| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical loss detection device for improving the accuracy in optical loss detection and improving the optical transmission quality. <P>SOLUTION: A correction level calculation portion 11 computes a correction level Pc required for satisfying a light to noise ratio when optical noise is maximum. An optical loss detection threshold setting portion 12 compares the correction level Pc with an initial threshold level Tdef, and sets an optical loss detection threshold Th for detecting optical loss, based on the result of the comparison. An optical loss detection unit 13 compares an input level of an optical signal in operation with a level of the optical loss detection threshold Th. When the input level is smaller than the optical loss detection threshold Th, it is determined that optical loss occurs. The optical loss detection threshold setting portion 12 sets the correction level Pc as the optical loss detection threshold Th when the correction level Pc is larger than the initial threshold Tdef, while setting the initial threshold Tdef as the optical loss detection threshold Th when the correction level Pc is smaller than the initial threshold Tdef. <P>COPYRIGHT: (C)2009,JPO&INPIT |
