Combined effect of chirping, group velocity dispersion and self phase modulation in a optical transmission system using different types of fiber

Abstract

The present epoch of communication is placing an extensive data transmission load on the optical networks and due to some impairments like group velocity dispersion (GVD), non-linearity and frequency chirping, leads to more signal distortion and limits the transmission distance significantly in high bit rate optical system. The chirp of an optical pulse is the time dependence of its instantaneous frequency and it can result from refractive index changes associated with changes in carrier density within the laser or during propagation due to effect of GVD and nonlinearities. In this research work, analytical and numerical analysis have been carried out to evaluate the transmission performance by solving the nonlinear Schrödinger equation considering GVD and chirped Gaussian pulse as input in terms of pulse broadening factor and also numerical analysis have been carried out for the above mentioned impairments. The results are evaluated at various data rates, different input powers as a function of transmission distance using standard single mode fiber (SSMF), large effective area fiber (LEAF), non-zero dispersion shifted fiber (NZDSF), multi-clad dispersion flattened fiber (MCDFF) and multi-clad dispersion shifted fiber (MCDSF). The performance evaluations are also presented in 3D environment for all 5 types of fiber. Results show that MCDSF gives better performance than SSMF, LEAF, NZDSF or MCDFF for same bit rate, power, link length and chirping factor. The results and observations of this research work will be helpful to design high bit rate long haul optical transmission system in an intensity modulated and direct detection fiber-optic system.