| 摘要 |
PROBLEM TO BE SOLVED: To provide a burst optical transmitter capable of applying APC (automatic power control) system and obtaining instantaneous responsiveness for the burst optical transmitter of a direct modulation system. SOLUTION: For this burst optical transmitter during the generation of burst input signals, the burst input signals are sent via a selector 3 to an LD(laser diode) driver circuit 2, and an LD 1 is directly modulated and burst signal light is generated. The burst signal light is made to pass through a light switch 7 and transmitted to the outside, a part of it is received by a PD 5 and sent to an APC circuit 6, and the output light power of the LD 1 is controlled to be fixed. In the meantime when the burst input signals are interrupted, signals generated in a random pattern generator 4 are sent through the selector 3 to the LD driver circuit 2, the drive of the LD 1 is maintained and the control of the APC circuit 6 is performed continuously without interruption. Also the transmission of laser beams generated during the time is blocked by the light switch 7. |
