Observation of Zero-Degree Pulse Propagation in a Resonant Medium

Eugene Y. C. Lu, L. E. Wood

We give arguments to show that distortionless propagation of zero-degree pulses is possible in an arbitrary degenerate resonant medium in agreement with recent experimental observation. In the case of overlapping Q (2) degeneracy, the analytic closed-form solution with zero area is given. The predicted pulse shape depends in the relative occupation of the degenerate levels and should be observable experimentally.

Alvin Katz, R. R. Alfano

Hari Prakash, G. S. Bhatnagar

H.P. Grieneisen, J. Goldhar, Norman A. Kurnit +2 more

Experiments are described in which low-intensity laser pulses of zero area [∫−∞∞E(z,t) dt=0] are propagated through a degenerate resonantly absorbing medium with greatly reduced absorption. These pulses are constructed either electro-optically or by allowing a non-zero-degree pulse to evolve toward zero area by means of a resonant absorption and reradiation process. We observe the transmission of as much as 65% of the energy of such pulses through a resonant absorber which attenuates the same cw laser by e−αL, with αL ≈ 20.

V. R. Nagibarov, I. A. Nagibarova, N. K. Solovarov +1 more

An analysis is made of the evolution of a light pulse in a two-level resonant medium as a function of the degree of preliminary excitation by another pulse. It is shown that, in addition to self-induced transparancy observed under certain conditions associated with the degree of excitation of the atomic system, resonance scattering is also found due to the existence of macroscopic polarization of the medium. This scattering is not observed when the medium is in a noncoherent state. The transverse reversible relaxation time T * 2 can be determined from the variation of the scattering intensity.

Uwe van Bürck