| 摘要 |
PROBLEM TO BE SOLVED: To provide an interpulse phase difference measuring method which has a sufficient sensitivity even to general optical combs, has high precision, is provided with a calibration means, and ensures precision. SOLUTION: In this interpulse phase difference measuring method, an optical pulse train to be measured is branched into two luminous fluxes, and one of these branched fluxes is transmitted through a first optical path, and the other is transmitted through a second optical path. The relative delay time difference between the first and second optical paths is set to a vicinity of the cycle period of the optical pulse train. The phase difference between pulses in the optical pulse train is measured, by combining the light transmitted through the first optical path and the light transmitted through the second optical path and causing them to interfere. The length of the second optical path is variable, and changing the length of the second optical path, the intensity of each interference light obtained by combining light waves is serially recorded. A row of the above recorded intensity data is Fourier-transformed. Obtained phases in frequency ranges are extraporated, and from the value of a found phase at zero frequency, the phase difference between the phases is measured. COPYRIGHT: (C)2004,JPO
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