| 摘要 |
PURPOSE:To make a mode scrambler small-sized and to reduce a speckle noise, by providing a core diameter expansion part on a multimode optical fiber. CONSTITUTION:When a core diameter expansion part, which has been formed in a convex part 10 which is almost symmetrical to a fiber axis or in an asymmetrical convex part 10', and which has a radius of curvature which is 2-3 times as large as a radius of a core 9, is provided on a part of a multimode optical fiber 8, a light beam of plural modes, which has been transmitted into the optical fiber and is capable of interference, is reflected and stirred by the curved surface of the core in this core diameter expansion part, and is dispersed to much more modes, and mode mixing is executed. This core diameter expansion part is formed by equally heating a prescribed area of the optical fiber 8 to a high temperature from the surrounding part by means of electric discharge heating, etc., and by putting force in the axial direction of the optical fiber to the heating area from both sides of the heating area. |
