Unified model for spectral and temporal properties of quasi-CW fiber lasers

This paper discusses a unified theoretical approach to model the spectral and temporal properties of various quasi-continuous-wave (quasi-CW) fiber lasers. The unified spectral evolution model and temporal evolution model of quasi-CW fiber lasers are established by demonstrating the nonlinear propagation equations with gain coefficient and analyzing the corresponding definite conditions and computation methods for effective simulations. Simulation results based on the two unified models are given to show their capacities and application scope in describing the basic spectral and temporal properties of typical quasi-CW fiber lasers involving single gain mechanism with a simple structure. Furthermore, the two unified models could also be extended to analyze the spectral and temporal properties of quasi-CW fiber lasers involving a hybrid gain mechanism or with a composite structure. Overall, the unified spectral evolution model and temporal evolution model could provide a useful tool to describe and design quasi-CW fiber lasers and quasi-CW fiber amplifiers.