基于频分复用的大规模超导阵列探测器读出关键技术研究

Astronomical observations of terahertz imaging have become the important tools to study the astrophysics for astronomers. It is difficult to increase the sensitivity of a single detector at present. Another way is to enlarge the detector numbers of receiver to improve observation efficiency. During the last decade, some array receivers such as SCUBA, LABACA and so on have been developed and used for routine astronomical continuum imaging observations. These successful applications are the symbol that radio astronomical receiver is changing from pursuing the sensitivity of single detector to large array. This project, which is to study the key technology of the electronic readout system of array detector, is based on the new type superconducting KID array detectors and FDM principle. We will explore an effective method for signal readout of the next generation large scale array receiver by designing, simulating, verifying and analyzing on the aspect of hardware, firmware and software, and by the observation results integrated with a small telescope. This work will lay the foundation of development of the antarctic and space terahertz array receiver system in future.

太赫兹天文成像观测已经成为天文学家进行天体物理学研究的重要手段。目前，提升单个探测器灵敏度已经比较困难，可以通过增加接收机探测器数量的方式来提高观测效率。十多年来，一些阵列接收机如SCUBA，LABOCA等相继被研制并应用于常规天文连续谱成像观测，这些阵列接收机的成功应用标志着射电天文接收机正在从追求单个探测器灵敏度向大规模阵列方向发展。本申请项目即基于新型超导KID阵列探测器及频分复用原理，研究阵列探测器电子学读出系统的关键技术，分别从硬件、内核、软件三个方面进行设计、仿真、验证、分析，并结合系统在小型望远镜上的观测结果，探索适合下一代超大规模阵列接收机系统信号读出的有效方法，为将来南极及空间太赫兹阵列接收机系统的研制打下基础。

本项目主要开展基于频分复用原理实现超导动态电感探测器（KID）阵列信号同步读出的关键技术研究，填补我国在该技术领域的空白，为我国研制下一代大规模太赫兹超导阵列成像系统打下坚实基础。本项目取得的主要研究进展包括：1）突破了通过微波信号频分复用读取太赫兹超导KID阵列探测器探测信息的关键技术，成功研制了基于超导KID阵列探测器的读出系统原理样机，可以满足百像元量级该类型探测器探测信息的同步读出；2）通过研究影响超导KID探测器灵敏度的内在因素，成功研制了基于零差混频原理的探测器读出电路，并基于此电路实现对超导KID探测器噪声性能的测量表征；3）通过研究影响探测器读出信号质量的噪声产生机理，优化读出方法，提高信号读出质量和效率，完成千像元量级超导KID阵列探测器读出方案。此外，本项目还通过集成超导KID阵列成像接收机、读出系统及POST亚毫米波望远镜，实现天文演示观测，为将来KID型超导阵列成像系统的天文应用奠定基础。