PROBLEM TO BE SOLVED: To provide an optical frequency domain reflection measuring method capable of detecting a distortion change within a short time, an optical frequency domain reflection measuring device, and an apparatus for measuring a position or a shape using the same.SOLUTION: A polarization multiplexing section 10 generates a light by multiplexing lights in first and second polarization states of polarization waves orthogonal with each other with a shorter predetermined time difference than a time for light reciprocation by a fiber Bragg diffraction grating. The generated light is given as a measuring light Pmes to an optical fiber 37 to be measured including the fiber Bragg diffraction grating of which the grating interval is chirped. In a signal processing section 101, Fourier transform processing on digital signals Ds and Dp which are obtained by one time of wavelength sweeping, is performed while being divided in a plurality of terms where beat frequencies generated by interference between reflection lights from the optical fiber 37 to be measured with respect to the lights in the first and second polarization states, and a reference light are not overlapped. Fourier transform results are combined on a distance axis, and properties of the optical fiber to be measured with respect to the lights in the first and second polarization states are calculated.COPYRIGHT: (C)2016,JPO&INPIT【課題】短時間に歪み変化の検出を可能にする光周波数領域反射測定方法、光周波数領域反射測定装置およびそれを用いた位置または形状を測定する装置を提供する。【解決手段】格子間隔がチャープしたファイバブラッグ回折格子を有する被測定光ファイバ37に対し、互いに偏波が直交する第1、第2の偏波状態の光が、ファイバブラッグ回折格子を光が往復する時間より短い所定の時間差をもって合波された光を偏波多重部10で生成して測定光Pmesとして与え、信号処理部101において、1回の波長掃引で得られたディジタル信号Ds、Dpに対するフーリエ変換処理を、第1、第2の偏波状態の光に対する被測定光ファイバ37からのそれぞれの反射光と基準光との干渉によって生じるビート周波数が重ならない複数の期間に分割して行ない、そのフーリエ変換結果を距離軸上で合成して、第1、第2の偏波状態の光に対する被測定光ファイバの特性を求める。【選択図】図1
