基于KID探测器阵列双傅立叶变换成像系统研究

THz band is essential for research on dark matter and dark energy, formation and evolution of galaxies, matter recycling among stars and interstellar medium, planets origination, high-redshift galaxies as well as cosmic background radiation. THz spectroscopy astronomical observations involve continuous spectrum and line spectra observations. Previous research result reveals that there are often abundant line spectra in continuous spectrum radiation arised from molecular and atomic gases at THz band. When carrying out imaging observation of continuous spectrum and line spectra simultanously, astronomers could obtain multi-dimensional images of celestial objects, which will help to further reveal their complex and intrinsic characteristics. Due to application requirements for astronomical multi-dimensional image observations at THz band, we plan to conduct research on double Fourier transform imaging system based on KID detector array, including research on key technologies of the imaging system, multi-dimensional image numerical simulation methods, and detection experiment of target multi-dimension image based on this prototype imaging system. This project will break through the key technologies of multi-dimensional image detection, and then will lay a solid technical foundation for achieving multi-dimensional image detection of the next generation THz superconducting array imaging system, which will plan to be equipped on Antarctic 5m THz telescope. Multi-dimensional image detection technologies involved in this project have wide application prospects, which can also be used in other fields such as biomedical, Earth's atmosphere, manned space THz astronomy programs, and national related aspects etc.

太赫兹波段是研究暗物质与暗能量、星系形成和演化、恒星与星系介质间物质循环、行星起源、高红移星系、以及微波背景辐射的重要波段。 太赫兹天文观测包括连续谱观测和频谱观测。研究发现在太赫兹波段在连续谱辐射天区往往存有丰富的分子原子谱线，对天体观测对象同时开展连续谱和谱线图像观测，则可获得天体观测对象的多维图像，这将有助于进一步揭示其更为复杂的本质特征。 针对太赫兹天文多维图像观测的应用需求，本申请开展基于KID探测器阵列双傅立叶变换成像系统研究，主要包括成像系统关键技术研究、目标多维图像探测数值仿真方法研究、以及目标成像探测实验研究。 本申请项目研究将突破多维图像探测关键技术，为我国南极5米太赫兹望远镜的下一代主要观测设备，太赫兹超导阵列成像系统实现多维图像探测打下坚实的技术基础。多维图像探测技术在其它领域，如生物医学、地球大气、载人航天太赫兹天文计划、以及国家需求相关方面具有广泛的应用前景。

本项目研究了基于KID探测器阵列双傅立叶变换成像系统关键技术，完成了成像系统构建和目标成像演示探测，为将来太赫兹天文目标多维图像探测打下坚实的技术基础。本项目取得的主要研究进展包括：1) 解明了基于KID探测器阵列双傅立叶变换成像系统，完成了基于KID探测器阵列双傅立叶变换成像系统的关键技术包括实时FFT频谱处理、信噪比优化、相位校准、目标成像数据处理等技术研究。2) 完成了基于POST望远镜的KID探测器阵列成像演示试验系的太赫兹信号传输特性仿真，并获得了8×8 KID探测器阵列各像元波束效率矩阵，为开展目标信号辐射特性成像探测提供参考。3）完成了KID探测器阵列频分复用读出电路研制、KID探测器阵列特性实验方法研究和实验表征，试验测试KID探测器灵敏度NEP为3.3 × 10-17W/√Hz，性能达到国际水平。4) 完成了基于POST望远镜的 8×8 KID探测器阵列成像演示试验系统构建，并首次成功实现太阳、月亮850微米波段太赫兹辐射特性图像。