Bandpass filter and 2 counting-down circuits and the amplifier of the optical directional coupler

摘要

PROBLEM TO BE SOLVED: To provide an optical and electric frequency division clock generator, an optical clock frequency division apparatus operable for the input of optical signals not including frequency division components, an optical and electric frequency division clock extraction apparatus, an optical time division demultiplexing apparatus, an optical frequency division clock extraction and optical data serial/parallel conversion apparatus, and an optical modulation format conversion apparatus.;SOLUTION: As a basic configuration, a photoelectronic oscillator in the configuration of arranging a frequency divider inside a closed loop positive feedback circuit is used. In the figure 1, a 2^N frequency divider 7 includes a function of frequency-dividing the frequency of signals into 1/2^N that a conventional photoelectronic oscillator does not have, and converts the signals of a frequency f₀ which pass through a band-pass filter 6 to the signals of a frequency f₀/2^N. Since an optical intensity modulator 2 is driven by the signals of the frequency f0/2^N, the optical clock signals of the frequency f₀/2^N and the electric clock signals of the frequency f₀/2^N are simultaneously generated.;COPYRIGHT: (C)2009,JPO&INPIT