傳統型光學濾波器結構是以多層薄膜堆疊 (stacked thin-film) 的方式為主，利用多層薄膜堆疊的結構所產生的干涉現象來達到濾波的效果；但是由於多層薄膜堆疊的結構在製作技術上較常使用與大尺寸、大尺度下，對於與MEMS做結合的小尺寸下，利用鍍膜是較難達成的，對於結構中各層材料舉凡是折射率、厚度、均勻性、甚至是膜層間的應力都需要仔細加以考慮，為了要使結構更簡單而且更輕薄化， 本論文在結構上提出矽基板懸浮式導波模態共振濾波器 (Si-based Suspended-Membrane-Type Guide-Mode Resonance Filter) ，結構總厚度約 1 μm左右，相對於以往多層薄膜堆疊的光學濾波器來說，不僅結構較為簡單，製作上也更為便利，同時亦能精準的控制其結構參數。 本文在懸浮式導波模態共振濾波器設計上，藉由加入一低披覆層 (lower cladding layer) 提升結構頻譜的品質因素 (Q factor) 約50％左右，以實作與量測結果驗證製程的能力與設計的可信度；另一方面藉由控制低披覆層的厚度來提升頻譜側帶 (sideband) 的穿透率，在波段 1.2 - 2.0 μm 的穿透率高於90％，這與以往的導波模態共振濾波器做比較，高穿透率的側帶區域增加了約 400 nm 左右，可提升在一寬頻譜波段內的濾波效果。經由本研究的設計、製作及量測結果提出一低披覆層之懸浮式導波模態共振濾波器取代傳統濾波器，並提升元件濾波特性在頻譜寬度長達約 671 nm 的範圍，不僅使得懸浮式導波模態共振濾波器的實用性大幅擴展，更使其在市場應用上更具價值與競爭力。The structure of traditional optical filter is mainly stacked by multi-thin-film, using the interfered phenomenon produced by the structure of stacked thin-film to get the effect of filtering light wave.Nevertheless, due to large size elements are frequently used in producing stacked thin-film structure, it is hard to combine with MEMS that is a tiny element by coating, to seriously allow for the factors such as refraction index, thickness, homogeneity and even stress between thin-film in each layer is necessary. In order to simplify the structure, this thesis represents Si-Based Free-Standing Guide-Mode Resonance Filter which total thickness is about 1 μm . Comparing with traditional optical filter stacked by multiple thin-film,when using Free-Standing Guide-Mode Resonance Filter, its structure become more uncomplicated and producing progress get more handy.Moreover, structure parameter can be exactly controlled as well.On design of Free-Standing Guide-Mode-Resonance Filter in this thesis, Q factor of structural spectrum can be promoted about 50% by adding low cladding layer. This thesis experimented to prove iv practicability of the design. Besides, this thesis controls the thickness of lower cladding layer to raise the transmission efficiency of sideband and make transmission efficiency more than 90% when wavelength is from 1.2 - 2.0 μ m . Differing from traditional Guide-Mode Resonance Filter, the sideband of high transmission efficiency can be increased around 400 nm with promoting the filter efficiency in a broadband. A Suspended-Membrane Type Guide-Mode Resonance Filter with lower cladding layer can be realized to substitute the traditional filter by our design, analysis, fabrication and measurement results. In addition, the practicability of Free-Standing Guide-Mode-Resonance Filter can be generally applied and its value and competitiveness will increase in market application.
