Multi-layer hollow-core PMMA tube waveguides with varying grating structures were theoretically and experimentally investigated for the terahertz (THz) chemical material sensor applications. Compared with single-layer tube, the multi-layer cases can produce a delayed response in the time domain with an improved extinction ratio. A double tube combination consisted of a thick double-groove chirped grating tube and a thin single-groove chirped grating one can realize an improved detection sensitivity. With different extinction ratio of the measured THz spectra, ethanol and vinegar can be distinguished with a sensitivity of about 18 dB/mL. The proposed multi-layer hollow-core grating waveguide can be further applied for the THz gas sensing applications.

从理论和实验上研究了具有不同光栅结构的多层空心PMMA管波导，用于太赫兹（THz）化学材料传感器的应用。与单层电子管相比，多层电子管可以在时域内产生延迟响应，并且消光比得到改善。由厚的双槽chi光栅管和薄的单槽chi光栅组成的双管组合可以提高检测灵敏度。由于测得的太赫兹光谱具有不同的消光比，因此可以区分出乙醇和醋，灵敏度约为18 dB / mL。所提出的多层空心光栅波导可以进一步应用于太赫兹气体传感应用。