根據愛因斯坦的廣義相對論中所敘述，具有加速度的物質會產生重力波(又稱引力波)。LIGO(Laser Interferometer Gravitational-wave Observatory)以超大型邁克森干涉儀，欲量測重力波，然而重力波強度極其微弱，必須降低外在雜訊的干擾，方可顯現欲觀察之訊號，因此，雜訊的降低為此量測系統中最需克服之困難。經由模擬得知，此干涉儀中最需改善之雜訊為Coating Brownian noise，是由高反射鏡上薄膜所產生。欲降低此雜訊，可將薄膜進行退火，並且於較高的退火溫度下，可達到較佳的效果，然而薄膜以高溫退火，可能造成內部產生結晶，其晶粒間摩擦將導致損耗上升。因此提升退火溫度，並維持薄膜其非晶結構為此主要目的。
本實驗中，利用離子束濺鍍法，鍍製多層薄膜。多層膜由TiO2與SiO2兩薄膜所堆疊，其中，各層之TiO2膜厚相同，SiO2亦然，並以不同層數之多層膜，區分相異之單層膜厚，如層數為三層之多層膜，其單層TiO2膜厚為42.56奈米，至於十九層結構，其TiO2厚度則為8.51奈米。將上述之多層膜以不同溫度退火，並使用XRD與TEM進行相鑑定，找尋單層膜厚與結晶溫度之關係，其結果發現，於單層厚度越薄的情況下，薄膜結晶溫度越高。TiO2薄膜結晶溫度大約為200℃，若將薄膜厚度降為8.5奈米，結晶溫度將可提升至300℃附近。利用此結果，可應用於高反射鏡中，將內部堆疊之膜厚降低，以提升結晶溫度，並以此設定為退火溫度進行退火，預期可大幅降低雜訊強度。

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