铁电薄膜在红外辐射作用下的响应

研究了红外探测器中红外焦平面列阵的象元———铁电薄膜微桥在红外辐射作用下的输出信号。用层合板壳作为微桥结构的力学模型,中间一层为压电材料,上下两层为金属材料电极。采用了力-热-电耦合的控制方程和变分原理,推导出了基于Mindlin假设的压电材料层合板有限元公式。以红外探测器在夜间从飞机上探测地面的坦克为例,用有限单元法模拟了铁电薄膜微桥在红外辐射作用下的力、热、电输出信号,并对结果作了分析比较。

Responses of a ferroelectric thin film under infrared radiation

The response of a microbolometer pixel structure,the essential component part in an infrared focal planar array of an infrared detector,to an infrared radiation was analyzed.The pixel structure was modeled as a composite laminate thin plate.Its middle ply was a PZT ferroelectric thin film.Its top surface,the infrared absorber,was covered with gold,while the bottom surface was deposited with reflection metal: platinum.Meanwhile both surfaces were a pair of electrodes.The thermal-electric-mechanical coupling variational principles were established based on the governing equations.The finite element equations for composite laminate plates with the Mindlin assumption,corresponding to the variational principles,were formulated.Taking the example that a tank on a sand ground was detected from the air at night,the displacement,temperature change and electric output signals of the microbolometer pixel structure were simulated by means of the finite element method.The results from the simulation were analyzed.