Ultraslow Kuznetsov-Ma solitons and Ahkmediev breathers in a cold three-state medium exposed to nanosecond optical pulses

Abstract

We investigate the formation of the Kuznetsov-Ma solitons and Ahkmediev breathers in a cold Λ-type three-level atomic system that interacts with a probe field of nanosecond pulse duration and a strong continuous-wave driving field via an electromagnetically induced transparency process. Within the framework of the Hirota equation, exact explicit analytical solutions of these breathers are obtained, showing different amplitude and oscillatory characteristics. Numerical simulations confirm the stability of both types of breathers against non-integrable perturbations that are caused by the nonvanishing decay rates of atomic states. We show that both breathers thus generated can propagate at a quite low group velocity.

Cherenkov radiation emitted by Kuznetsov–Ma solitons

“…Furthermore, higher-order nonlinear effects, such as the spontaneous Raman scattering and selfsteepening terms can also break the spectrum symmetry of breathers [19][20][21]. However, there exists another type of "breathing" wave-Kuznetsov-Ma soliton (KMS) [22,23] that has attracted considerable attention recently [24][25][26][27][28][29][30]. KMS is oscillating due to the coherent interaction with a constant background [24,28].…”

Dynamics of bright optical solitons through a coherent atomic medium

“…Optical solitons are investigated in four and three states coherent atomic media [23]. Attractive subluminal/ superluminal soliton wave propagation phenomena have been predicted and observed in these nonlinear dispersive media [24][25][26][27][28][29][30][31][32][33][34]. Recently many experimental and theoretical researches have been performed to investigate the dynamics of bright optical solitons [35][36][37][38][39].…”