| 摘要 |
PURPOSE:To facilitate the construction of the titled device by adding digital signals to a high pass processing means and a low pass one and then synthesizing the signal component of each band with a DC bias current. CONSTITUTION:The digital input signal 1 inputted to an input terminal 1' is divided into two bands by a high pass filter 7 and a low pass filter 8, each of which is then fed to an LD (semiconductor laser) high pass driving part 9 and an LD low pass driving part 10. The signal of each band is amplified in both the driving parts 9 and 10 and fed to a synthesizing part 11. the synthesizing part 11 adds the signal from a DC bias part 4 to that from both the driving parts 9 and 10, thus driving the LD. Thus, LD drive over a wide band is enabled by simple driving parts. |
