M. Facão

Propagation of Airy-related beams

New types of finite energy Airy beams are proposed. We consider two different types of beams, namely, beams that are obtained as blocked and exponentially attenuated versions of Airy functions Ai and Bi, and beams of finite width but having the Airy functions typical phase. All of them show very interesting properties, such as parabolic trajectories for longer propagation distances, profile evolution exhibiting less diffraction, or better definiteness of the main peak, when compared with other finite energy Airy beams studied before.

Stable soliton propagation in a system with spectral filtering and nonlinear gain

Stable soliton propagation in a system with linear and nonlinear gain and spectral filtering is investigated. Different types of exact analytical solutions of the cubic and the quintic complex Ginzburg-Landau equation (CGLE) are reviewed. The conditions to achieve stable soliton propagation are analyzed within the domain of validity of soliton perturbation theory. We derive an analytical expression defining the region in the parameter space where stable pulselike solutions exist, which agrees with the numerical results obtained by other authors. An analytical expression for the soliton amplitude corresponding to the quintic CGLE is also obtained. We show that the minimum value of this amplitude depends only on the ratio between the linear gain and the quintic gain saturating term.Stable soliton propagation in a system with linear and nonlinear gain and spectral filtering is investigated. Different types of exact analytical solutions of the cubic and the quintic complex Ginzburg-Landau equation (CGLE) are reviewed. The conditions to achieve stable soliton propagation are analyzed within the domain of validity of soliton perturbation theory. We derive an analytical expression defining the region in the parameter space where stable pulselike solutions exist, which agrees with the numerical results obtained by other authors. An analytical expression for the soliton amplitude corresponding to the quintic CGLE is also obtained. We show that the minimum value of this amplitude depends only on the ratio between the linear gain and the quintic gain saturating term.

Optical Solitons in Fibers for Communication Systems

Abstract A brief history of attempts to use solitons for optical fiber communications and of the technical developments toward making soliton transmission practical is reviewed. The main problems affecting long-distance soliton transmission, as well as techniques to solve them, are described. Recent developments concerning the use of dispersion management and some of the remarkable properties of dispersion managed solitons are also discussed.

Evaluation of the fuse effect propagation in networks infrastructures with different types of fibers

The evaluation of the fuse effect propagation in fiber networks is analyzed. We show a relation between the void interval, the power density and the fused effect velocity for different types of optical fibers.

Threshold power of fiber fuse effect for different types of optical fiber

In this work we measured the threshold power level for the fiber fuse effect ignition and propagation for different types of optical fibers. We verified that the threshold power is not proportional to the fiber mode field diameter.

Simulation of fiber fuse effect propagation

In this work, we present the simulation results of the fiber fuse effect propagation, using a one-space-dimensional model. This approach has the advantage of reducing the simulation time. The obtained simulated results are in agreement the experimental ones.

Analysis of power transfer on multicore fibers with long-period gratings.

The use of long-period gratings (LPGs) to distribute optical power from one core to all the cores in a multicore fiber (MCF) is theoretically analyzed. Simple analytical expressions that describe the mode powers evolution along the LPGs are derived from the coupled mode equations. This study demonstrated the power transfer between cores in a MCF promoted by identical LPGs. Moreover, with this technique, the pump signal can be distributed to all the cores without interfering with the transmission signals.

Analysis of Timing Jitter for Ultrashort Soliton Communication Systems Using Perturbation Methods

Abstract We analyse timing jitter of ultrashort soliton systems taking into account the major higher order effects, namely, intrapulse Raman scattering and third order dispersion and using adiabatic perturbation theory. We obtain an expression for the soliton arrival time variance that depends on the quintic power of propagation distance. This timing jitter could be partly overcome by use of bandwidth-limited amplification as it happens in systems using longer solitons. In this case the quintic dependence with distance is reduced to a linear one.

Effect of bending in SMF fibers under high power

In this work we investigate the coating damages in optical fibers under the simultaneous effects of high optical power and tight bending. The power losses and coating heating imposed by the high power propagation have been measured for a SMF fiber. We have implemented a theoretical thermal model for the fiber bend and the minimum safety bend diameter has been established.

Optical fiber bending limits for optical fiber infraestructures

In this work the high power propagation in tight bent fibers was studied. The signal losses and the temperature increase have been experimental measured for single mode optical fibers (SMF) as function of the bending diameter. These results were used to propose an approach to limit the bending diameter, as a function of the injected power, in order to maintain the operational condition bellow the safety limit.