Radiative losses due to pulse interactions in birefringent nonlinear optical fibers

Area of Science:

• Nonlinear optics
• Optical fiber communications
• Soliton dynamics

Background:

• Birefringent optical fibers support the propagation of two distinct polarization states.
• Nonlinear effects, such as self-phase modulation and cross-phase modulation, significantly influence pulse evolution.
• Coupled nonlinear Schrödinger (NLS) equations are the standard model for describing such phenomena.

Purpose of the Study:

• To investigate the transient evolution of two-polarization pulses in a birefringent nonlinear optical fiber.
• To develop an analytical approach using a trial function and Lagrangian formulation.
• To assess the impact of radiative shelf terms on the accuracy of the model.

Main Methods:

• Utilized a trial function approach incorporating coupled solitonlike pulses and a radiative shelf.
• Employed the Lagrangian formulation to derive ordinary differential equations (ODEs) for pulse parameters.
• Compared the analytical results with full numerical solutions of the coupled NLS equations.

Main Results:

• The trial function method successfully describes the transient evolution of two-polarization pulses.
• Inclusion of mass and momentum fluxes from the radiative shelf is essential for accurate modeling.
• The analytical approach with radiative fluxes shows good agreement with numerical simulations.

Conclusions:

• The proposed Lagrangian formulation with a radiative shelf provides an effective analytical tool for studying nonlinear pulse dynamics.
• Accurate modeling of transient pulse evolution in birefringent fibers necessitates accounting for radiative effects.
• This method offers a computationally efficient alternative to full numerical solutions for certain parameter regimes.