Environmental characteristic measuring device and environmental characteristic measuring method

摘要

To provide an environment characteristic measuring device and an environment characteristic measuring method, in Brillouin optical sensing technology, for measuring Brillouin gain using a few-mode optical fiber accurately even when mode conversion-mode coupling occurs.SOLUTION: Provided is an environment characteristic measuring device for analyzing Brillouin frequency shift using a few-mode optical fiber, in which multiple modes are multiplexed, as a measuring optical fiber F, said device comprising: means for inputting probe light of a desired mode from a far end of the measuring optical fiber F; means for inputting, to the probe light, an optical pulse as a pump light pulse having a frequency difference equivalent to the Brillouin frequency shift of the measuring optical fiber F on the high frequency side; and means for inputting, from a near end of the measuring optical fiber F to the probe light, a second probe light in another mode different from the desired mode and having a frequency difference equivalent to the Brillouin frequency shift of the measuring optical fiber F on the low frequency side.SELECTED DRAWING: Figure 1