| 摘要 |
PURPOSE:To set the diameter of a beam to optional size, by constituting so that a light beam which has been made incident at a suitable incident angle to spherical mirrors being conjugate to each other and disposed as a group is reflected between the spherical mirros and makes one common focus. CONSTITUTION:This optical waveguide is provided with a group of spherical mirrors by which at least 2 concave spherical mirrors or at least 2 convex spherical mirrors have been placed at a twist position Tw. Also, as the case may be, it contains a group of spherical mirros by which at least 1 convex spherical mirror and at least 1 concave spherical mirror have been placed at a position Lw where a normal set in the center ''0'' of the mirror surface is on the same plane containing the optical axis. A light beam which has been made incident at a suitable incident angle to the spherical mirrors of these groups is reflected by the spherical mirrors so as to make one common focus F. |
