Patent ID: 6901174

Claim:
A device for multiplication of repetition frequency in optical pulse trains composed of optical fibres, an optical amplifier and a modulator for optical modulation, and an electric signal generator generating high frequency signals, comprising: wherein, the modulator makes an optical pulse train of repeating frequency of f m , when applying electric signals of frequency of f m to the modulator; and a filter which can pass integer multiple frequencies of the applied modulation frequency f m , and a composite cavity composed of a plurality of optical fibres of which lengths are different from each other; wherein as a resonant frequency f c1 of the fibre ring of the long cavity of the composite cavity and a resonant frequency f c2 of the fibre ring of the short cavity of the composite cavity, a lowest common multiple frequency ⁢ f composite ′ of f c1 and f c2 , and as frequency K×f m (K:integer) which passes through the filter, the frequency ⁢ f composite ′ is integer multiple of K×f m , and the repetition frequencies of the generated optical pulses are P×K×f m (P: integer.).