Multistage thermoelectric micro coolers

Multistage thermoelectric coolers have been used for a long time because they offer a larger temperature difference than single stage thermoelectric coolers. MEMS technology leads to the possibility to fabricate multistage thermoelectric micro coolers in batches without much increase in complexity compared to single stage cooler fabrication. In this paper, we discuss the design of multistage thermoelectric coolers to optimize the maximum temperature difference, which is of particular interest for micro coolers. As an example, a two-stage thermoelectric micro cooler is designed for the thermal management of a 10 mW mid-IR laser. The heat leakage issue, the most important degradation mechanism for the performance of thermoelectric micro coolers, is also discussed and possible solutions are also presented.