Theory of Coherent Propagation of Short Different - Optical Pulses in Three-Level Absorbers.

H. M. Gibbs, Bouwe Bolger

Leon Armenovich Takhtadzhyan

Marek J. Konopnicki, Joseph H. Eberly

The propagation of two short different-wavelength optical pulses in three-level absorbers is studied. Combined numerical and analytic techniques are used to solve the three-level Maxwell-Bloch equations that provide the semiclassical description of the problem. The electric field in the model studied consists of two copropagating plane waves, each of which is in near resonance with a transition in the absorber. A new conservation law, holding in the absence of relaxation mechanisms, and independent of particular values of fields and detunings, is given. It is an analog of the law expressing conservation of the Bloch vector length known for two-level atoms. The possibility of simultaneous lossless propagation of the two optical pulses is established. New analytic solutions having the form of simultaneous different-wavelength optical solitons have been found. These pairs of solitons are called simultons. In order for simulton propagation to occur, both the pulses and the medium have to be prepared in a manner determined by the medium's physical parameters. The conditions for such preparation are given. Simultons are predicted to be distinct from the single-wavelength multiple-pulse solutions resulting from large-area-pulse breakup known in two-level absorbers, as well as from two-photon self-induced transparency. Results of numerical experiments on different-wavelength simultaneous propagation are also presented and indicate that simultaneous propagation may also be obtained under less stringent conditions than those predicted by the analytic solutions. Evidence of pulse evolution and breakup is seen.

F. P. Mattar, A. Matos, Alain Richard +3 more

The effect of diffraction and dispersion on longitudinal reshaping associated with the simultaneous resonant co‐propagation of two different‐wavelength coherent optical pulses in a homogeneously broadened three‐level medium is reported.

R. F. Malikov

Vasily G. Arkhipkin, Ivan V. Timofeev

The spatial and temporal dynamics of two short pulses propagating in an optically dense medium of resonant three-level Λ-atoms is investigated numerically and analytically. The maximum coherence for the Raman transition due to coherent population trapping. It is shown that, at the initial stage of propagation, the waveforms of such pulses only slightly change along the length of the medium, which may considerably exceed the length of linear absorption for a single weak pulse. As the length of the absorbing medium increases, the energy of the probe (first) pulse is completely transferred into the second (control) pulse.