红外探测器TPS434低温、磁场性能研究

Study on TPS434 Infrared Detector at Low Temperature and Magnetic Field

以商用高灵敏度红外探测器TPS434为研究对象,测量了其灵敏度随温度(280～10K)、辐射的调制频率、磁场变化(0～6T)的相关信息。从实验结果得到:TPS434的灵敏度随着温度降低而降低,随辐射的调制频率增加而衰减,但是低温下的衰减速率变缓,说明探测器的弛豫时间变短;热电堆的温差电动势在低温下会随磁场发生线性变化,可以通过线性拟合扣除磁场对测量结果的影响。由实验所得数据估算等效噪声功率NEP以及最小可检测功率Pmin,对TPS434作为THz探测器的可行性进行了分析。

The response of a commercial thermopile TPS434 to IR light as a function of temperature between 280 and 10 K, chopper frequency between 0.1 and 100 Hz, and magnetic field between 0 and 6T was measured in order to investigate its suitability for THz detection. The data show that the sensitivity of TPS434 decreases with the decrease in temperature or the increase in chopper frequency. The relaxation time of TPS434 at low temperature is smaller than that at room temperature, which can improve the system response time. Thermopile’s thermoelectromotive force increases linearly under low temperature with the magnetic field increasing, but the influence of the magnetic field can be deducted through the linear fitting to the measurement result. The possibility of using the device as a THz detector was analyzed by estimating the equivalent noise power （NEP） and the smallest detected power Pmin.