The applications of high-power diode laser arrays are increasingly demanded in the consumer, medical and defense sectors. Careful attention must be given to the thermal control of these semiconductor devices. Each diode emits a modest amount of heat over the microscopic footprint of the device, which drives the heat flux density to extreme values on the order of kW/cm2. Current liquid heat exchangers are inefficient and will soon reach their limits for removing the heat as the optical power of diode lasers increase. Spray cooling offers an attractive thermal management solution for laser diodes. Spray cooling will also improve operating efficiency through precise temperature control.