微测辐射热计型室温太赫兹探测器耦合机制与一体化设计方法研究

Scarcity of direct terahertz detector which can operate at room temperature is one of the most difficult points in the field of international terahertz technology. And the difficult scientific problems of the room temperature direct terahertz detector are the developments of terahertz absorber with high absorptivity and microbolometer with high sensitivity..This project intends to explore the operating mechanism of the room temperature terahertz coupling detectors, and study the integrated design methodology and model. Through this research, a systematic and integrated design approach can be obtained by just using the theory in electronic field. This approach is well suited for the analysis and design of the room temperature terahertz coupling detector with multilayer films configuration and complicated structure. Therefore, this approach is capable of revealing the coupling mechanism and interaction effects of terahertz absorber and microbolometer under complex conditions. As a result, this method can solve the problem caused by different subject areas and design principles have been adopted respectively for the design of the terahertz wave absorber and microbolometer. And it can also overcome the design contradictions between the terahertz wave absorber and microbolometer. A novel room temperature terahertz coupling detector with omnidirectional, polarization-insensitive and broadband absorber and double-sacrificial-layer microbolometer was proposed; then further modeling and simulation experiments will be established for the proposed room temperature terahertz coupling detector in order to enhance the terahertz detection performance. So these research results can lay the foundation for the development and application of the terahertz detectors which are supposed to meet the requirements of higher responsivity, larger dynamic range, faster response, working at room temperature, and easy large scale integration. Moreover, these research results can be also used for the analysis and development of the other kind photodetectors.

在常温下实现直接太赫兹探测是国际太赫兹技术领域最大的难点之一。其科技难题在于测辐射热计型太赫兹探测器良好的太赫兹波吸收耦合机制和高灵敏度微测辐射热计结构的设计与实现。.本项目通过探索基于测辐射热计的室温太赫兹耦合成像探测器工作机理，研究室温太赫兹耦合成像探测器一体化设计方法与模型；提出一套基于电学域的一体化分析复杂膜层和结构的室温太赫兹耦合探测器的系统性策略，分析复杂器件结构条件下太赫兹吸收器与测辐射热计热敏结构的相互影响耦合机制，解决目前吸收与热敏元件采用不同学科知识分别设计带来的问题，克服其对器件材料和结构几何参数的矛盾要求。基于前述研究结果，为设计与建模仿真分析新型的室温宽频共面极化不敏感太赫兹耦合成像探测器，为高响应率、室温工作、快速响应、便于大规模阵列集成的太赫兹成像探测器开发与应用奠定理论基础；也为其他光电探测器的研究提供一种分析方法。

在常温下实现直接太赫兹探测是国际太赫兹技术领域最大的难点之一。其科技难题在于测辐射热计型太赫兹探测器良好的太赫兹波吸收耦合机制和高灵敏度微测辐射热计结构的设计与实现。项目的主要研究内容包括三个方面：1、研究具有高吸收率、宽频、极化不敏感特性的THz吸收器以及THz吸收器等效电路模型；2、研究室温THz探测器一体化等效电路模型；3、研究室温THz探测器一体化设计和耦合机制。设计出了一种具有高吸收率、宽频、极化不敏感特性的THz吸收器，所设计的吸收器具有优异的光学性能，对TE/TM极化电磁波不敏感，吸收带宽达到3.7THz，在1.95THz-5.65THz范围内的平均吸收率超过了96.66%。利用传输线原理对THz吸收器等效电路进行了研究，计算了吸收层的等效RLC集总参数，并且通过分析耦合机制，得到了THz探测器的一体化等效电路模型，通过和有限元仿真结果进行对比，验证了等效电路的正确性。分析了THz吸收器和微测辐射热计的耦合机制，发现采用新型桥面和L型桥腿结构的探测器具有较好的光学吸收性能，而采用折叠型桥腿结构的探测器吸收率相对较低；采用折叠型桥腿的探测器热响应比采用L型桥腿结构的探测器高90%左右，但是采用折叠型桥腿的探测器工作速度较慢。上述三个方面的研究成果为进一步的研究器件响应的数学模型与数值表征方法奠定了基础；为高响应率、大宽带范围、室温工作、快速响应、便于大规模阵列集成的太赫兹成像探测器开发与应用奠定理论基础；同时也为其他光电探测器的研究提供一种可行的分析方法。