| 摘要 |
PROBLEM TO BE SOLVED: To provide a monitoring device or a monitoring method for accurately controlling an optical modulator. SOLUTION: An external modulator monitoring device includes: a mixing unit mixing an optical signal modulated by an external modulator with an optical signal not modulated by the external modulator to obtain a plurality of mixed optical signals; an electric differentiating unit converting the plurality of mixed optical signals into a plurality of corresponding electric signals and obtaining a voltage difference of the plurality of electric signals to obtain a difference signal; and a power detecting unit detecting the power of the difference signal. COPYRIGHT: (C)2011,JPO&INPIT |
