| 摘要 |
PURPOSE:To improve stability and linearity against the change of incidence conditions by providing stress giving parts which face each other across cores in a clad wherein the cores are embedded. CONSTITUTION:The couple of cores 13 and 13 are embedded in the clad 12 and the couple of nearly circular stress giving parts 14 and 14 are formed across said cores 13 and 13. The shape, etc., of the clads 12 is not limited specially and the number of the cores 13 is preferably two, but >=3 cores are allowed; and the shape, number, etc., of the stress giving parts 14 are not limited specially as long as they stress the cores 13. The stability to the change of the incidence conditions, etc., and the polarization characteristics as a dual core type single mode optical fiber are improved greatly through the double refraction caused by the core parts by the stress giving parts 14. Consequently, the stability to the change of the incidence conditions, etc., is excellent and the sensor optical fiber which has high reliability as to the linearity is obtained. |
