基于光学天线的多光谱窄带热探测器及其应用

Optical Antenna Based Multi-Spectral Narrowband Pyroelectric Detectors and Their Applications

在回顾热探测器的工作原理、材料体系和典型应用的基础上,着重介绍了利用光学天线调控热探测器像元的光谱响应、实现多光谱窄带探测的技术路线。首次提出了将基于光学天线的多光谱窄带探测器用于非色散红外光谱法(NDIR)进行多种气体传感的应用场景,以摆脱对窄带滤光片的依赖;针对8种典型的危害性气体(H_(2)S、CH_(4)、CO_(2)、CO、NO、CH_(2)O、NO_(2)、SO_(2))的特征吸收波长构建了多光谱窄带探测器阵列,并采用NDIR进行了单一气体检测,由实验测得的气体检测下限与商用NDIR气体传感器的检测下限相当;发展了从多个窄带探测器的输出信号组合反推混合气体中各组分浓度的数学模型,并进行了NDIR多组分混合气体实验验证。结合商业案例,分析了超构材料多光谱窄带探测技术在固体、液体、气体等形态的物质成分分析中的实用价值,展望了其在国防军事、工业化工、食品安全及污染检测等领域中的应用前景。

We first review the working principle,choice of materials and typical applications of pyroelectric detectors,and then discuss the tuning of the photoresponses of pyroelectric detector pixels using optical antennas.We propose a multiplexed non-dispersive infrared(NDIR)gas sensing platform consisting of narrowband infrared detector array as read-out.By integrating optical antenna based plasmonic metamaterial absorbers with pyroelectric detectors at the pixel level,the detectors exhibit spectrally tunable and narrowband photoresponse,circumventing the need for separate bandpass filter arrays.We demonstrate the single gas sensing of H_(2)S、CH_(4)、CO_(2)、CO、NO、CH_(2)O、NO_(2)、SO_(2),respectively.The measured detection limits of single gas experiments are comparable to commercial NDIR sensors.We also develop a mathematical model and demonstrate the deduction of the concentrations of the target gases in a mixture from the readouts of multiple narrowband detectors.Finally,we examine the capability of the narrowband detector array in the spectroscopic analysis of various solids,liquids and gases,and discuss the applications in security,military,industrial production,chemical engineering,food safety and environmental protection.