In conventional Kerr and Faraday microscopy, the sample is illuminated with plane-polarized light, and a magnetic domain contrast is generated by an analyzer making use of the Kerr or Faraday rotation. Here, we demonstrate possibilities of analyzer-free magneto-optical microscopy based on magnetization-dependent intensity modulations of the light. (i) The transverse Kerr effect can be applied for in-plane magnetized material, as demonstrated for an FeSi sheet. (ii) Illuminating that sample with circularly polarized light leads to a domain contrast with a different symmetry from the conventional Kerr contrast. (iii) Circular polarization can also be used for perpendicularly magnetized material, as demonstrated for garnet and ultrathin CoFeB films. (iv) Plane-polarized light at a specific angle can be employed for both in-plane and perpendicular media. (v) Perpendicular light incidence leads to a domain contrast on in-plane materials that is quadratic in the magnetization and to a domain boundary contrast. (vi) Domain contrast can even be obtained without a polarizer. In cases (ii) and (iii), the contrast is generated by magnetic circular dichroism (i.e., differential absorption of left- and right-circularly polarized light induced by magnetization components along the direction of light propagation), while magnetic linear dichroism (differential absorption of linearly polarized light induced by magnetization components transverse to propagation) is responsible for the contrast in case (v). The domain–boundary contrast is due to the magneto-optical gradient effect. A domain–boundary contrast can also arise by interference of phase-shifted magneto-optical amplitudes. An explanation of these contrast phenomena is provided in terms of Maxwell–Fresnel theory.

中文翻译：

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无需分析仪、基于强度的宽场磁光显微镜

在传统的克尔和法拉第显微镜中，样品用平面偏振光照射，磁畴对比由分析仪利用克尔或法拉第旋转产生。在这里，我们展示了无分析仪的可能性基于光的磁化依赖强度调制的磁光显微镜。(i) 横向克尔效应可应用于面内磁化材料，如 FeSi 片所示。(ii) 用圆偏振光照射样品会导致域对比度与传统的克尔对比度不同。(iii) 圆极化也可用于垂直磁化材料，如石榴石和超薄 CoFeB 薄膜所示。(iv) 特定角度的平面偏振光可用于平面内和垂直介质。(v) 垂直光入射导致平面内材料的磁畴对比度为二次方，并导致磁畴边界对比度。(vi) 甚至可以在没有偏振器的情况下获得域对比度。在情况 (ii) 和 (iii) 中，对比度是由磁性圆二色性（即磁化分量沿光传播方向引起的左右圆偏振光的差异吸收）产生的，而磁性线性二色性（磁化分量横向引起的线性偏振光的差异吸收传播）负责情况（v）中的对比度。域边界对比是由于磁光梯度效应。相移磁光振幅的干涉也会产生域边界对比。根据麦克斯韦-菲涅耳理论提供了对这些对比现象的解释。由沿光传播方向的磁化分量引起的左和右圆偏振光的差异吸收），而磁线性二色性（由横向于传播的磁化分量引起的线性偏振光的差异吸收）负责以下情况的对比度（ v)。域边界对比是由于磁光梯度效应。相移磁光振幅的干涉也会产生域边界对比。根据麦克斯韦-菲涅耳理论提供了对这些对比现象的解释。由沿光传播方向的磁化分量引起的左和右圆偏振光的差异吸收），而磁线性二色性（由横向于传播的磁化分量引起的线性偏振光的差异吸收）负责以下情况的对比度（ v)。域边界对比是由于磁光梯度效应。相移磁光振幅的干涉也会产生域边界对比。根据麦克斯韦-菲涅耳理论提供了对这些对比现象的解释。域边界对比是由于磁光梯度效应。相移磁光振幅的干涉也会产生域边界对比。根据麦克斯韦-菲涅耳理论提供了对这些对比现象的解释。域边界对比是由于磁光梯度效应。相移磁光振幅的干涉也会产生域边界对比。根据麦克斯韦-菲涅耳理论提供了对这些对比现象的解释。