Experimental study on cooling of high-power laser diode arrays using hybrid microchannel and slot jet array heat sink

In this study, a hybrid microchannel and slot jet array heat sink is designed and fabricated to achieve a better thermal performance of the high-power laser diode arrays. A standard commercial laser bar with wavelength of 808 nm is packaged on the heat sink and experiments are performed to assess the cooling performance of the hybrid heat sink. In the experiments, the forward voltage method is used to measure the chip temperature and the structure function method is applied to obtain the thermal resistance of the heat sink. Using the deionized water as coolant, the heat sink deals with a heat flux of up to 506 W/cm² and the thermal resistance of the heat sink is only 0.23 K/W when the flow rate is 0.8 L/min (The average jet velocity is 13.3 m/s). The optical power can be up to 135.5 W corresponding to the wall plug efficiency of 64.2%. Compared with the published solutions related to cooling similar laser chips, the thermal resistance reduces by over 15%, indicating that this hybrid heat sink is an interesting solution to improve the cooling of the high-power laser diode arrays.