| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarization retention photonic crystal fiber (polarization retention PCF) whose connection loss can be maintained low even when the polarization retention PCF is connected to another optical fiber and to provide its fiber edge working method. SOLUTION: In a cross-sectional surface of the fiber, only a pair of fine holes 13b of three pairs of fine holes opposed to each other across a core 11 are formed so as to have a diameter larger than that of the other fine holes 13a and thereby an optical transmission region of the core 11 is made to be elliptical. The polarization retention PCF 10 with a circular high refractive index part transmits light having elliptical mode distribution by the influence of the fine holes 13a and 13b anisotropically existing in a clad 12 even though the polarization retention PCF has a circular high refractive index portion 14 formed of a material showing no birefringence. When the end part is heated by arc discharge or the like, the fine holes 13a and 13b are sealed, and the mode distribution of light passing through the end surface is made circular. COPYRIGHT: (C)2005,JPO&NCIPI |
