Controlling diode laser bar temperature by micro channel liquid cooling

In this paper investigations of temperature control of micro channel cooled high power diode lasers are presented. After a short motivation the theoretical background of a complete liquid cooling system is introduced and the simulation results are compared to the behavior of a real-world system. Because of the nonlinear dependence of the thermal resistance on the water flux modern control algorithms are required to achieve a sufficient control quality and robustness. Their design and characterization are presented as well. Based on the results of diode laser temperature control the potentials to realize a highly efficient wavelength control are discussed. To support future system integration and to realize the controller with minimal hardware expenditure an application specific integrated circuit (ASIC) was developed.