Abstract
Vertical-cavity surface-emitting lasers (VCSELs) have generated extensive enthusiasm in scientific research on and applications of lasers. However, thermal resistance has seriously limited the performance of such devices for a long time, especially in high-power single-chip large-area VCSEL array modules. In this study, in order to determine the packaging thermal resistance bottleneck of the high-power VCSEL array laser module and achieve better performance, the thermal characteristics of an 808 nm VCSEL module were analyzed quickly with electrical transient measurements without any damage, which consisted of a 6 mm × 6 mm, 85 W, AlGaAs/GaAs VCSEL array chip encapsulated on a submount and a water-cooled heat sink. The quantitative components of the device's thermal resistance were clearly segmented and rapidly obtained within merely 25 s using the structure function algorithm. The packaging thermal resistances together accounted for an astonishing 70% of the total thermal resistance when the loading current was 8 A. Among them, R(submount) and R(solder2) were the main focus areas, which accounted for 54% of the total thermal resistance. We also applied the spectroscopy method to calculate the total thermal resistance of the module on a large scale from another perspective for the comparative verification of the electrical transient method. The values obtained by the two methods were relatively close. More importantly, this research will have a positive impact and an indicative effect on reducing the main thermal resistances of the VCSEL array module.