Electromagnetically induced transparency of picosecond probe laser pulses

Abstract

The results of a theoretical study of the phenomenon of electromagnetically induced transparency of picosecond probe laser pulses are presented. To be sure, the analysis is carried out for the Ʌ-scheme of inhomogeneously broadened quantum transitions between the levels , and of the 208Pb isotope. It is assumed that the control radiation has a nanosecond duration and the input pulses of the probe and control fields are elliptically polarized. It is shown that a bell-shaped input probe pulse generates two independent elliptically polarized normal modes in the medium. The major axis of the polarization ellipse of one of them (the parallel mode) is parallel to the major axis of the polarization ellipse of the input control field. The major axis of the polar-ization ellipse of the other mode (perpendicular mode) is perpendicular to the major axis of the polarization ellipse of the input control field. Each normal mode is a train of subpulses decreas-ing in intensity, separated by nodal points at which the phases of the field components simulta-neously change abruptly by an amount of The speed of propagation of the parallel mode in the medium is higher than the speed of propagation of the perpendicular mode. But these speeds are significantly less than the speed of the control pulse. Therefore, the perpendicular mode shifts faster than the parallel mode towards the trailing edge of the control pulse, entering the region of absence of the phenomenon of electromagnetically induced transparency and attenuates. It is shown that the process of transferring the energy of the total probe radiation occurs most effi-ciently in the case of opposite directions of elliptical polarizations of the input radiation. The analysis showed that the subpulse structure of the probe radiation is associated with the for-mation of 0-pulse of self-induced transparency, competing with the phenomenon of electro-magnetically induced transparency in the case of a picosecond duration of the input probe radiation.

Speaker

Parshkov Oleg
Yuri Gagarin State Technical University of Saratov, 410054 Saratov, Russia
Russia

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