本論文為分析金屬銀的光學常數在膜層厚度 10 ~ 100 nm 時的變化，並利用不同厚度銀的光學常數設計出可見光波段的中性分光鏡。實驗第一階段中利用濺鍍沉積法鍍製不同厚度銀膜，並使用橢偏儀量測膜的橢偏參數，再用 CompleteEASE 軟體擬合膜層的光學常數 n、k。實驗第二階段使用 Macleod 軟體設計並模擬膜層的穿透反射光譜，利用第一階段得到的銀的光學常數做分光鏡膜層設計，並以濺鍍沉積法鍍製出分光鏡，以多角度積分球光譜儀量測光 45 度角入射至分光鏡的穿透、反射光譜。 由於薄膜模擬軟體：如 Macleod，軟體內材料的光學常數 n、k 皆為塊材(Bulk)的光學常數。而金屬膜在厚度薄的狀況下，其光學常數與塊材的光學常數有很大的不同。故膜層中若有薄的金屬膜，模擬的光譜圖會跟實際光譜有差異。本實驗建立出薄 Ag 光學常數到塊材 Ag 光學常數的趨勢，使未來膜層設計時更精準。;In this research, we investigate the optical constants of ultra-thin silver films of thickness from 10nm to 100nm, and then design a neutral beam splitter applied in visible light using the optical const ants we’ve got. First, the silver films of different thickness were deposited onto glass substrates using sputtering deposition, and then measured by spectroscopic ellipsometry to investigate the film optical constants. Later , we designed the beam splitter with the optical constant we’ve got and made the beam splitter using sputtering. Finally, we measured the spectrum of the beam splitter with the light incident angle of 45 degree. Thin film design software, like Macleod, has material optical constants database with the bulk material. With ultra-thin film optical constants, we could have better simulation result in our design.
