An Efficient Approach for Time-Domain Simulation of Pulse Propagation in Optical Fiber

A novel approach is proposed for split-step time-domain simulation of pulse propagation in optical fiber. In this approach, a Fourier series expansion method is introduced for time-domain digital filter extraction from any given fiber transfer function. With such extracted filter coefficients and a double Tukey window function, the filter length can be optimized for a given error tolerance. This method is validated by comparing our simulation results with that obtained from the well-known split-step frequency-domain method. Through several simulation examples, we find that this solution technique is much more efficient than other existing time-domain approaches-as much as 92% of the computation time can be saved. It even outperforms the well-known split-step frequency-domain fast Fourier transform method in terms of the computation efficiency, under the condition that the input signal samples are huge-a situation we often meet in dealing with wavelength division multiplexing systems. Moreover, we find that the truncation effect at the computation window edge introduced by the time-domain algorithm is less severe than the aliasing effect associated with the frequency-domain method, not to mention that we can eliminate the truncation error by using a sliding window, only at a small cost on computation time.