Phase-mediated long-range interactions of cavity solitons in a semiconductor laser with a saturable absorber

Abstract

We numerically study the dynamics of pairs of cavity solitons in a laser. We show that the solitons interact even at distances much greater than their sizes in the intensity and carrier-densities profile. The interaction is mediated by the phase. In a certain range of initial values of the distance, the solitons adjust their position until they form bound states. There are two such bound states, corresponding to different equilibrium distances, in which the solitons display partial phase locking, that is, their relative phase slowly oscillates as in a phase-entrained state. In those states, the two solitons can be switched on and off independently. For smaller initial distances, only one soliton survives. For larger initial distances, the solitons lock in phase and repel each other up to a distance of about ten soliton diameters

Frequency and Phase Locking of Laser Cavity Solitons

“…This means that the dashed line on the horizontal axis corresponds to regions where the LCS are almost incapable to interact. The situation is similar to what has been observed in numerical simulations for LCS in semiconductor lasers with saturable absorbers and large initial separation distances between the solitons [42]. In our case the LCS reach a distance larger than five soliton diameters at which they do not feel each other any longer.…”

“…1c) [41,21,42]. Early experiments on solitons in LSA using dyes and photorefractives as gain medium were limited to one soliton due Fig.…”

“…Later investigations in a photorefractive oscillator found multiple spatial laser solitons but did not investigate the interaction and phase properties [46]. Recently, there has been strong progress in the realization of spatial laser solitons in semiconductor-based micro-resonators with frequencyselective feedback [47,48,49,50,51,52] and saturable absorption [53,54,55,56,42]. In these systems, a broad transverse area (transverse indicates the plane orthogonal to the cavity axis) is pumped in a marginally stable plano-planar cavity.…”

Periodic and chaotic solitons in a semiconductor laser with saturable absorber

“…These results indicate that the CSs interact at very large distance, much larger than one soliton diameter and even larger than its phase profile [28]. Phase-locking is robust against noise, that was always included in our simulations.…”

Adler synchronization of spatial laser solitons pinned by defects

“…Laser cavity solitons (LCS) are nonlinear self-localized dissipative states that possess both translational and phase invariance. The interaction of LCS leads to phase-locked bound states with well defined phases and separations as predicted for example in the cubic-quintic Complex Ginzburg Landau (CGL) equations for temporal solitons in mode-locked lasers [2][3][4][5][6][7][8] and in models of lasers with saturable absorbers for the spatial case [9][10][11]. Corresponding bound states have been observed experimentally in fiber lasers [12,13].…”