Simulation of Chirped Pulse Propagation in Silicon Nanowires: Shape and Spectrum Analysis

Abstract

In this paper, we simulate the propagation of chirped pulses in silicon nanowires by solving the nonlinear Schrödinger equation (NLSE) using the split-step Fourier (SSF) method. The simulations are performed both for the pulse shape (time domain) and for the pulse spectrum (frequency domain), and various linear and nonlinear effects changing the shape and the spectrum of the pulse are analyzed. Owing to the high nonlinear coefficient and a very small effective-mode area, the required length for observing nonlinear effects in nanowires is much shorter than that of conventional optical fibers. The impacts of loss, nonlinear effects, second-and third-order dispersion coefficients and the chirp parameter on pulse propagation along the nanowire are investigated. The results show that the sign and the value of the chirp parameter have important role in pulse propagation so that in the anomalous dispersion regime, the compression occurs for the upchirped pulses, whereas the broadening takes place for the down-chirped pulses. The opposite situation happens for up-and down-chirped pulses propagating in the normal dispersion regime.

Interactive tool for learning propagation in single‐mode optical fibers in telecommunication engineering

“…When ISI appears, the transmission capacity can be highly affected and thus, it may reduce the BL product dramatically. In addition, in many practical applications of optical communications today, pulses are generated by direct modulation of semiconductor lasers because it is a simple and low‐cost process where no intermediary elements are needed between the laser light and the modulator …”

“…In addition, in many practical applications of optical communications today, pulses are generated by direct modulation of semiconductor lasers because it is a simple and low-cost process where no intermediary elements are needed between the laser light and the modulator. [7,8] The direct modulation of pulses generally introduces chirp or frequency redistribution effects before their propagation, which usually worsen the effects of chromatic dispersion in the single-mode fiber. Nevertheless, through correct joint modeling or selection of both fiber and light source, the direct modulation can counteract the chromatic dispersion's effects and serve as a tool to reduce ISI or equivalently, increase the BL product.…”