| 摘要 |
PURPOSE:To attain the optical PLL circuit with high speed operation with simple constitution by varying the amplification factor of light proportional to the intensity of an electric signal applied to an optical amplifier. CONSTITUTION:The amplification factor of light is varied proportional to the intensity of an electric signal applied to the optical amplifier 202. A photodetector 203 outputs all electric signal at a sufficiently low speed with a frequency DELTAf corresponding to the frequency difference of the both, an excess frequency component is eliminated except frequencies DELTAt by a band pass filter 204 and the output voltage of a frequency discriminator 205 is changed in response to the frequency change of the input signal. Thus, when there is any fluctuation in the repeat frequency f0 of a signal optical pulse, a fluctuation takes place in the DELTAf component, an output voltage change is caused in response to the fluctuation. The output voltage is applied to a voltage controlled oscillator(VCO) 206 to control the oscillating frequency of the VOC 206 to make the frequency equal to the repeat frequency f0 of the input light pulse Thus, the optical pulse with the same repeat frequency f0 as the repeat frequency f0 of the input signal pulse is outputted from a clock optical pulse generating section 211. |
