Effects Of Intermodal Dispersion Research Articles

Study on chirped dark, bright solitons conversion and the effect of intermodal dispersion, self-frequency shift, and self-steepening effect on the chirping of bright, dark, and kink solitary waves

This study reveals the dynamics of short optical pulses in nonlinear media. Then, for the survival of different types of solitary waves in the nonlinear medium, the constraint relations to the physical parameters and chirps associated with each of the solitary waves are explicitly shown. We authenticate numerically all those obtained from the analytical method and show the chirping effect is saturative in nature and can be managed by changing coefficients of inter-modal dispersion, stimulated Raman scattering (SRS), and self-steepening effect. We also verify the more operative condition of intermodal dispersion.

Straddled optical solitons for Biswas-Arshed equation with intermodal dispersion

This paper studies the Biswas-Arshed equation that is considered with the effect of intermodal dispersion. Kudryashov’s integrability approach reveals the straddled solitons that emerge from this model. The simulations are also presented for a visual effect of the obtained solutions.

Soliton solutions of Kundu-Eckhaus equation in birefringent optical fiber with inter-modal dispersion

We study the dynamics of optical soliton in birefringent optical fiber with the effect of inter-modal dispersion. We consider the model of the Kundu-Eckhaus (KE) equation for birefringent optical fiber with the inclusion of inter-modal dispersion. Multisoliton solutions of KE equation with the presence of inter-modal dispersion are found analytically by using mapping method and a symbolic computation system. Initially, the solutions are expressed in terms of the Jacobi elliptic function which is also recovered by the use of limiting case of modulus of ellipticity. With the help of graphical illustrations of our solutions, we understand the effect of inter-modal dispersion on the soliton evolution in optical birefringent optical fiber.

Effects of intermodal dispersion and fiber length on the mode-locking of a dual-core fiber laser

We investigate theoretically how the intermodal dispersion and the fiber length influence the formation of ultrashort pulses in a dual-core fiber laser. Our simulation using the Ginzburg–Landau equation found that stable self-starting of mode-locking can be achieved with a fiber length deviating from integer multiples of the linear coupling length. Furthermore, the intermodal dispersion will not lead to pulse splitting, in contrast, it will induce asymmetry in the pulse shape and increase the modulation instability. Consequently, a filter is found necessary to stabilize the mode-locking operation when the fiber length is longer than the linear coupling length.

Effects of intermodal dispersion on short pulse propagation in multi-core fibers

The effects of intermodal dispersion on ultrashort optical pulse propagation through multi-core fibers are analyzed theoretically, which has been ignored in previous studies. A three-core fiber with collinear and triangular configuration and a four-core fiber are considered. We demonstrate with numerical examples that the intermodal dispersion can cause pulse breakup effect in multi-core fibers.

Radar distance measurements in circular waveguides involving intermodal dispersion effects

This contribution deals with guided radar distance measurements in the field of industrial tank level control. The aim is to achieve a submillimeter gauging accuracy even when conducting the measurement within a highly dispersive environment of large and thus overmoded circular waveguides. Normally, multimode propagation causes a decrease in measurement precision. Therefore, the effects of intermodal dispersion are fundamentally reviewed and, based on these results, a correlation-based signal processing method is presented. This method is able to exploit the otherwise parasitic dispersion effects to enhance the measurement precision even in constellation with a simple waveguide transition or antenna, respectively. Furthermore, considerations on the mode variety and its influence on the signal complexity as well as investigations on the technique's reliability and accuracy are presented. Measurement results in a frequency range of 8.5–10.5 GHz are provided for three different kinds of waveguide transitions proving the capability of the method.

A comparative study of soliton switching in a two- and three-core coupler with TOD and IMD

A numerical study of soliton switching in a two- and three-core coupler is carried out taking into account the effect of intermodal dispersion and third-order dispersion. A two and three-core coupler with linear and triangular configuration is considered. It is found that the three-core coupler with linear configuration shows the best switching characteristics.

Effects of Intermodal Dispersion on Short Pulse Propagation in an Active Nonlinear Two-Core Fiber Coupler

The effects of intermodal dispersion in a passive two-core fiber coupler have been investigated. In this letter, we extend the study from the passive to the active two-core fiber coupler and investigate the effects of intermodal dispersion on the performance of the active coupler. In particular, we observe a new feature caused by the interaction between the intermodal dispersion and the gain bandwidth: The pulse breakup effect due to intermodal dispersion can be suppressed by the finite bandwidth of the linear gain.

Exploiting diversity in multimode fiber communications links via multisegment detectors and equalization

we propose diversity combination via optical multisegment detectors and electrical equalization techniques to mitigate the effects of intermodal dispersion in multimode fiber (MMF). With no equalization in MMF links, intermodal dispersion produces intersymbol interference (ISI) in the received optical signal that severely limits the achievable data transmission rates and fiber link lengths. Our quasi-simulated performance results (obtained with measured impulse responses) demonstrate that multisegment detection and equalization provide a low-cost and efficient solution to combat ISI and hence, to enhance the performance of MMF communications links.

Effects of intermodal dispersion on two-nonidentical-core coupler with different radii

A pair of new generalized coupled-mode equations that describes the switching dynamics of optical pulses in two nonidentical parallel waveguides, with consideration of dispersive properties of the coupling coefficient, is presented. We have investigated the characteristics of intermodal dispersion between the two cores with different radius ratios and analyzed the effect of intermodal dispersion on the switching dynamics.

Soliton states in a nonlinear directional coupler with intermodal dispersion

We study numerically the propagation of short optical pulses in a nonlinear directional coupler that possesses significant intermodal dispersion. Using the split-step method with fast Fourier transform, we calculate the soliton solutions of such a coupler and highlight the effect of intermodal dispersion on the propagation dynamics of the pulses. We find that the intermodal dispersion has only a small effect on the shape of the soliton states, in spite of the fact that it can distort and break up low-energy pulses launched into one arm of the coupler. The intermodal dispersion, however, can cause a drift in the velocity of the soliton pulses.

Influence of intermodal dispersion on the switching of solitons at different wavelengths in twin-core fiber couplers

In dual-core fibers the variation of the coupling coefficient with frequency leads to intermodal dispersion that perturbs the switching of ultrashort pulses. Using a new version of the split-step Fourier method based on a model that includes intermodal dispersion, we show that this effect cannot be neglected when the switching of picosecond solitons at different wavelengths in half-beat twin-core fiber couplers is analyzed, although picosecond solitons at the central wavelength are not significantly affected. We also show that to study the switching of wavelength-division-multiplexed solitons one should always take into account the effect of intermodal dispersion.

All-optical pulse switching in twin-core fiber couplers with intermodal dispersion

Due to the dispersion mismatch between the two supermodes of a two-channel coupler, pulse switching cannot be analyzed without taking into account the effect of intermodal dispersion. Using full numerical simulations, we show the influence of intermodal dispersion on all-optical switching with ultrashort pulses in twin-core fiber couplers. For the nonlinear regime, however, only subpicosecond and femtosecond pulses are affected in the cross state since the parallel state remains almost unaffected.

Propagation of short optical pulses in directional couplers with Kerr nonlinearity

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.