利用高激发态里德堡原子对太赫兹波的频率上转换探测研究

缺少灵敏度高、响应速度快的室温太赫兹(THz)波探测器是制约THz技术发展的瓶颈之一，本项目提出利用惰性气体放电产生具有较大主量子数的高激发态里德堡原子在THz电场下的Stark效应对THz波进行频率上转换探测的新方法。利用多通道量子亏损理论研究氖、氩的里德堡原子能级结构及光谱特征，探索THz波作用下里德堡原子数量、能级的变化，揭示THz电场下里德堡原子的Stark效应；研究放电气体发光强度变化与THz波场强的关系，阐明利用惰性气体里德堡原子对THz波进行频率上转换的机制。利用正交实验法研究气体组分、压强、放电电压等参量对频率上转换效应的影响规律；研制出转换效率>1%、噪声等效功率<0.1pW/Hz^(1/2)、频谱响应范围0.1-10THz的室温THz波探测器及实时无像素成像器件，成像速度20帧/秒。本项目对推动THz波探测技术的发展及THz波与里德堡原子作用机理研究具有重要意义。

Lack of room temperature terahertz (THz) wave detectors with high sensitivity and fast response speed is one of the bottlenecks restricting the development of THz technology. This project proposes a new method for frequency up-conversion detection of THz wave by using the Stark effect of high excited Rydberg atoms with large principal quantum number produced by discharging inert gases in THz electric field. The energy level structure and spectral characteristics of Rydberg state atoms of Neon and Argon will be studied by using multi-channel quantum defect theory, the variations of number and energy level of Rydberg state atoms under THz wave will be investigated, and the Stark effect of Rydberg state atoms under THz electric field will be revealed. The relationship between the intensity of discharge gas emission and the intensity of THz wave will be studied, and the mechanism of frequency up-conversion of THz wave by using Rydberg atom of inert gas will be clarified. The orthogonal experiment method will be used to investigate the influence of gas composition, pressure, discharge voltage and other parameters on frequency up-conversion effect; a room temperature operated THz wave detector with the conversion efficiency of over 1%, noise equivalent power of less than 0.1 pW/Hz^(1/2) and spectrum response range of 0.1-10 THz and a real-time pixel-free imaging system with the imaging speed of 20 frames/second will be developed. This project is of great significance in promoting THz wave detection technology and investigating the interaction mechanism between THz waves and Rydberg atoms.