Add-Drop Demultiplexer Operating in an Optical Michelson Interferometer Based in Fiber Bragg Gratings for Time Division Multiple Access Systems

Abstract

This article presents a numerical investigation of the propagation and switching of ultra-short pulses ( 2 ps) using a fiber-optic Michelson interferometer. In this study, the performance of the Michelson interferometer is studied as a function of the non-linear characteristics of the coupler and the fiber Bragg gratings. The numerical studies were done starting from the coupled-mode equations solved using the fourth-order Runge-Kutta method. The switching characteristic of the short pulses was examined as a function of pump power and the dephasing in the reflection amplitude of one of the Bragg gratings in order to obtain an add-drop filter operation. Transmission characteristics, such as cross-talk level, extinction ratio coefficient, and compression factor, were analyzed for different dephasing values and pump powers. Pump powers were examined from below the critical power of the coupler of switching (P D 1 W), at the critical power of switching (P c D 1:73 W), and above (P D 1:95 W). Through this study, one can verify that the transmission, cross-talk level, extinction coefficient, and compression factor depend on the pump power inserted into the device and in the dephasing. The optical fiber Michelson interferometers with identical gratings in the two output arms implement important components as a demultiplexer in add-drop devices. This device has attracted great interest in the field of all-optical switching in telecommunications for operating with high transmission rates.