| 摘要 |
PROBLEM TO BE SOLVED: To set an optical transmission power and an extinction ratio, by suppressing deterioration of extinction ratio due to influence of aging when transmitting a signal from a plurality of optical network units (ONU) to an OLT in a PON system housing an ONU.SOLUTION: An optical network unit (ONU) detects average power in a preamble section and a data section during burst transmission, and detects the "0" level even in the laser off time. A modulation current is set by using an average power thus detected, and then a bias current is set using the "0" level thus setting an optical transmission power and an extinction ratio. |
