- 學位論文
創新式白光干涉儀線上防振技術研製
Innovative Anti-vibration Technique for On-line White-light Vertical Scanning Interferometry (VSI)
摘要
本研究設計一套白光干涉即時防振干涉儀，系統光源以白光LED，搭配帶通濾波片、Mirau干涉物鏡與PZT壓電陶瓷位移控制器等光電元件，利用雙相機同步取像，以垂直掃描干涉技術為基礎，建構在Mirau顯微干涉光路架構上。因為本系統使用雙相機架構，故須先將光源亮度調制恰當，光源經過非偏極分光鏡後，改變行徑方向，並通過Mirau干涉物鏡後；利用其內部特製之分光鏡以及參考鏡與待測物之反射光形成干涉。並利用白光僅能於近似零光程差時方可產生干涉的原理，搭配PZT壓電陶瓷位移控制器垂直掃描得到不同高度時之光強資訊。利用曲線擬和以及相關演算法找出光強峰值，並可推算物體之表面輪廓尺寸，使其能克服傳統相移法無法量測斷高之問題。但於掃描過程中極易受到環境振動干擾，影響到量測之穩定性與正確性。因此本研究設計以高速取像相機與原有量測之相機同步取像，並且利用帶通濾波片將原有白光光源濾成近似單一波長光源，使其同調長度增加。如此對於系統受到環境振動影響時利用高速相機即時取得干涉條紋飄移之影像。並可達到即時位移偵測的目的。補償原有白光干涉系統因環境擾動所帶來之量測誤差，以讓白光干涉儀可以達到線上使用之目的。因此在實驗部分，將建立一套實驗系統以驗證系統之可行性和探討與分析相關問題。且系統經過重覆性量測後，量測結果平均量測階高為2.427
並列摘要
White light interferometer (WLI) has become a popular method for measuring micro surface profiles having a large height range with a nano-scale resolution. However, it is easily influenced by environmental vibration or noisy disturbances, which significantly restricts its usefulness and application for in-field inspection. Tremendous research effort has been invested to overcome the vibration-induced measurement problems. Thus, in this research, a novel white-light optical interferometric system was developed to minimize measurement errors potentially caused by environmental vibrations. The novel developed systemTM is composed of a white-light LED light source, a narrow bandpass filter, a Mirau objective, a PZT for vertical scanning and two image sensing devices. Using the development, the vibration displacement can be accurately monitored and compensated for accurate vertical scanning interferometry (VSI). From the preliminary experimental results, it is verified that nano-scale displacement detection for a vibration having a bandwidth of 20 Hz can be effectively achieved. The feasibility of the anti-vibration white-light VSI is further verified by performing an industrial in-field test.