Optical fiber for preserving plane of polarization

摘要

An optical fiber for preserving the plane of polarization (4) including a cladding (2) and a stress imparting part (3) disposed in the cladding, the stress imparting part comprising a base material including B2O3. The average concentration of B2O3 in the base material of the stress imparting part is in a range between about 17 and 21 wt.%, and the maximum concentration of B2O3 in the base material is in a range between about 17 and 22 wt.%. The optical fiber has excellent polarization plane preserving properties, and no concave portion is generated in its stress imparting part even under wet heat conditions.