於本文中,我們介紹了一種在光學鍍膜時計算變動折射率的方法。藉由光學學理的推演,以及監控圖形在每層初始點和轉折點的穿透率(或反射率)資訊,我們找出各層膜厚及折射率。進而,我們可以推算出對中心波長做膜厚誤差補償的厚度。搭配高靈敏度的監控波長,我們可以更準確的預測切點,以製鍍出更符合設計的成品。本研究成功在離子輔助電子槍蒸鍍系統中利用新型光學監控法鍍製出窄帶濾光片,達到中心波長不飄移、穿透帶半高寬更符合設計值的效果。 We introduced a way to estimate the fluctuation of refractive index during thin film deposition through an optical monitor. The thicknesses and error compensated thickness for each layer were analyzed. A novel monitoring method was thereby derived. With revised refractive index and the choice of high sensitive monitoring wavelengths helps us to predict the termination points more accurately. The performance of a narrow band pass filter monitored by this method was demonstrated.