| 摘要 |
PURPOSE:To facilitate fine positioning while an external shape is rectangular by forming one line or lines of variation layers having a large index of refraction on the surface of a substrate in an arc shape and in the thickness direction from the plane part. CONSTITUTION:On the top surface 11 of a soda glass substrate 1, a metallic mask for exposing thin lines 21 is formed by vapor deposition, sputtering, etc., and in dissolved slat which contains Tl<+>, Ag<+>, Li<+>, K<+>, etc., the substrate is dipped to substitute Na<+> ions for metallic ions, thereby forming variation layers whose index of refraction decreases continuously to that of the substrate 1 like arcs 22 having chords equal to the width of the thin line 21. Thus, a cylindrical lens having an index of refraction 0.003 greater than, for example, the substrate 1 is manufacture. On the reverse surface 12 of the substrate 1, lenses 3 crossing said cylindrical lenses 2 at right angles are formed by a similar method. Intersections of the lenses 2 and 3 are combined lenses, which are used as coupling devices for optical fibers. |
