| 摘要 |
PURPOSE:To present an optical fiber having a satisfactory polarization keeping characteristic by providing two intermediate members, which are brought into contact with the core and are arranged in the diametral direction of the fiber, and two stress giving parts which are brought into contact with these intermediate members and are arranged in the diametral direction. CONSTITUTION:Since side bits 4 are provided on both sides of a core 1 of this optical fiber, the refractive index on the outside of the core is lower than that of the clad in the direction of the X axis, and the refractive index distribution is very anisotropic even in the vicinity of the core. Therefore, birefringence due to anisotropy of the refractive index part is obtained in this optical fiber, and birefringence more powerful than a conventional polarization keeping optical fiber is obtained by synergistic effect of this birefringence and birefringence due to the stress from stress giving parts 3. Consequently, the optical fiber having the satisfactory polarization keeping characteristic is obtained because a high birefringence index is obtained without concentrating the stress, which is excessive to deform the core or cause irregularity on the boundary surface between the core and the clad, to the vicinity of the core. |
