| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pulse measuring device which accurately evaluate a time width and coherence time of an optical pulse independently without missing such features that a wavelength of the optical pulse is not limited and time characteristics of a weak optical pulse can be evaluated. SOLUTION: An optical circuit 11 converts an optical pulse 21 to be measured into a train-of-four optical pulse 22 comprising two consecutive double optical pulses which are coherent to each other and have a time interval of T<SB>0</SB>+ΔT, wherein positions of the center of gravity of the respective double optical pulses are separate from each other by 2cT<SB>0</SB>and the respective double optical pulses are incoherent to each other, and emits the pulse. An asymmetric Mach-Zehnder interference optical circuit 12 splits the train-of-four optical pulse 22 into two light paths with their light path lengths differing by cT<SB>0</SB>, causes the train-of-four optical pulses 22 in the respective light paths to interfere to generate train-of-five optical pulses 23, splits and emits them. An evaluation part 13 measures light intensity of each train-of-five optical pulse 23, and independently evaluates a time width and coherent time of the optical pulse 21 to be measured based on the light intensity. COPYRIGHT: (C)2011,JPO&INPIT
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