| 摘要 |
PROBLEM TO BE SOLVED: To provide a phase modulation device in which each component is not required to be assembled while equalizing the length, and skew adjustment is facilitated even if the temperature characteristics of components changes or secular change of components takes place.SOLUTION: A phase modulation device 301 comprises a light source 10 outputting continuous light, an RZ phase modulation circuit 101 having two phase modulators 12 and an intensity modulator 15, where the phase modulators 12 perform phase modulation of the continuous light from the light source 10 with data signals (DATA 1, 2) input respectively thus generating two phase modulation optical signals, a phase shifter 13 shifts the phase of one phase modulation optical signal by &pgr;/2, and the intensity modulator 15 outputs a multiplexed signal of one phase-shifted phase modulation optical signal and the other phase modulation optical signal while performing intensity modulation and RZ modulation with an input clock signal CLK, and a phase control circuit 111 which adjusts the phase of the phase modulation optical signals generated by the phase modulators 12 of an RZ phase modulation circuit 101, respectively, so as to maximize the output therefrom. |
