| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical add/drop switch including a large number of optical paths which is approximately uniform and of a low loss by the minimum number of switching structures. SOLUTION: Optical switches (100, 186) comprise a first optical paths (144, 146, 148, 150) and a second optical paths (152, 156, 158) which form arrays and cross each other. At the position where a loss of the signal light can be made uniform among the predetermined crossing points at the optical paths cross, two-condition switching structures (102, 104, 106 and 108; 188, 190, 192 and 194) which can realize a transparent condition or reflective condition selectively are arranged selectively so as to be single for each optical path. The single switching structure is formed as a single-body switching structure (102, 104, 106 and 108) or a tandem-type switching structure (188, 190, 192 and 194) which is interlocked with each other. |
