Finite-Element Thermal Simulation of High-Power Diode Laser Stacks for High-Duty-Cycle Pump Applications

The two-dimensional heat distribution (steady-state and transient) within high-power diode laser stacks is simulated using a newly-developed model, based on finite element analysis and calibrated against prior experimental results. The model is then used to estimate the average temperature and thermal impedance of the stack elements under quasi-continuous-wave pulsed operation and investigate the impact of variations to the pulse conditions (pulse width and duty cycle). It is also used to show how using improved heat-spreading materials and increasing cooling efficiency can significantly reduce thermal impedance, thereby enabling duty cycle and optical power scaling.