Rl. Davidchack et al., Regular dynamics of low-frequency fluctuations in external cavity semiconductor lasers - art. no. 056206, PHYS REV E, 6305(5), 2001, pp. 6206
It is commonly believed that the dynamics responsible for low-frequency flu
ctuations (LFF's) in external cavity semiconductor lasers is stochastic or
chaotic. A common approach to address the origin of LFF's is to investigate
the dynamical behavior of, and the interaction among, various external cav
ity modes in the Lang-Kobayashi (LK) paradigm. In this paper, we propose a
framework for understanding of the LFFs based on a different set of fundame
ntal solutions of the LK equations, which are periodic or quasiperiodic, an
d which are characterized by a sequence of time-locked pulses with slowly v
arying magnitude. We present numerical evidence and heuristic arguments, in
dicating that the dynamics of LFF's emerges as a result of quasiperiodic bi
furcations from these solutions as the pumping current increases. Regular p
eriodic solutions can actually be observed when (1) the feedback level is m
oderate, (2) pumping current is below solitary threshold, and (3) the linew
idth enhancement factor is relatively large.