光學同調斷層掃描 (Optical coherence tomography，OCT)是相當熱門的光學造影技術，尤其是應用在生醫光電的檢測上受到重視。OCT以麥克森干涉儀為基本架構，使用低同調的光源提高解析度，並對樣本做非侵入式的內部照影。
FD-OCT (Frequency Domain-Optical coherence tomography)比一般傳統的TD-OCT (Time Domain-Optical coherence tomography)具有更高的取樣速度、解析度，較易提高的靈敏度等造影特性，但因光的頻域對時域的傅立葉數學轉換關係(Fourier Transform)會造成取樣後的造影出現中央極大與鏡像對稱等破壞解析度的雜訊，因此眾多複雜的數據處理和消除雜訊的演算法也不斷被提出來。
在本論文中，我們提出一套新的光學斷層掃描系統，應用兩組相位移的演算法，將干涉數據的採樣分佈在極化光兩正交的方向上，以達一次採樣 (One Shot)的提昇及利用極化光兩正交的方向性作為在FD-OCT的phase shifting研究性實驗。為避免多餘的極化干擾我們捨棄主流的光纖式光路改採free space降低通道對極化光干擾，並利用玻片組的光延遲測試作研究討論。

Optical Coherence Tomography (OCT) is a very popular optical imaging technology, especially in the application of biomedical photography. The OCT system is based on the Michelson interferometer and the low coherence light source with increased resolution. The OCT system provides a non-invasive imaging tomography.
Compare to the conventional TD-OCT (Time-Domain Optical Coherence Tomography), the FD-OCT (Frequency-Domain Optical Coherence Tomography) has higher sampling speed, resolution, and sensitivity of imaging. Due to the Fourier transformation in the FD-OCT, the recovery time data has some noises such as symmetry mirror image and central interference to decrease the sensitivity. Many different complex data processes have been exhibited to eliminate these noises.
In this thesis, we present a new method of optical coherence tomography by using two data of phase shift algorithms based on orthogonal polarized light directions. This method can achieve the one sampling (One Shot) application of FD-OCT. On avoiding unnecessary interference with the polarization, free space type of OCT is better than fiber-type OCT. The characteristic of optical wave plate in the proposed method is also discussed.

References
[1] J. G. Fujimoto, D. Huang, E. A. Swanson, C. P. Lin, J. S. Shuman,W. G. Stinson,W. Chang, M. R. Hee, T. Flotte, K. Gregory, C. A. Puliafito, “Optical coherence tomography,”Science, Vol.254, Nov.1991,pp. 1178-1181
[2] B. E. Bouma, G. J. Tearney, “Handbook of Optical Coherence Tomography,” Marcel Dekker, Inc., 2002.
[3] X. J. Wang, T. E. Milner, J. F. de Boer, Y. Zhang, D. H. Pashley, and J. S. Nelson, ”Characterization of dentin and enamel by use of optical coherence tomography,”APPLIED OPTICS, Vol. 38, No.10, 1 April 1999.
[4] A. F. Fercher, C. K. Hitzenberger, “Measurement of intraocular distances by backscattering spectral interferometry,”Opt., Commun. 117, pp. 443-448, 1995.
[5] A. M. Kowalevicz, T. Ko, I. Hartl, and J. G. Fujimoto, M. Pollnau and R. P. Salathe, “Ultrahigh Resolution Optical Coherence Tomography Using a Superluminescent Light,”OPTICS EXPRESS, Vol. 10, No. 7, 8 April 2002.
[6] A. B. Vakhtin, K. A. Peterson,W. R. Wood, and D. J. Kane,“Differential spectral interferometry: an imaging technique forbiomedical applications,”OPTICS EXPRESS, Vol. 11, No. 8, 21April 2003.
[7] J. W. Goodman, Statistical Optics, New York, John Wiley and Sons, pp. 164-169, 1985.
[8] R. D. Guenther, Modern Optics, John Wiley and Sons, 1990.
[9] Cheong et. al. “A Review of the Optical Properties of Biological Tissues,” IEEE Journal of Quantum Electronics, 26:2166-2184, 1990
[10] Profio AE, Doiron DR. “Transport of light in tissue in photodynamic therapy of cancer,” Photochemistry and Photobiology, 46:591-599, 1987.
[11] Amnon Yariv, Pochi Yeh. “Photonics,” Optical Electronics in Modern Communications, sixth edition, chap1.6, pp.25-27.
[12] Amnon Yariv, Pochi Yeh. “Photonics,” Optical Electronics in Modern Communications, sixth edition, chap1.9, pp.45-46.
[13] Hsu-Chih Cheng, Jen-Fa Huang, and Yi-Hua Hsieh, “Numerical Analysis of One-Shot Full-Range FD-OCT System Based on Orthogonally Polarized Light,” Optics Communications, vol. 282, issue 14, pp. 3040-3045, July 2009
[14] E. Götzinger, M. Pircher, R. Leitgeb, and C. Hitzenberger, “High speed full range complex spectral domain optical coherence tomography,” Opt. Exp., vol. 13, issue 2, pp. 583-594, Jan. 2005.
[15] Yoshiaki Yasuno, Shuichi Makita, Takashi Endo, Gouki Aoki, Hiroshi Sumimura, Masahide Itoh and Toyohiko Yatagai Institute of Applied Physics, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki,305-8573, Japan
[16] M. Wojtkowski and A. Kowalczyk Institute of Physics, Nicholas Copernicus University, Grudziadzka 5/7, Pl- 87-100 Torun, Poland, R. Leitgeb and A. F. Fercher Institute of Medical Physics, University of Vienna, Waehringer Strasse 13, A-1090 Vienna, Austria August 15, 2002 / Vol. 27, No. 16 / OPTICS LETTERS
[17] Y. Watanabe, Y. Hayasaka, M. Sato, and N. Tanno, “Full-field optical coherence tomography by apochromatic phase shifting with a rotating polarizer,” App. Opt., vol. 44, issue 8, pp. 1387-1392, Mar. 2005.
[18] P. Hariharan, “Achromatic and apochromatic halfwave and quarterwave retarders,” Opt. Eng., vol. 35, issue 11, pp. 3335-3337, Nov. 1996.
[19] Leitgeb R A, Hitzenberger C K and Fercher A F 2003 Performance of Fourier domain versus time domain optical coherence tomography Opt. Express 11 889–94
[20] C. K. Hitzenberger, A. Baumgartner, and A. F. Fercher, “Dispersion induced multiple signal peak splitting in partial coherence interferometry,” Opt. Commun. 154, 179–185 1998.