开展基于塑料闪烁光纤的宇宙线缪子测量研究时，对闪烁光纤输出光脉冲的光子数定量分析，是读出电子学设计的前提。在无单光子源等弱光标定时，对缪子入射事件在光纤中产生光脉冲的光子数进行定量分析是本文的主要目标。首先利用硅光电倍增管（Silicon Photomultiplier Tube，SiPM）固有的非光生载流子特性标定光脉冲的测量值，获得缪子在直径1 mm和2 mm光纤中产生微弱光脉冲包含的光子数；然后结合Geant4软件模拟计算缪子在光纤中理论光子产额，并与实验结果对比验证。结果显示，在直径1 mm和2 mm光纤中光脉冲光子期望值分别为44个和85个，与模拟结果偏差分别为4.55%和10.59%，表明该低光子数测量方法可以在无额外标定设备时，实现对缪子入射光纤产生光子数的准确测量，并可以应用在其他弱光脉冲光子数测量场景中。

Terahertz (THz) topological photonic structures are promising for last-centimeter communication in intra/interchip communication systems because they support bit-error-free THz signal transmission with topological robustness. Active and dynamically tunable THz topological photonic components have not yet been experimentally realized. Here, we experimentally demonstrate a THz topological switch (270–290 GHz) based on a valley Hall photonic crystal structured high-resistivity silicon substrate, in which the THz waves can be dynamically turned on/off by an external 447 nm continuous-wave laser. Our device exhibited an on/off ratio of 19 dB under a pumping light intensity of 240mW/mm2. The 3 dB switching bandwidth was ∼60kHz.

We employed a metallic wire grating loaded with graphene and operating in total internal reflection (TIR) geometry to realize deep and broadband THz modulation. The non-resonant field enhancement effect of the evanescent wave in TIR geometry and in the subwavelength wire grating was combined to demonstrate a ～77% modulation depth (MD) in the frequency range of 0.2–1.4 THz. This MD, achieved electrically with a SiO2/Si gated graphene device, was 4.5 times higher than that of the device without a metal grating in transmission geometry. By optimizing the parameters of the metallic wire grating, the required sheet conductivity of graphene for deep modulation was lowered to 0.87 mS. This work has potential applications in THz communication and real-time THz imaging.