PROBLEM TO BE SOLVED: To propose a new technique identifying an original magnetic field existing in a measurement region.SOLUTION: A light source section 2 irradiates a gas cell 3 disposed in a measurement region with linear polarization where a traveling direction is a z-axis direction and a vibration direction of an electric field is a y-axis direction. A polarimeter 4 detects optical characteristics of light transmitted through the gas cell 3. A magnetic field generator 7 applies artificial magnetic fields rendering a z-axis component, a y-axis component and a component of an x-axis perpendicular to the z-axis direction and the y-axis direction variable to the measurement region. Further, an arithmetic control section 5 causes a plurality of artificial magnetic fields obtained by changing the z-axis component and the other one of the y-axis component and the x-axis component to be generated in the magnetic field generator 7 in a state of one of the y-axis component and the x-axis component being a fixed value, calculates a magnetization value on the basis of detection results of the polarimeter 4 and calculates an original magnetic field existing in the measurement region by using the artificial magnetic fields when the magnetization value satisfies predetermined extreme value conditions.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、y軸成分及びx軸成分のうちの一方を固定値とした状態で、z軸成分と、y軸成分及びx軸成分のうちの他方とを変化させた複数の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
