| 摘要 |
PURPOSE:To restrain the eye deterioration and decrease the relaxation oscillation so as to stablize a spectrum, where the eye deterioration and the relaxation oscillation are caused by a pattern effect of a spectrum and a wavelength dispersion property of an optical fiber of the an optical fiber transmission, by a method wherein a voltage composed of a specified direct current voltage and a discharge and charge voltage added to it is applied to a laser diode as a bias voltage. CONSTITUTION:A condenser of a discharge and charge means 50 is charged with a voltage which is corresponding to inverted '1' when an input data, for example, is '0' and a switching means 30 is OFF by adding a data of an input data inverted by the switching means 30 to a charge and discharge means 50. On the other hand, the switching means 30 is ON when an input. data is '1', then a voltage charged in a condenser is discharged through the intermediary of the switching means 30. A voltage charged in the condenser is applied to an additing means 40 with a specified direct current voltage to be added together, which is impressed on a laser diode 10 through the intermediary of a coil L. In result, when an input data applied to a gate of a field effect transistor continues to be '0', an eye deterioration caused by a pattern effect of a laser diode output waveform can be restrained within such an extent that a quenching ratio is made not to be deteriorated. |
