| 摘要 |
<p>An undesired ASE generated in optical communication is reduced so as to increase the transmission distance span. A carbon nano tube is used as a saturable absorber (15). The saturable absorber is inserted in the path of the signal light of, for example, bidirectional excitation type EDFA (50) such as in the latter stage of the EDF (40), so as to serve as a noise reduction apparatus for cutting off or reducing an undesired ASE having a weak signal light intensity and transmitting a signal light having a strong light intensity. The noise reduction apparatus can be used in the field of the optical communication using a carbon nano tube having the saturable absorption function.</p> |
