Abstract

The propagation and switching of short pulses in an active two-core fiber nonlinear directional coupler have been investigated theoretically by using the split-step Fourier method. The analysis highlights the effects of the second-order coupling coefficient dispersion, the linear gain coefficient, and the finite-gain bandwidth on the switching and propagation of short pulses. The research indicates that the linear gain can sharpen the switching characteristic and reduce considerably the switching threshold power, as well as significantly increase the switching efficiency with the influences of the second-order coupling coefficient dispersion. However, both the second-order coupling coefficient dispersion and the finite-gain bandwidth degrade the switching characteristics. In addition, the finite-gain bandwidth of linear gain not only suppresses significantly the pulse compression and amplification caused by the linear gain coefficient, but also suppresses effectively the frequent pulse fluctuation on pulse propagation induced by the second-order coupling coefficient dispersion; consequently, as in the case of the passive fiber coupler, optical pulses tend to restore periodical coupling propagation in active two-core fiber coupler.

© 2009 US

Generalized coupled nonlinear equations for the analysis of asymmetric two-core fiber coupler

M. Liu and P. Shum
Opt. Express 11(2) 116-119 (2003)

Coupling instability and power-induced switching with two-core dual-polarizations fiber nonlinear couplers

S. Trillo and S. Wabnitz
J. Opt. Soc. Am. B 5(2) 483-491 (1988)

Propagation of short optical pulses in directional couplers with Kerr nonlinearity

Kin Seng Chiang
J. Opt. Soc. Am. B 14(6) 1437-1443 (1997)

Finite-dimensional description of nonlinear pulse propagation in optical-fiber couplers with applications to soliton switching

E. Caglioti, S. Trillo, S. Wabnitz, B. Crosignani, and P. Di Porto
J. Opt. Soc. Am. B 7(3) 374-385 (1990)

Soliton switching in an erbium-doped nonlinear fiber coupler

James Wilson, G. I. Stegeman, and E. M. Wright
Opt. Lett. 16(21) 1653-1655 (1991)