| 摘要 |
PURPOSE: To make it possible to obtain a wide band width by measuring a pair of refraction factor profiles from one symmetrical axis of an optical fiber through a plane polarized beam, which has a refraction factor recessed along one symmetrical axis and is made parallel or vertical to a selected symmetrical axis, and specifying a parameter calculated from these profiles. CONSTITUTION: A pair of refraction factor profiles, which are measured by the plane polarized beam made parallel or vertical to the selected symmetrical axis, from one symmetrical axis of an optical fiber 10 are considered, and a parameterηis calculated from te respective profiles by an equality I. In the equality I, n (r) shows the refraction factor at a radiation position (r) measured along the symmetrical axis from one of two polarizing directions of the beam and nc1 shows the average refraction factor of a clad over the distance from four times to seven times as long as a core radius from the center of a core 12. At the time of calculation from the refraction factor profile determined by one of two azimuths of polarized beam, theηis positive for one symmetrical axis and at the time of calculation from the refraction factor profile determined by the orthogonal direction of the polarized beam, theηis negative. Thus, by winding a coil while having satisfactory band width, light can be polarized by a much shorter fiber. |
