OPTICAL FIBER WITH CONSTANT POLARIZATION

摘要

PURPOSE:To easily decide a fiber axis from outside by providing a tensile force holding part made of glass which has high softening point temperature and a low refractive index at a position off the center of the section in a clad layer. CONSTITUTION:The tensile force holding part 4 is off the center of the section in the clad layer 2 and a layer made of glass which has the higher softening point temperature than glass for a core 1, glass for a clad 2, and glass for strain inducing parts 3a and 3b and has the lower refractive index than the glass for the clad 2. Consequently, the constant polarization optical fiber has the excellent polarization holding ability and the axis of birefringence is easily decided even visually from outside.