Analytical solutions for the slowly varying phase as well as the field amplitude are obtained for invariant pulse propagation in resonant absorbing media consisting of interacting two-level atoms. Such media, having many atoms within a cubic wavelength, have been shown to exhibit large frequency chirps in pulse propagation owing to near-dipole–dipole interactions. Departures from hyperbolic-secant pulse envelopes and pulse areas other than 2π have been shown to occur in invariant pulse propagation. We show that self-phase modulation results from the near-dipole–dipole interactions and can cause strong modification of pulse shapes, including temporal narrowing and multipulse behavior.
© 1991 Optical Society of America
Original Manuscript: October 9, 1990
Manuscript Accepted: November 15, 1990
Published: May 1, 1991
C. M. Bowden, R. Inguva, and A. Postan, "Invariant pulse propagation and self-phase modulation in dense media," J. Opt. Soc. Am. B 8, 1081-1084 (1991)