Estimation of maximum output power of double clad fiber laser

Temperature distribution in high power fiber laser was approximately analyzed by thermal conductive equation and boundary condition.The rationality of numerical solution was validated by ANSYS simulation.The fiber laser coating’s critical temperature was set 80 ℃ and the maximum output power using the thermal conductive equation was computed when the fiber laser is cooled by fan or water, such as Ybdoped double clad fiber laser. Results indicate that when the fiber is cooled in air (the heat transfer coefficient is 10 W·m－２·K－１), fiber lasers maximum output power is 105 W. When the fiber is cooled by fan (the heat transfer coefficient is 80 W·m－２·K－１), the maximum output power is 820 W. If the output power is demanded above 1 kW, the fiber laser must be cooled by water．