近共路徑非等光程波長掃描干涉儀在晶體參數量測之應用

Refractive Index and Thickness Determinations Using a Near-common- and Unequal-path Wavelength Scanning Interferometer

林志龍(Tzu-Lung Lin)

指導教授 ： 林世聰

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2007年)

摘要

本文提出一套波長掃描干涉儀，以該架構應用於晶體折射率與厚度的量測，它具有共路徑與非等光程之特色，且以旋轉分析板取代外差光源的架構，故具高穩定性、高靈敏度、光路架設容易與即時量測等優點。
本實驗以波長可調的二極體雷射為光源，將光源引入本論文所提干涉儀，以產生參考訊號與量測訊號兩週期性訊號，藉此分別對三個已知參數的晶體作量測。實驗中以波長計取得入射光光波長的變化及鎖相放大器取得參考訊號與量測訊號之間的相位變化，即可獲得晶體折射率與厚度參數。實驗結果証明它可應用在晶體折射率與厚度量測，本論文也對產生量測誤差之因素進行分析。

關鍵字

波長掃描干涉儀 ； 近共路徑與非等光程 ； 旋轉分析板 ； 晶體折射率

並列摘要

A new and simple interferometer based on three designs, near-common-path, unequal optical-path-length, and rotating analyzer, is proposed for refractive index and thickness of a transparent plate determinations. These designs make the interferometer with the characteristics of high stability, high sensitivity, compact optical setup, and real time measurement.
In the experimental process, a tunable laser diode was adopted as the laser source, and then measure three known parameter of the transparent plate, respectively. The variation of the wavelength of the laser beam can be measured by wavelength meter, and then the variation of the phase of the interference signal can be measured by lock-in amplifier. The measured data are substituted into the specially derived equations, and the refractive index and thickness of a transparent plate are determined. The analysis the errors of measurement are discussed. And the experimental results from applying the setup agree the validity of this interferometer.

並列關鍵字

wavelength scanning interferometer ； near-common- and umequal-path interferometer ； rotating analyzer ； refractive index

參考文獻

[34]鄭晏如，波長位移量測用干涉儀，碩士論文，國立台北科技大學光電工程系，台北，2006。

[1]R. C. Youngquist, S. Carr, and D. E. N. Davies, “Optical coherence-domain reflectometry: a new optical evaluation technique,” Opt. Lett., vol. 12, 1987, pp. 158-160.

[2]T. Tsuruta, and Y. Ichihara, “Accurate measurement of lens thickness by using white-light fringes,” J. Appl. Phys., vol. 14, 1974, pp. 369-372.

[3]B. L. Danielson, and C. Y. Boisrobert, “Absolute optical ranging using low coherence interferometry,” Appl. Opt., vol. 30, 1991, pp. 2975-2979.

[4]C. J. R. Sheppard, T. J. Connolly, J. Lee, and C. J. Cogswell, “Confocal imaging of a stratified medium,” Appl. Opt., vol. 33, 1994, pp. 631-640.