Effective single-mode model of laser cavity dynamics

This paper presents an effective single-mode model of laser cavity dynamics, focusing on pulsed lasers, which significantly improves the computational efficiency of state-of-the-art models while exhibiting a comparable model accuracy. The phenomenon of gain-narrowing is discussed starting from a spatially lumped model with a spectrum of multiple longitudinal modes. Based on this information, effective mode parameters are derived, which convert the multi-mode behavior to time-varying dynamics for the total intracavity power. A simulation study for a cavity-dumped Nd:YAG laser shows that the simple model agrees well with the original model. The results presented in this work can be utilized for laser optimization and controller design for a wide range of photonic systems where a compromise between model accuracy and complexity is desired.