| 摘要 |
<p>If an optical switch unit configuring an optical switch is implemented by a three-stage circuit, optical amplifiers are arranged on the input and output sides of an optical space switch in a first stage, and the optical space switch and the optical amplifiers on both of the input and output sides are used as an expansion unit for expanding a switching capacity. Similarly, optical amplifiers are arranged on input and output sides of an optical space switch in a third stage, and the optical space switch and the optical amplifiers on both of the input and output sides are used as an expansion unit for expanding a switching capacity. Accordingly, there is no need to arrange extra optical amplifiers even at an initial setting when only part of a maximum switching capacity is used, thereby reducing an initial investment. <IMAGE></p> |
