2 research outputs found
Helical vs. fundamental solitons in optical fibers
We consider solitons in a nonlinear optical fiber with a single polarization
in a region of parameters where it carries exactly two distinct modes, the
fundamental one and the first-order helical mode. From the viewpoint of
applications to dense-WDM communication systems, this opens way to double the
number of channels carried by the fiber. Aside from that, experimental
observation of helical (spinning) solitons and collisions between them and with
fundamental solitons are issues of fundamental interest. We introduce a system
of coupled nonlinear Schroedinger equations for fundamental and helical modes,
which have nonstandard values of the cross-phase-modulation coupling constants,
and investigate, analytically and numerically, results of "complete" and
"incomplete" collisions between solitons carried by the two modes. We conclude
that the collision-induced crosstalk is partly attenuated in comparison with
the usual WDM system, which sometimes may be crucially important, preventing
merger of the colliding solitons into a breather. The interaction between the
two modes is found to be additionally strongly suppressed in comparison with
that in the WDM system in the case when a dispersion-shifted or
dispersion-compensated fiber is used.Comment: a plain latex file with the text and two ps files with figures.
Physica Scripta, in pres
Suppression and Enhancement of Soliton Switching During Interaction in Periodically Twisted Birefringent Fiber
Soliton interaction in periodically twisted birefringent optical fibers has
been analysed analytically with refernce to soliton switching. For this purpose
we construct the exact general two-soliton solution of the associated coupled
system and investigate its asymptotic behaviour. Using the results of our
analytical approach we point out that the interaction can be used as a switch
to suppress or to enhance soliton switching dynamics, if one injects
multi-soliton as an input pulse in the periodically twisted birefringent fiber.Comment: 10 pages, 4 figures, Latex, submitted to Phys. Rev.