Three-dimensional simulation of the temperature field in high-power double-clad fiber laser

The 3D temperature distribution in high-power double-clad fiber laser (DCFL) and the evolution of the temperature field in the fiber are analyzed, according to the transient heat conduction equation. The temperature in the fiber reaches the maximum after opening the pump light about 20 s, and cools down to the room temperature after shutting down for also about 20 s. The shape of the inner-clad can only affect the spacial distribution of the temperature outside of the core, but have no effect on the maximum temperature in the core.