| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical transmitter capable of performing long-distance transmission like the conventional low chirp directly modulated laser and capable of simplifying the configuration and reducing a production cost and size in comparison with the conventional low chirp directly modulated laser. SOLUTION: The optical transmitter includes a directly modulated laser 2 and a wavelength filter 3 provided to the post-stage of the directly modulated laser 2. The wavelength filter 3 has a modulated light input port 3A for entering modulated light output from the directly modulated laser 2, a filter transmitted light output port 3B for outputting light having a wavelength included in a filter transmission band among the input modulated light as filter transmitted light, and a filter cutoff light output port 3C provided separately from the modulated light input port 3A and the filter transmitted light output port 3B, for outputting light having a wavelength included in a filter cutoff band among the modulated light as filter cutoff light, and the peak of the filter transmission band is set on a shorter-wave side from the peak of the spectrum of modulated light output from the directly modulated laser. COPYRIGHT: (C)2007,JPO&INPIT |
