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.