Performance analysis and improvement of microbolometer imaging system

Abstract

Microbolometer focal plane array (FPA), as a popular kind of uncooled infrared detector, has a wide range of low cost thermal imaging applications due to its high sensitivity and simple micro-fabrication process. The performance of microbolometer imaging system is determined by many factors such as the property of the FPA, the effect of nonuniformity correction, the condition of operation and so on. In this paper, the micro-structure and heat transfer mechanism of microbolometer FPA are analysed to find out the substrate temperature characteristic. The response nonuniformity of the FPA and corresponding two-point correction method are discussed to find out the calibration temperature characteristic. And the power dissipation property of the thermal-electrical cooler (TEC) integrated under the FPA is described to find out the ambient temperature characteristic. According to the simulation and experiment results obtained from a 320×240 amorphous silicon microbolometer imaging system, it is concluded that all these temperature parameters have a great influence on the system performance and should be well considered for different working conditions to gain high system performance and imaging quality.