| 摘要 |
<p>PROBLEM TO BE SOLVED: To achieve a mode exchange which targets three or more of optical signals having different modes from each other and has excellent efficiency.SOLUTION: Means having a bypass path 12 for bypassing optical signals out of the subject of mode exchange from an input end to an output end of a mode exchanging switch 11 by the mode exchanging switch is cascade connected in a plurality of stages to the mode exchanging switch capable of making operation replacing modes with each other on/off by converting respective modes of two optical signals having different modes from each other.</p> |
