Periodic Modulation of Nonlinearity in a Fiber Bragg Grating: A Numerical Investigation

Antonio Francisco Gomes Furtado Filho, José Rubens Rodrigues de Sousa, Apiano Ferreira de Morais Neto, Jose Wally Mendonça Menezes, Antonio Sergio Bezerra Sombra

Department of Infrastructure, Telecommunications Systems Specialist Laboratory and Teaching, East, Federal Institute of Ceará, Fortaleza Campus, Fortaleza, Brazil..
Telecommunications and Materials Science and Engineering Laboratory (LOCEM), Campus do Pici, Fortaleza-CE, Brazil.
Teleinformatics Engineering Department, Federal University of Ceará, Fortaleza-Ce, Brazil.

DOI: 10.4236/jemaa.2012.42007                

Abstract

We present numerical studies on the switching characteristics of a fiber Bragg grating (FBG) with modulation in the third order nonlinear index of refraction along it’s length. The FBG is operating in a continuous wave regime (CW). This study was done taking into account the possible asymmetry brought by the non harmonic modulation of the nonlinearity, leading to different reflection and transmission characteristics, that depend on the direction of propagation along the modulated nonlinear FBG. This phenomenon may be useful for applications like an optical isolator. It was found that for a set of values of the modulation parameter, the FBG can exhibit multistable states. The numerical studies were obtained starting from the coupled-mode equations solved from the coupled-mode theory and simulated using the fourth-order Runge-Kutta method.

Keywords

Bragg Gratings; Nonlinearity Modulation; Optical Bistability; Nonlinear Switching

Conflicts of Interest

The authors declare no conflicts of interest.

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