本論文成功展示混合型次波長波導於兆赫頻段，構成波導的介質層包括塑膠線、高分子彩帶與一維金屬週期結構，每一種結構層的截面尺寸，均小於兆赫波繞射極限尺寸，其個別傳輸兆赫波的波導特徵，均以次波長波導模態，形成強而明顯的消逝場於波導核心外的空氣披覆層，此兆赫次波長波導具有長距離傳輸與線性極化兩大特色，是目前兆赫科技實現波導技術最重要的方法，此論文使用已經發表的兆赫次波長波導介質，包括聚乙烯(Polyethylene, PE)塑膠線、聚偏二氟乙烯(polyvinylidene fluoride, PVDF)高分子彩帶以及一維金屬週期狹縫結構等。為了實現混合型次波長波導，此論文探討整合所需之空間配置與參數，包括金屬薄膜整合PE線、PVDF彩帶整合PE線、PVDF彩帶與金屬薄膜整合PE線、薄膜整合金屬週期結構等；研究結果發現，PE線整合金屬薄膜，並操作在橫向磁波模態(Transverse Magnetic, TM, mode)的條件，整合PVDF彩帶可以展現最高的感測靈敏度，此論文以葡萄糖分子校準此混合型波導之感測表現，所能感測到的最低葡萄糖分子數量為2.3 nmol/mm2。依據此PE線為基礎的兆赫次波長混合波導，此論文成功實現孔隙薄膜感測與抗體－抗原生物分子感測等應用，以聚醯亞胺(Polyimide, PI)孔隙薄膜為例，最小可解析感測光程為1.626 μm-RIU，經由等效介質理論模型，推算薄膜的物理厚度與折射率，其誤差分別為17.44 %和6.6 %；此外，以聚乙二醇單甲醚-生物素(mPEG-Biotin)之抗體分子、鍊親和素(Streptavidin)之抗原為例，感測抗體複合前、後的最小可解析分子變化量，分別為91.9 pmol/mm2和18.1 pmol/mm2。其中，孔隙薄膜感測將提供兆赫通訊元件的基板檢測，而抗體－抗原生物分子感測，將提供未來生物醫藥偵測平台，可以輕易結合兆赫波微量感測技術與光學顯微鏡，使用顯微鏡過程就可以從兆赫波訊號得知分子間結合力的存在，解決目前兆赫波微量感測無法整合光學顯微鏡的窘境。

Two types of hybrid subwavelength waveguides are successfully demonstrated in the thesis for optical sensing via terahertz electromagnetic waves. One is the ribbon-integrated-wire waveguide and the other one is the superstrate-integrated periodic metal waveguide. The thesis investigation indicates that their sensing mechanisms are different. The ribbon-integrated-wire waveguide realizes optical sensing based on the fundamental of a waveguide coupling effect. For the superstrate-integrated periodic metal waveguide, its sensing mechanism follows the refractive-index-sensitive Bragg resonance. Both the integrated elements of a ribbon and a substrate can be operated as sample adsorbers to achieve optical sensing purpose because of their nano-porous and hydrophilic features. The glucose is used as a standard molecule to optimize the engineering parameters of waveguide cores in the two waveguide sensing schemes. The thesis investigation presents that the plastic wire core with a specific metal-thin-film surface is critical to enhance the sensing ability because the wire-guided terahertz field can be modified to match the transverse-magnetic mode of a ribbon that is loaded with a sample. Furthermore, such the wire waveguide scheme has a higher sensitivity than that of a periodic metal waveguide around 386%. Finally, the waveguide sensing scheme of a ribbon-integrated-wire waveguide realizes optical sensing to recognize porosity and antibody-antigen molecules on the polymer layers.

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