共路徑非等光程干涉儀及其應用

A Nonequal- and Common-path Interferometer and Its Application

張政中(Cheng-Chung Chang)

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

本論文提出一套創新的波長位移量測用偏光干涉儀，它屬共路徑與非等光程類型，故具有高靈敏度與高穩定性的特點，並以旋轉分析板的設計使光路架設容易，且即時與非波壞性的量測為其優點。
經量測後說明其具有K=269.67 degree/nm的靈敏度且3×10-4 nm的穩定度。實驗應用上，將干涉儀針對光纖光柵感測器受負載後作應變量測，將光纖光柵貼附於四點彎曲樑上後施力，藉由相位變化的觀察與干涉儀的靈敏度，求得波長漂移後，光纖光柵受力產生的應變即可測得。將系統參數代入平面應力與平面應變理論的公式推導，以及利用應變規作為量測參考標準，量測結果與參考標準值具有相當的一致性，也證實本論文所提出偏光干涉儀的正確性與實用性。

關鍵字

波長漂移術 ； 光纖光柵 ； 旋轉分析板

並列摘要

This thesis proposes a novel interferometer for determining wavelength shift. It is a nonequal- and common-path interferometer, and it uses a rotating analyzer to generate AC signals so the phase corresponding to the wavelength shift can be extracted. A nonequal- and common-path interferometer is a high sensitivity and high stability one, the use of the rotating analyzer simplifies the setup of the interferometer.
The principle of the proposed interferometer is introduced. A setup constructed to calibrate this interferometer was developed. The experimental result shows that the interferometer had a sensitivity of 269.67 degree/nm. Besides, the setup was also adopted for testing the stability of the proposed interferometer, the result shows that it was 3×10-4 nm.
To verify the applicability of the interferometer, it was adopted to determine the wavelength shift of the wave reflected from a fiber Bragg grating bonded on a loaded four-point bending beam. A transformation from the wavelength shift to beam strain was done and it was finally compared with theoretical strain and strain gauge. The comparison agrees the applicability of the interferometer.

並列關鍵字

wavelength shift technique ； fiber Bragg grating ； rotating analyzer method

參考文獻

[43] 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所，台北，2006。

[2] H. Kikuta, K. Iwata, and R. Nagata, “Distance measurement by the wavelength shift of laser diode light,” Appl. Opt., vol. 25, pp.2976-2980, 1986.

[3] T. Zhang, and M. Yonemura, “Multipass Michelson interferometer with the use of a wavelength-modulated laser diode,” Appl. Opt., vol. 35, pp.5650-5656, 1996.

[4] Y. Otani, A. Tanahashi, and T. Yoshizawa, “Light source with orthogonally linear polarized two-frequency beam from laser diode and surface profile measurement,” Opt. Eng., vol. 35, pp.1070-1073, 1996.

[5] A. Yamamoto, and I. Yamaguchi, “Surface profilometry by wavelength scanning Fizeau interferometer,” Opt. Laser Technol., vol. 32, pp.261-266, 2000.