Sub-diffraction limited magneto-optical microscopy, such as Kerr or Faraday effect microscopy, provide many advantages to fields of science and technology for measuring, or imaging, the magnetization structures and magnetization domains of materials. Disclosed is a method and system for performing sub-diffraction limited magneto-optic microscopy. The method includes positioning a microlens or microlens layer relative to a surface of a sample to image the surface of the sample, forming a photonic nanojet to probe the surface of the sample, and receiving light reflected by the surface of the sample or transmitted through the sample at an imaging sensor. The methods and associated systems and devices enable sub-diffraction limited imaging of magnetic domains at resolutions 2 to 8 times the classical diffraction limit.

The inventive concepts provide a magnetic property measurement apparatus capable of quickly measuring a magnetic property of a subject without a decrease in a measurement speed that might occur due to an electromagnet. In addition, the inventive concepts provide a magnetic property measurement apparatus capable of monitoring a magnetization distribution of a memory device as an image and integrating images by using a TDI camera, thereby being capable of performing highly sensitive measurement and not having to capture images for a long time. The magnetic property measurement apparatus includes: a magnetic field generation unit configured to generate a magnetic field which is constant with time and varies with relative position; a mobile unit configured to move a subject to be measured in the magnetic field; and a measurement unit configured to measure a magnetic property of the subject moving in the magnetic field.

In an image acquisition system, a distortion distribution is easily measured in a wide range. A standard image of magnetic domain of a sample serving as a standard is acquired by radiation of light using a standard external magnetic field which serves as a standard, a plurality of magnetic domain images are acquired in a state where an external magnetic field is applied while being changed, a plurality of subtraction images obtained by subtracting the standard image of magnetic domain from each of the plurality of magnetic domain images are acquired, a magnetization reversal area in which a magnetic domain is reversed is extracted from each of the plurality of subtraction images, and a composite image having a plurality of magnetization reversal areas is acquired by compositing the plurality of subtraction images each having the magnetization reversal area.

A magnetic property measuring system includes coil structures configured to apply a magnetic field to a sample, a light source configured to irradiate incident light to the sample, and a detector configured to detect polarization of light reflected from the sample. The magnetic field is perpendicular to a surface of the sample. Each coil structure includes a pole piece and a coil surrounding an outer circumferential surface of the pole piece. A wavelength of the incident light is equal to or less than about 580 nm.

The inventive concepts provide a magnetic property measurement apparatus capable of quickly measuring a magnetic property of a subject without a decrease in a measurement speed that might occur due to an electromagnet. In addition, the inventive concepts provide a magnetic property measurement apparatus capable of monitoring a magnetization distribution of a memory device as an image and integrating images by using a TDI camera, thereby being capable of performing highly sensitive measurement and not having to capture images for a long time. The magnetic property measurement apparatus includes: a magnetic field generation unit configured to generate a magnetic field which is constant with time and varies with relative position; a mobile unit configured to move a subject to be measured in the magnetic field; and a measurement unit configured to measure a magnetic property of the subject moving in the magnetic field.

A method for measuring magnetic characteristics is the method including applying a first magnetic field to a continuously moving magnetic recording medium to magnetically saturate the magnetic recording medium, applying a first polarized light to a surface of the magnetic recording medium to which the first magnetic field is being applied, and measuring a light polarization state of a first reflected light that is reflected, applying a second magnetic field having an opposite direction of the first magnetic field to the continuously moving magnetic recording medium to magnetically saturate the magnetic recording medium, applying a second polarized light to the surface of the magnetic recording medium to which the second magnetic field is being applied, and measuring a light polarization state of a second reflected light that is reflected, applying a third magnetic field having an opposite direction of the second magnetic field to the continuously moving magnetic recording medium, applying a third polarized light to the surface of the magnetic recording medium to which the third magnetic field is being applied, and measuring a light polarization state of a third reflected light that is reflected, and adjusting a strength of the third magnetic field so that a measurement value of the light polarization state of the third reflected light is a mean value of a measurement value of the light polarization state of the first reflected light and a measurement value of the light polarization state of the second reflected light, and obtaining the strength of the third magnetic field when the measurement value of the light polarization state of the third reflected light becomes equal to the mean value.

A magnetic property measuring system may include a stage configured to load a sample and to rotate the sample about a rotation axis such that the stage rotates the sample by a rotation angle, the rotation axis extending normal to a top surface of the sample. The magnetic property measuring system may further include a polarizer having a first polarization axis, and an analyzer having a second polarization axis. The polarizer and the analyzer may enable the first and second polarization axes to be independently rotated based on the rotation angle of the sample.

The processing of information is performed using a magneto-optic circuit that modifies the polarization of light using the Kerr effect. Magneto-optic circuits perform digital-to-analog conversion, comparison of values, and mathematical operations. Current carrying wires pass near a fiber-optic that carries polarized light. Each individual wire contributes a modification to the polarization of the light based on the current carried in each wire. The modified light is passed through a polarizer, and the intensity of the light may be measured with a photodiode to produce an electrical signal representing a result.

A magnetic property measuring system includes coil structures configured to apply a magnetic field to a sample, a light source configured to irradiate incident light to the sample, and a detector configured to detect polarization of light reflected from the sample. The magnetic field is perpendicular to a surface of the sample. Each coil structure includes a pole piece and a coil surrounding an outer circumferential surface of the pole piece. A wavelength of the incident light is equal to or less than about 580 nm.

A magnetic property measuring system includes coil structures configured to apply a magnetic field to a sample, a light source configured to irradiate incident light to the sample, and a detector configured to detect polarization of light reflected from the sample. The magnetic field is perpendicular to a surface of the sample. Each coil structure includes a pole piece and a coil surrounding an outer circumferential surface of the pole piece. A wavelength of the incident light is equal to or less than about 580 nm.