Various pumping modes of high-power double clad fiber laser

Abstract

As one of the first invented laser categories, fiber laser plays a crucial role in many specific fields, e.g., filed-optic communication, sensing, industrial processing, national defense, military. In order to effectively couple the pump light into the single-mode fiber, double-clad fiber laser was invented, i.e., the power and efficiency of fiber lasers have been significantly improved. There are two mainly categories of pumping mode for double clad fiber laser, named as end smoothing the gain curve pumping and side pumping. This paper will focus on the analysis and comparison of these two pumping modes in terms of the power, efficiency, relative population density, thermal load and feasibility. The experimental procedure will be achieved based on the MATLABR2021b and SFTool. The aim of the paper is to investigate the effects on the forward pumping and backward pumping in the process of side pumping and end pumping. According to the analysis, side pumping and bi-direction pumping smooth the gain curve effectively. Choosing appropriate pumping mode can reduce the loss and save the cost of optical transmission to a large extent. These results shed light on selection of pumping mode for high power fiber laser.