| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a control system in which the phase shift between drive signals of an optical modulator can be reliably detected and compensated by a simple configuration. <P>SOLUTION: A control apparatus of the invention, for an optical modulator generating a signal light of a CS-RZ modulation system or the like by two LN modulators 10 and 20 connected in series, detects, by a phase comparator 30, the phase shift between drive signals given to the former and latter stage LN modulators 10 and 20, or determines the phase shift between the drive signals based on intensity information on the electric spectrum of the signal light outputted from the optical modulator, to control the phases of the drive signals so as to minimize the phase shift. As a result, the phase shift between the drive signals can be reliably detected and compensated by an electric circuit with a simple configuration. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
