Thermal effect analysis of laser rod by diode laser end-pumped

In order to solve the thermal effect problem of laser rod by diode laser end-pumped, based on the heat conduct theory, a novel eigenfunction group of heat conduction equation was established and the general solutions of temperature field and thermal distortion field within laser rod were obtained. These analytical solutions not only solve the problem of calculation error in temperature field brought by the approximate assumption of radial heat flow in laser rod, but also overcome the problem of low precision caused by the numerical analysis method. The results show that when the output power of diode laser is 20 W, and the Gaussian spot radius is 200 μm, 0.5% (mass fraction) Nd-ion doped yttrium vanadate laser rod can get a maximum temperature rise of 451.2°C and a maximum thermal distortion of 3.42 μm. The distribution of heat flow in laser rod is not radial through analyzing of the isotherm diagram. Compared to the calculation results with the assumption of radial heat flow in laser rod, the maximum temperature rise is reduced by 30%. The results can be applied to the design of resonant cavity and offer theoretical basis for reducing the thermal effect in laser system.