Performance Analysis Of Nonlinear Directional Coupler In Presence Of Random Dispersion

Abstract

ABSTRACT The importance of fiber optic communication is increasing at very fast pace in today’s world. The demand for transmission in broadband internet services for data transmission like real time video conferencing and in telecommunication network over the globe is growing at an exponential rate and only fiber optics communication networks are able to meet this challenge. Optical fiber communication systems are being extensively used all over the world for telecommunication, video and data transmission purposes. This is because of the huge capacity of optical fiber .It can provide data rates in Tbps over optical fiber by wavelength division multiplexing techniques. Switching function is very important in information processing in optical networks. The recent trend is to design All optical network elements in optical signal processing which eliminate use of costly high speed electronics because they don’t need optical to-electronic-to-optical' conversion. In our thesis work, we investigated Nonlinear Fiber Directional Coupler which has technological applications in power splitting, wavelength division multiplexing, demultiplexing, polarization splitting, and fiber optic sensing. We analyzed the Soliton switching characteristics of nonlinear directional fiber coupler in presence of Kerr nonlinearity and fifth order nonlinearity. The soliton pulse is used because it gives more efficient switching characteristics and also in future we have commercial optical soliton communication systems. The detrimental effect of quintic nonlinearity on switching dynamics of NLDC has been investigated. We also analyzed the switching characteristics in presence of third order dispersion in addition to group velocity dispersion. In practical optical systems, random dispersion can occur due to variation in core cladding diameter or fluctuations in carrier doping density and other factors like thermal stress. The random dispersion becomes important as quality of transmission increases. We investigated the switching characteristics of nonlinear fiber directional coupler in presence of random dispersion in real time conditions. To analyze it in more practical scenario, we considered the effects of Intrapulse Raman scattering, self steepening, third order dispersion, Intermodal dispersion along with Kerr nonlinearity and Quintic nonlinearity. We analyzed the switching dynamics by varying random dispersion in our system from 5 percent to 30 percent. The evolution of soliton pulse and respective contour plots are also studied. We found the tolerance limit in random dispersion with which NLDC gives faithful switching characteristics which would be helpful to designer of Fiber Couplers.