光學同調斷層攝影術(OCT)為一種利用低同調干涉術的原理，可用來量測生物組織非接觸式的斷層影像。而頻域光學同調斷層攝影術(FD-OCT)因在成像速度與靈敏度優於時域光學同調斷層攝影術(TD-OCT)，常用於生物影像的研究。但FD-OCT在成像過程中，會產生DC、自相干和鏡像雜訊，這些雜訊會造成鬼影降低系統的成像品質，因此，本研究建立一個基於平衡偵測式的FD-OCT系統，且使用一台光譜儀搭配光纖陣列的方式同時獲得兩個訊號，以達到消除DC與自相干雜訊目的。

Optical coherence tomography (OCT), based on low coherence interferometry, is a powerful tool that can support non-contact and high-speed tomographic imaging in biological tissues. Fourier domain optical coherence tomography (FD-OCT) have recently interest in
the biomedical imaging research due to their significant sensitivity and imaging speed advantages over time domain OCT. But FD-OCT has a disadvantage in that it possesses the DC noise and the inherent autocorrelation noise and mirror image noise in the final results that make the interpretation of image difficult and degrade the system performance. Therefore, in this research, we developed a balanced detection based FD-OCT system by using a spectrometer with a fiber array simultaneously receive two signals in order to eliminate dc and autocorrelation noise.

[ 1 ] D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K.Gregory, and C. A. Puliaf ito, “Optical coherence tomography”Science 254, 1178 (1991).
[ 2 ] J.A. Izatt, M.D. Kulkarni, H.-W. Wang, K. Kobayashi, and M.V. Sivak, Jr.,”Optical coherence tomography and microscopy ingastrointestinal tissues,” IEEE J. Sel. Top. Quantum Electron. 2, 1017-1028 (1996).
[ 3 ] M. Wojtkowski, A. Kowalczyk, R. Leitgeb, and A. F. Fercher, Opt. Lett. 27, 1415 (2002).
[ 4 ] J. A. Izatt, M. D. Kulkami, S. Yazdanfar, J. K. Barton, and A. J. Welch, Opt. Lett. 22, 1439 (1997).
[ 5 ] Z. P. Chen, Y. H. Zhao, S. M. Srinivas, J. S. Nelson, N. Prakash, and R. D. Frostig, “Optical Doppler Tomography,” IEEE Journal of Selected Topics in Quantum Electronics 5, 1134-1142, 1999.
[ 6 ] G. J. Tearney, M. E. Brezinski, B. E. Bouma, S. A. Boppart, C. Pitris, J. F. Southern, and J. G. Fujimoto,“In vivo endoscopic optical biopsy with optical coherence tomography,” Science 276, 2037-2039, 1997.
[ 7 ] C. Yang, A. Wax, M. S. Hahn, K. Badizadegan, R. R.Dasari, and M. S. Feld, Opt. Lett. 26, 1271 (2001)
[ 8 ] M.R.Hee,D.Huang,E.A.Swanson,J.G. Fujimoto,”Polarization-sensitive low-coherence reflectometer for birefringence characterization and ranging,” J. Opt. Soc. Am. B 9, 903-908, 1992.
[ 9 ] U. Morgner, W. Drexler, X. D. Kartner, C. Piltris, E. P. Ippen, and J. G. Fujimoto, Opt. Lett. 25, 111–113 (2000).
[ 10 ] Ruikang K Wang and Zhenhe Ma “A practical approach to eliminate autocorrelation artefacts for volume-rate spectral domain optical coherence tomography” Phys. Med. Biol. 51 3231–3239 (2006)
[ 11 ] R. Leitgeb, C. K. Hitzenberger, and A. F. Fercher “Performance of fourier domain vs. time domain optical coherence tomography” OPTICS EXPRESS, Vol. 11, No. 8 889-894(2003)
[ 12 ] S. H. Yun, G. J. Tearney, J. F. de Boer, N. Iftimia and B. E. Bouma, “High-speed optical frequency-domain imaging” OPTICS EXPRESS, Vol. 11, No. 22 2953-2963(2003)
[ 13 ] Jun Ai and Lihong V. Wang, “Synchronous self-elimination of autocorrelation interference in Fourier-domain optical coherence tomography” OPTICS EXPRESS, Vol. 30, No. 21 2939-2941(2005)
[ 14 ] Andrei B. Vakhtin, Kristen A. Peterson, William R. Wood, and Daniel J. Kane,“Differential spectral interferometry: an imaging technique for biomedical applications” OPTICS LETTERS Vol. 28, No. 15 1332-1334 (2003)　
[ 15 ] Ruikang K. Wang, “In vivo full range complex Fourier domain optical coherence tomography” APPLIED PHYSICS LETTERS 90, 054103 (2007)
[ 16 ] Christophe Dorrer, Nadia Belabas, Jean-Pierre Likforman, and Manuel Joffre,“Spectral resolution and sampling issues in Fourier-transform spectral interferometry” Opt. Soc. Am. B Vol. 17 No. 10 (2000)
[ 17 ] N. A. Nassif, B. Cense, B. H. Park, M. C. Pierce, S. H. Yun, B. E. Bouma, G. J. Tearney, “In vivo high-resolution video-rate spectral-domain optical coherence tomography of the human retina and optic nerve” OPTICS EXPRESS Vol. 12, No. 3 (2004)
[ 18 ] Delphine Sacchet,* Michal Brzezinski, Julien Moreau,Patrick Georges, and Arnaud Dubois, “Motion artifact suppression in full-field optical coherence tomography” APPLIED OPTICS Vol. 49, No. 9 2010
[ 19 ] Erich Götzinger, Michael Pircher, and Christoph K. Hitzenberger, “High speed spectral domain polarization sensitive optical coherence tomography of the human retina” OPTICS EXPRESS Vol. 13, No. 25 10217 (2005)
[ 20 ] Bernhard Baumann, Erich Götzinger, Michael Pircher, and Christoph K. Hitzenberger, “Single camera based spectral domain polarization sensitive optical coherence tomography” OPTICS EXPRESS Vol. 15, No. 3 1054 (2007)
[ 21 ] Cheol Song, MyoungKi Ahn and DaeGab Gweon, “Polarization- sensitive spectral-domain optical coherence tomography using a multi-line single camera spectrometer” OPTICS EXPRESS Vol. 18, No. 23 23805 (2010)
[ 22 ] Chuanmao Fan, Yi Wang and Ruikang K. Wang, “Spectral domain polarization sensitive optical coherence tomography achieved by single camera detection” OPTICS EXPRESS Vol.15 No.13 7950 (2007)
[ 23 ] A. M. Rollins and J. A. Izatt, "Optimal interferometer designs for optical coherence tomography," Optics Letters, vol. 24, pp. 1484-1486, 1999.
[ 24 ] A. G. Podoleanu, "Unbalanced versus balanced operation in an optical coherence tomography system," Applied Optics, vol. 39, pp. 173-182, 2000
[ 25 ] R. Leitgeb, C. K. Hitzenberger, and A. F. Fercher, “Performance of fourier domain vs. time domain optical coherence tomography” OPTICS EXPRESS Vol. 11, No 8 889 (2003)