| 摘要 |
PURPOSE: To obtain a variable light attenuation device which can control the attenuation quantity of light intensity continuously and is small in size and inexpensive by deforming an optical fiber from a nearly circular state to a non-circular state and controlling the attenuation quantity of light passing through an optical fiber. CONSTITUTION: A support member 20 is composed of a thin steel-made tape 23 and a horseshoe type spring 15 and is flexible. The optical fiber 24 which is supported nearly circularly by the support member 20 is deformed by a control means from the nearly circular state to the noncircular shape. At this deformed part, the light propagated in the optical fiber 24 is attenuated. Further, precise control is performed so that the radius of curvature of the optical fiber 24 supported while curved nearly circularly is smaller than a predetermined limit value. Then the optical fiber 24 also deforms, so the light of the fiber core is leaked out without breaking or deteriorating the optical fiber 24 or a signal passing through the optical fiber 24, thereby attenuating the light propagates in the optical fiber 24. |
