| 摘要 |
PURPOSE: To provide a compact and simple optical communication system which improves its linearity and is suitably applied to the comparatively high frequency by producing the pre-compensation signals of opposite phases via the combination of an impedance element of proper value and a diode. CONSTITUTION: A capacitor 38 limits the current flowing through a solid state laser 42, and a resistance 22 secures the matching between the input impedance of an optical transmitter 8 and the output impedance of a signal voltage source. The degrees of pre-compensation can be set by a resistance 32. The voltage level rises between the 1st and 2nd terminals of a linearization device 25 like the rise of the input voltage level of the transmitter 8. A diode 30 is biased in the direction opposite to the direction of voltage change covering the device 25 and accordingly the voltage level covering the diode 30 is lowered. As a result, the impedance of the diode 30 increases and accordingly the overall impedance of the device 25 also increases. Thus, the voltage of the device 25 rises in a more proportional way and accordingly the voltage of the laser 42 rises with proportionality lower than that of the device 25. Such a compensating way is suitably applied to the nonlinearity of the super-linear solid state laser 42. |
