| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problems that a transmission band is narrow and a cost is high though an external modulation type optical transmitter is suitable for a large-scale multiple distribution and a long-range transmission, and there is the influence of wavelength dispersion due to a chirping phenomenon, the quality of video signals is degraded and a transmission distance is constrained while a direct luminance modulation type optical transmitter is capable of wide band transmission. <P>SOLUTION: This optical transmitter of a direct luminance modulation type using a laser diode for oscillating the narrow light beam width laser of 1.55 μm band, detects the entire power of RF signals inputted to the optical transmitter, adjusts an optical signal level to be inputted to the laser diode on the basis of the detected level, and controls the optical modulation degree of direct luminance modulation. The optical signal level is set such that the laser oscillated from the laser diode has a narrow light beam width having a chirp suitable for suppressing the generation of SBS. <P>COPYRIGHT: (C)2007,JPO&INPIT |
