OPTICAL FIBER TYPE OPTICAL PART AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To provide an optical fiber-type optical part which has a coating with decreased absorption of light and in which generation of multimode propagation is suppressed, and to provide the producing method. SOLUTION: A coating part 3 comprising a thermosetting silicone having high transmittance for UV rays is formed on the peripheral face of an optical fiber 10 consisting of a core 1 and a clad 2 to obtain a coated optical fiber 20. By this method, a pattern having changes in the refractive index can be efficiently produced by radiation of UV rays in the production process of the optical fiber-type optical parts. The refractive index of the coating 3 is usually lower than that of the clad 2, but by constituting the clad 2 of a first clad 2a and a second clad 2b having a higher refractive index than that of the first clad 2a, propagation of high-order modes produced can be suppressed.