| 摘要 |
PURPOSE:To improve the high frequency characteristics of an LD modulating circuit by connecting at least >=1 diode in series to an inductance connected in parallel to a semiconductor laser. CONSTITUTION:A modulated signal is inputted to the base of a transistor (TR)4, and a semiconductor laser 7 is connected to the collector of the TR4. For this purpose, a series circuit of diodes 41 and 42 and an inductance 8 is connected in parallel to the laser 7. Then, the DC bias of the laser 7 is prevented from flowing to the inductance 8 by the bias voltages of the diodes 41 and 42. Further, the differential resistances of the diodes 41 and 42 are small, so a load viewed from the laser 7 is only the inductance 8. Consequently, the high frequency side of the modulating circuit of the laser 7 is improved. |
