| 摘要 |
PURPOSE:To stably transmit and supply circularly polarized light even by a transmission line having a bent part and a narrow part, etc. by connecting a single polarized wave fiber for only propagating an only polarized wave mode and a double refractive index fiber by inclining each intrinsic polarization axis by 45 deg., and also, specifying the length of the double refractive index fiber. CONSTITUTION:A circularly polarized light optical transmission line is formed by connecting a single polarized wave fiber 4 and a double refractive index fiber 5 of a single mode by a welding and connecting part 6 by inclining each intrinsic polarization axis by 45 deg.. Accordingly, a single polarized wave mode which is propagated through a single polarized wave fiber 4 is coupled to the double refractive index fiber 5, and in the fiber 5, two orthogonal polarized wave modes are excited by an equal phase, and a polarization state is varied in the longitudinal direction. Coupling length (beat length) L of the double refractive index fiber 5 is shown by L=lambda/B, when the double refractive index and the wavelength are denoted as B and lambda, respectively. In such a state, by adjusting the fiber length of the double refractive index fiber 5 to mL+ or -L/4 (m is an integer), an emitted of the double refractive index fiber 5 goes to circularly polarized light. In such a way, the circularly polarized light can be supplied easily and stably to an arbitrary place such as a narrow part, a bent part, etc. |
