| 摘要 |
PURPOSE:To eliminate the danger owing to the leakage of light from a clad by providing an exposed part removed of the clad in the end part of a core which propagates a laser for medical treatments or the like and is coated with the clad of a refractive index smaller than that of the core thereby forming a scattering surface. CONSTITUTION:An optical transmission device 1 is constituted by coating the outside circumferential surface of a core 2 with a clad 3 of a refractive index smaller than that of the core 2 and further coating the outside circumferential surface of the clad 3 with a resin cover 4. One end part of the core 2, that is, the end part lg to which a laser L is made incident is removed of the clad 3 and is formed to an exposed part 5. The outside circumferential surface of the part 5 is subjected to, for example, a satin treatment by which said part is formed to a scattering surface 6. The end part of the clad 3 continuous to the part 5 is removed of the cover 4 for a prescribed length and is formed similarly to a scattering surface 7. Thus the numerical aperture of the light propagating in the core can be made smaller than the numerical aperture determined by the refractive indices of the core and the clad. Therefore, even when the device 1 is used by bending the same, the leakage of the light from said part is virtually eliminated. |
