相位移動器校正之研究

Calibration of the phase-shifting adapter

盧立瑋(Li-Wei Lu)

指導教授 ： 歐陽盟

國立中央大學/理學院/光電科學研究所/碩士(2006年)

摘要

相移精度於相移干涉術之量測，是最可代表樣品資料之可靠度。對利用相移干涉術來量測樣品之干涉儀而言，不準確之相移會在計算物體相位上產生誤差。本系統之相位移動器係由三個壓電致動器所構成，因為壓電致動器本身之差異與結構上受到不同應力之影響，在移動的過程中會產生移動不均的問題，意即在推進過程中改變參考面之法線向量，最直接的觀察方式為推動一週期後比較前後之干涉圖，干涉條紋有旋轉與間隔改變之現象，此現象亦反應在相位移之標準差。
針對此問題之解決方式，本論文提出一種校正相位移動器的方式，從理論推導出壓電致動器位移與條紋斜率之關係，從此關係中找出一特殊情況來校正，此方式利用條紋之變化來對壓電致動器之差異進行個別調校，從比對第一張與最後一張影像之差異變化，可發現利用此方法所得到之權重比例，的確改善了移動不均之現象。

關鍵字

相位移動器 ； 相位移校正 ； 壓電材料

並列摘要

The error of the movements of the phase-shifting adapter(PSA) determines the accuracy of measurement to a large degree. For large-apeture and weighty optical elements, we usually use an adapter with three PZTs to hold the tested optical element. It is very important to keep the adapter stretched as a flat. Otherwise, the shifting fringe patterns will rotate, and the distance between fringes will be changed. These phenomena will decrease the precision of phase-shifting interferometry.
In this thesis, a method to calibrate a phase-shifting adapter with three piezoelectric ceramics based on the relationship between the displacement of PZT and the slope of interference fringe is proposed to increase the testing precision of phase-shifting interferometer. Observing the first and the last interferograms, the unequal movement of the PSA is improved by this method.

並列關鍵字

phase-shifting adapter ； phase-shifting calibration ； piezoelectric ceramic

參考文獻

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