual disintegration of our kinks due to energy relaxation processes. Thus, the present kinks can be viewed as intermediate asymptotics of the system.

Marek Czachor