Tatsuya KINJO, Yoshinori NAMIHIRA, Kazuya ARAKAKI, Shubi F. KAIJAGE, S. M. Abdur RAZZAK, Feroza BEGUM, Hiroki HIGA, Shinya NOZAKI¹, and Nianyu ZOU²

Graduate School of Engineering and Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
¹Transdisciplinary Research Organization for Subtropical and Island Studies University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
²Research Institute of Photonics, Dalian Polytechnic University, No. 1 Qinggongyuan, Ganjingzi Dist, Dalian 116034, China

(Received July 27, 2009; Accepted January 12, 2010)

In this paper we present the design of a modified hexagonal photonic crystal fiber (PCF) having high birefringence and a near-zero flattened dispersion. Using the finite-difference method (FDM), it is shown that the proposed multiple Ge-doped core hexagonal PCF exhibits a high birefringence of order 10^-3 and a nearly zero flattened dispersion in the optical coherence tomography (OCT) waveband. In addition, the proposed PCF has a confinement loss of less than 10^-8 dB/m at 1.06 μm. PCFs with such properties are considered suitable for both endoscopic OCT and other experimental setups employing 1.06 μm lasers.

Key words: photonic crystal fiber (PCF), birefringence (B), dispersion (D), confinement loss (L_C), optical coherence tomography (OCT), finite difference method (FDM)