Technology Research, Based On Dispersion Decreasing Fiber Optical Pulse Compression

In this dissertation, relevant theories of conventional optical fiber are introduced first. A basic equation which governs propagation of optical pulse in single-fibers is obtained on the basis of the Maxwell's Equations, and analyses are conducted over the factors and circumstances of optical pulse propagation in optical fiber. One way to solve the basic equation is the split-step Fourier Method, so we explain this method in detail.The methods and principles of pulse compression based on dispersion-decreasing fiber are described, its progress is reviewed.The newly method of ultra-short soliton generation through higher-order soliton compression in a nonlinear optical loop mirror constructed from dispersion-decreasing fiber is researched. First, we discuss this situation in which fundamental soliton is generated from the compression of the 6 order soliton. Then we study the influence of the input pulse shape, the initial frequency chirp, and the high order effects on the pulse compression. We find that the output pulse is insensitive to these factors. We also study the performance of fiber loop mirror constructed from GVD step-decreasing fiber and show that this device performs very well.Finally, A Mach-Zehnder interferometer constructed from dispersion-decreasing fiber is proposed for simultaneous compression and pedestal suppression of highe-order soliton. Numerical simulation indicates that it permits efficient pulse compression and easy choice of the DDF length. When proper coupler ratio is chosen, output pulse with little pedestal and high compression can be generated. Results show that high quality pulse can also be generated when the input to output dispersion ratio of DDF is larger. The results also show that the compression of optical pulse in a Mach-Zehnder interferometer constructed from logarithmic dispersion profile is optimal.