| 摘要 |
PURPOSE:To make setting and controlling easy and make the attenuator manufacturable inexpensively and easily by forming the reflecting surface to be formed on a substrate at reflectances varied as desired and making the arbitrary reflecting surfaces freely movable on the optical guide optical axis, with respect to the light attenuator of a transmission system using optical fibers. CONSTITUTION:A pattern 13 of shelf-shaped piece surfaces, a pattern 14 of rectangular-strip-piece-shaped surfaces, a pattern 15 of piece-shaped surface arranged in a checkered shape and a pattern 16 of piece-shaped surface of small circles are respectively formed on the surfaces above the center 7 of the disc-like base plate 10 at arbitrary distances apart from the center 7, and the reflecting surfaces formed by these patterns and the surface of the base plate are so determined as to assume respectively desired reflectances. The pattern surfaces of this base plate 10 are positioned on the insecting point C of the optical axes A and B and are rotated around the center 7 by rotating means whereby the arbitrary patterns may be positioned on the optical axis. This makes it possible to rotate the substrate 10 in order to attenuate the light signal 3 to the desired level 3' and to control the extent of attenuation of the light signal stagewise. |
