| 摘要 |
PURPOSE: To avoid defective reception due to ununiform oscillated output level and oscillated wavelength between plural modulation waves by preventing the increase in a light source attended with the increased number of signal waves without reduction in an output intensity even when a single mode fiber is employed for an optical fiber. CONSTITUTION: A 1st electrooptic modulation section 32 multiplexes a carrier outputted from an LD light source 31 by multiplex signals M3, M4 outputted from a 1st multiplexer section 34. A 2nd electrooptic modulation section 33 modulates the output of the 1st electrooptic modulation section 32 with multiplex signals M1, M2 outputted from a 2nd multiplexer section 35. The multiplexed signals M3, M4 and the multiplexed signals M1, M2 are synchronized by a synchronizing signal generating section 36 and outputted without being overlappingly outputted. Thus, the 2nd electrooptic modulation section 33 provides the output of a modulation wave by the multiplexed signals M3, M4 and a modulation wave by the multiplexed signals M1, M2 in time division. |
