Calculating Optical Fiber Laser Output Pulse Spectra Using the Split-Step Fourier Method

This document presents the implementation of calculating optical fiber laser output pulse spectra using the split-step Fourier method. This numerical technique proves highly effective for analyzing laser performance characteristics through spectral decomposition. The algorithm operates by dividing the propagation problem into linear and nonlinear parts, alternately solving them in frequency and time domains using Fast Fourier Transform (FFT) operations. By applying Fourier transform principles, complex pulse signals are decomposed into spectral components, enabling detailed examination of optical fiber laser spectral properties. The implementation typically involves iterative propagation steps where dispersion effects are handled in the frequency domain while nonlinear effects are computed in the time domain. This approach is crucial for fiber laser design and optimization since spectral characteristics directly impact performance across various applications. Through the split-step Fourier method implementation with proper step-size control and boundary handling, we obtain comprehensive information about output pulse spectra, facilitating better understanding and improvement of fiber laser performance parameters.