PROBLEM TO BE SOLVED: To propose a new approach to identify an original magnetic field situated within a measurement region.SOLUTION: A light source unit 2 radiates linear polarization light of which the travel direction is a z-axis direction and the vibration direction of the magnetic field is a y-axis direction to a gas cell 3 arranged in a measurement region. A polarimeter 4 detects optical characteristics of light that has passed through the gas cell 3. A magnetic field generator 7 applies an artificial magnetic field in which a z-axis component, a y-axis component, and an x-axis component orthogonal to the z-axis direction and y-axis direction can be varied to the measurement region. An arithmetic control unit 5 has the magnetic field generator 7 generate an artificial magnetic field including a plurality of combinations obtained by changing the x-axis, y-axis and z-axis components, and the z-axis component being periodically changed. The arithmetic control unit calculates a magnetization value on the basis of a detection result by the polarimeter 4, and calculates an original magnetic existing field within the measurement region using the artificial magnetic field when the ratio between the time change of the magnetization value and the time change of the z-axis component meets a prescribed extreme value condition.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】計測領域に存在する原磁場を特定する新たな手法を提案すること。【解決手段】光源部2は、計測領域に配置されたガスセル3に、進行方向がz軸方向であり電場の振動方向がy軸方向である直線偏光を照射する。偏光計4は、ガスセル3を透過した光の光学特性を検出する。磁場発生器7は、z軸成分、y軸成分、z軸方向及びy軸方向に直交するx軸成分を可変とする人工磁場を計測領域に印加する。そして、演算制御部5は、x軸成分、y軸成分、及びz軸成分を変えた複数の組み合わせの人工磁場であってz軸成分を周期的に変化させた人工磁場を磁場発生器7に発生させ、偏光計4の検出結果に基づき磁化値を算出し、磁化値の時間変化とz軸成分の時間変化との比が所定の極値条件を満たしたときの人工磁場を用いて計測領域に存在する原磁場を算出する。【選択図】図1
