7 H Sae Mulli (The Korean Physical Society), Volume 56, Number 5, 2008&cedil

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(1) ¨ ½ Hë 7 H Sae Mulli (The Korean Physical Society), Volume 56, Number 5, 2008¸ 5 4, pp. 439∼443 Z. ú T Þ n «à Å Ã ºõ § à u Å° Ã ÑV Ë È. ¥7 _T $ [õ §T u Þ Ó ¢S X Ä Ø¶ Z £ ¤

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(93) Ä 3 »Y Us $ \ ¦s 6 xô Ç· · · – % I 3 × æ1 x p. -441-. Fig. 3. Output spectrum of the dual cavity wavelength swept fiber laser with two different SOAs. The wavelength swept fiber laser has the spectral bandwidth of 60 nm.. Fig. 2. Output spectrum of the wavelength swept fiber laser with (a) the SOA having the shorter center wavelength and (b) the SOA having the longer center wavelength, respectively. The SOAs have the same spectral gain bandwidth of 40 nm. õs . 8 ¤& £. ñ a@ ) /% ; i ¤ r É 60 nm Ð" fé { ß _ 9 SOA\ ¦ 6 xô Ç . Ä â º Ð 8¹ ¤ V ¡ , r @ É /% ; i ¤` ¦ spectrum` ¦ ¤& £ 8. ½ ñ ÉÃ + ºe % Ü 3 ¼ y y _ SOA_ @ /% ; i ¤` ¦½ Ë + ;° 2 ‫כ‬ ú Ð H H ` ‫כ‬ ¦· Ã ú ºe . s H: r ½ ¨$. í ¸\ " f 6 x a¿ ) º> h_ SOA_ × æd

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(105) Ä 3 »& e ¦ Qü < balanced receiver (DC-10MHz, 2117, New Focus)\ ¦ x 6 % i . X s > O 8 ¤& £. ñ a

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(109) Ç² ô GÓ D to ü Æ < rt “D hÓ to ü ”, Volume 56, Number 5, 2008¸ 5 4 Z. -442-. p c P 8 ýò > k r : ½ ¨ H t d . ] â jÂ Ò_ ß í\ l O Õ tl ü ì Í ø ¸$. í \ (no. O B0008381)_ { Â 9 Òt " ¶\ é _ K s À Ò# Q& _ vm þ .. pw c Y Ã Ø U ô . Fig. 5. OCT image of the rat eye by using the proposed dual cavity fiber laser source.. æ_ × ì rK 0 x p r É 14.5 µm & . ñ ¸ Ð \ V8 ¤ £ ¦ z ´+ >` « ¦ Ã º ' % i . Fig. 5 H& Ø h ¦ az ) ´+ >6 « x1 A_ ß î½ ¨_ OCT é ß xs £ 8 p t \ ¦ Ð# Å Ò ¦e . s p t H 512 × 1024 i ! q s K _ © ¸\ ¦ t ¦e . 1 Aî ½ ß ¨_ y } õ Ã º&. ^ ñ , < ª. < G ü ¸ ^ ª _ { 9 Â Ò%. % ò s i ½ ¨ì rH d` ¦· Ã ú ºe .. IV. + Ç s. Ø ] Â. r : ½ ¨\ " f H¿ º> h_ " f Ð r É æ ×d

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(122) Ä 3 »Y Us $ _ ½ ¨ ³s & 0 x½ p É + Ü ‫כ‬ ¼ Ðl @ / a ) .. [1] D. Huang, E. A. Swanson, C. P. Lin, J. S. Schuman, W. G. Stinson, W. Chang, M. R. Hee, T. Flotte, K.Gregory, C. A. Puliafito and J. G. Fujimoto, Science 254, 1178 (1991). [2] B. Bouma, G. J. Tearney, S. A. Boppart, M. R. Hee, M. E. Brezinski and J. G. Fujimoto, Opt. Lett. 20, 1486 (1995). [3] J. M. Schmitt, IEEE J. Sel. Top. Quantum Electron. 5, 1205 (1999). [4] A. F. Fercher, W. Drexler, C. K. Hitzenberger and T. Lasser, Rep. Prog. Phys. 66, 239 (2003). [5] S. Yun, G. Tearney, B. Bouma, B. Park and J. de Boer, Opt. Express 11, 3598 (2003). [6] S. H. Yun, C. Boudoux, G. J. Tearney and B. E. Bouma, Opt. Lett. 28, 1981 (2003). [7] N. Nassif, B. Cense, B. H. Park, S. H. Yun, T. C. Chen, B. E. Bouma, G. J. Tearney and J. F. de Boer, Opt. Lett. 29, 480 (2004). [8] R. Leitgeb, C. K. Hitzenberger and A. F. Fercher, Opt. Express 11, 889 (2003). [9] J. F. de Boer, B. Cense, B. H. Park, M. C. Pierce, G. J. Tearney and B. E. Bouma, Opt. Lett. 28, 2067 (2003). [10] W. Y. Oh, S. H. Yun, G. T. Tearney and B. E. Bouma, IEEE Photon. Technology Lett. 17, 678 (2005). [11] T. J. Eom, B.-A. Yu, W. Shin, Y. L. Lee, C.-S. Kee, D.-K. Ko, J. S. Park, E. J. Jung, C.-S. Kim and M. Y. Jeong, Proceedings of the OSK Annual Meeting 2007, T2F-v12 (Gwangju, 2007). [12] J. Zhang, M. Y. Jeon, Z. Chen, Proceedings of SPIE Photonics West 2008, Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine (California, 2008)..

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(124) Ä 3 »Y Us $ \ ¦s 6 xô Ç· · · – % I 3 × æ1 x p. -443-. Time-encoded Frequency-domain OCT by Using a Wavelength-swept Fiber Laser with a Dual-cavity Structure T. J. Eom,∗ Y. L. Lee, B-A. Yu, G. S. Yun and J. Lee Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 500-712 E. J. Jung, M. Y. Jeong and C-S. Kim Department of Nanosystem Engineering, Pusan National University, Busan 609-735 (Received 8 April 2008). We have developed a wavelength-swept fiber laser by using semiconductor optical amplifiers with different center wavelengths. The wavelength-swept laser can be utilized as a broadband source for a frequency-domain Optical Coherence Tomography (OCT) system. The wavelength-swept fiber laser was constructed with a dual cavity. Each laser having an identical cavity structure was governed by different lasing conditions, which resulted in a reduced insertion loss for the laser cavity. The two semiconductor optical amplifiers had the same gain bandwidth of 40 nm. The dual-cavity fiber laser had a 0.1-nm instantaneous spectral linewidth and a 1.2-mW average output power at wavelength of 1320 nm. The time-encoded Fourier domain OCT system with a dual cavity was used to image a rat eye and showed potential for application to biological imaging. PACS numbers: 42.30.Wb Keywords: Wavelength tunable source, Semiconductor optical amplifier, Optical coherence tomography, Biological imaging. ∗ E-mail:. [email protected].

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7 H  Sae Mulli (The Korean Physical Society), Volume 56, Number 5, 2008&cedil

7 H Sae Mulli (The Korean Physical Society), Volume 56, Number 5, 2008&cedil