Abstract

The switching dynamics of short optical pulses in a directional coupler made of two single-mode fibers (or waveguides), which is assumed to possess uniform Kerr nonlinearity, is investigated theoretically. When the nonlinearity is weak, the function of the coupler can be described by the beating between the symmetric and the antisymmetric modes of the composite waveguide structure. The group-delay difference between these two modes (intermodal dispersion) can give rise to pulse broadening or even pulse breakup. New normal-mode equations and coupled-mode equations that include the effect of intermodal dispersion are derived and discussed. The intermodal dispersion in the normal-mode formulation is found to be equivalent to the coupling-coefficient dispersion in the coupled-mode formulation. In many practical cases the intermodal dispersion is much more significant than the group-velocity dispersion, and soliton pulses are switched in the same way as any low-power linear pulses. Only in the special case that the intermodal dispersion is negligible, compared with the group-velocity dispersion, do the new coupled-mode equations reduce to the well-known linearly coupled nonlinear Schrödinger equations. A normalized parameter is proposed to determine the relative importance of the two dispersion effects.

© 1997 Optical Society of America

Full Article  |  PDF Article

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (1)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (1)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (46)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription