Pulse Propagation In Multimode Fibers Research Articles

Dynamics of femtosecond supercontinuum generation in multimode fibers

We solve a system of generalized nonlinear Schrödinger equations to study the nonlinear dynamics of ultrashort pulse propagation in multimode fibers. Due to pulse walk-off, permanent intermodal power transfer between modes is observed even in absence of phase matching. The strength of intermodal effects is found to depend strongly on modal symmetries, which results in preferential coupling between the LP(0n) modes. The scaling of nonlinear multimode effects in large-core fibers for the generation of ultra-high power spectral density supercontinua is finally discussed.

Distributed loss and mode coupling and their effect on time-dependent propagation in multimode fibers

A first-order solution to the transport equation for the total power propagating in each degenerate mode group of a multimode fiber is used to describe pulse propagation in multimode fibers. The basic transport equation is supplemented by models for Rayleigh-scattering-induced losses, mode coupling, and the modal group velocity function. Each of these models can be specified for a particular fiber from a standard set of near-field measurements and then incorporated into pulse propagation simulations, which closely matched the measured pulse response of test fibers.

Optical interference and pulse propagation in multimode fibers

Abstract The role played by optical interference in determining the propagation of pulses in multimode fibers is examined under conditions of mode independence and mode coupling. Single pulses and pulse-pairs generated by a source that has arbitrary temporal and spatial coherence are considered, and the role played by the spatial integration at the detector, which effectively is a form of spatial incoherence, is investigated. It is shown that three forms of optical interference may result under different conditions of source spatiotemporal coherence—intramodal, intermodal, and interpulse interference. These effects change the profile of received pulses in a, in general, nonlinear way.

Pulse Propagation in Multimode Fibers with Frequency-Dependent Coupling

Marcuse's time-dependent coupled power equations are rederived so as to include the frequency dependence of the coupling coefficients. For the case of white-noise coupling, the solution is then expressed simply in terms of that for frequency-independent coupling