Rodrigo Acuna Herrera

Influence of acoustic waves on supercontinuum generation in photonic crystal fibers

In this work, the influence of applying acoustic frequencies to photonic crystal fibers (PCF) on the supercontinuum (SC) generation is presented. We will show numerically the strong influence of coupling modes in PCF in the latest stage of SC and simulations of different scenarios of phase math condition between the modes.In this work, the influence of applying acoustic frequencies to photonic crystal fibers (PCF) on the supercontinuum (SC) generation is presented. We will show numerically the strong influence of coupling modes in PCF in the latest stage of SC and simulations of different scenarios of phase math condition between the modes.

Modeling Nonlinear Acoustooptic Coupling in Fiber Optics Based on Refractive Index Variation due to Local Bending

A detailed procedure is presented to compute analytically the acoustooptic coupling coefficient between copropagating core and lowest-order cladding modes in tapered fiber optics. Based on the effect of the local bending, the linear and nonlinear variations in the refractive index are modeled. A set of equations and parameters are presented in order to calculate the influence of acoustooptic effect in nonlinear pulse propagation. We will show that as the tapered fiber diameter decreases more energy can be transferred to the cladding and the nonlinear phenomena can compensate the coupling coefficients effects.

Nonlinear pulse propagation in wavelength dependence of birefringence fiber optics

We perform an analytical and numerical analysis of the influence of wavelength dependence of birefringence (WDB) during nonlinear pulse propagation through fiber optics. We find a set of coupled nonlinear equations, which allows for the study of the WDB in fibers. For the first time, to the best of our knowledge, the concept of cross-dispersion birefringence (CDB) is introduced to show what makes spectral pulse evolution broaden faster than usual. Some linear and nonlinear phenomena are analyzed, such as polarization trajectories, four-wave mixing, and supercontinuum (SC) generation. We show that the WDB changes the polarization states dramatically and Stokes and anti-Stokes waves linearly move toward longer and shorter wavelengths, respectively. Finally, we demonstrate that CDB has the capability to generate SC with immunity to the initial polarization angle.

Dispersive wave frequency in birefringent fiber optics

Abstract. We show an analytical and numerical study of dispersive wave (DW) frequency generated by solitons in birefringent fiber optics. We propose some analytical approximations for finding the DW frequency that agrees with numerical results for small normalized third-order dispersion. We also show that a scalar DW frequency equation is not valid for all birefringent optical fiber cases.

Dispersive waves in birefringent nonlinear fiber optics

Abstract. We perform theoretical analysis of dispersive waves generated by soliton in birefringent photonic crystal fibers. With Lagrangian formulation and Stokes parameters, we study the state of polarization of solitons under various levels of birefringence and third order dispersion. Then we investigate numerically the variation of dispersive wave frequency for different initial polarization angles and further consider the effect of stimulated Raman scattering.

Experimental study of Kerr effect and nonlinear absorption of multi walled carbon nanotubes

In this research, the influence of pulse width and energy on the nonlinear refractive index (n2) and nonlinear absorption (β) in Multiwalled carbonnanotubes (MWCNTs) were experimentally studied. For this purpose, three different MWCNTs concentrations were used and were dispersed in a Polyvinyl alcohol (PVA) solution. We found a highly dependence of n2 and β with the MWCNTs concentration, optical intensity, and pulse width.In this research, the influence of pulse width and energy on the nonlinear refractive index (n2) and nonlinear absorption (β) in Multiwalled carbon- nanotubes (MWCNTs) were experimentally studied. For this purpose, three different MWCNTs concentrations were used and were dispersed in a Polyvinyl alcohol (PVA) solution. We found a highly dependence of n2 and β with the MWCNTs concentration, optical intensity, and pulse width.

Analysis of Spatially Doped Fused Silica Fiber Optic by Means of a Hamiltonian Formulation of the Helmholtz Equation

This paper discusses an alternative method for calculating modal parameters in optical fibers such as propagation constants, transverse distributions, and anisotropy, due to linear and nonlinear phenomena acting as perturbations caused by doped silica regions. This method is based on a Hamiltonian formulation of the Helmholtz equation and the stationary perturbation theory, which allows a full-vectorial description of the electric field components when linear anisotropic inhomogeneities and Kerr nonlinearity are included. Linear and nonlinear parameters can be found for each propagating mode, and its accuracy has been successfully tested when compared to numerical calculations from the vector finite element method, and the results are published in the literature. This method facilitates the calculation of the spatial-distributed perturbation effects on individual electric field components for each propagating mode.

Influence of the Wavelength Dependence of Birefringence in the Generation of Supercontinuum and Dispersive Wave in Fiber Optics

In this paper, we perform numerical analysis about the influence of the wavelength dependence of birefringence (WDB) in the Supercontinuum (SC) and dispersive wave (DW) generation. We study different birefringence profiles such as constant, linear, and parabolic. We see that, for a linear and parabolic profile, the generation of SC practically does not change, while this does so when the constant value of the birefringence varies. Similar situation happens with the generation of dispersive waves. In addition, we observe that the broadband of the SC increases when the Stimulated Raman Scattering (SRS) is neglected for all WDB profiles.

Nonlinear Acousto-Optic Coupling in Tapered Fiber Optics: Model and Experiment

In this letter, a complete model and experimental verification of the nonlinear acousto-optic coupling between a co-propagating core and lowest-order cladding modes in tapered fiber optics are presented. The methodology presented in previous works have been extended to construct a full model, based on the local bending effect to compute the linear and nonlinear variations in the refractive index, which explains the influence of the acousto-optic effect in nonlinear pulse propagation. We show that there is good agreement between the results of the model and experiment.

Generation of optical super-Gaussian pulses using tapered fibers

Using a model for the shape of tapered fiber optics, we numerically study the effect of the taper shape profile on nonlinear optical pulse propagation. We show that super-Gaussian pulses can be generated and controlled and they are independent of higher-order nonlinearities, which makes them a good candidate for optical communications. We see that it is possible to compensate for the z variation of the dispersion with the nonlinear parameter and obtain the solutions of the homogeneous nonlinear Schroedinger equation.