A method for measuring magneto-optical Kerr signal

Abstract

The invention relates to the field of magnetic measurement of material surfaces, in particular to a magneto-optical Kerr signal measuring method. The measuring device comprises a laser, a polarizationcontroller, an isolator, a polarization-maintaining circulator, a polarizer, a polarization-maintaining fiber I, an electro-optic modulator, a polarization-maintaining fiber II, an aspherical mirror,a quarter-wave plate, a lens stage, an atomic force microscope, a probe, a sample, a magnet, a sample stage, a power supply, a photodetector, a signal generator, a power distributor I, a computer, alow-pass filter, a lock-in amplifier I, a frequency multiplier, a power distributor II, a lock-in amplifier II, an incident optical path, and a reflective optical path; the probe has a through hole; and the interferential method of two orthogonal polarization components of the same beam are used to obtain the Kerr angle information of the sample, and the influence of certain non-magnetic effects such as linear birefringence and linear dichroism from the device itself, on the measurement accuracy is reduced; and a main optical path is in the fiber, optical components in the optical path are reduced, the influence of stray light is lowered, and the signal to noise ratio is improved.

Description

technical field [0001] The invention relates to the field of material surface magnetic measurement, in particular to a magneto-optical Kerr signal measurement method for studying the magneto-optical Kerr signal on the material surface by using a single-beam interference method. Background technique [0002] The magneto-optical Kerr effect measurement device is an important means in the study of material surface magnetism. Its working principle is based on the magneto-optic Kerr effect caused by the interaction between light and magnetized media. Magnetic detection, and non-contact measurement can be realized, and it has important applications in the research of magnetic order, magnetic anisotropy, interlayer coupling and phase transition behavior of magnetic ultrathin films. The magneto-optical Kerr effect measurement device is mainly used to observe the magnetization of the sample surface by detecting the change of the polarization state of a beam of linearly polarized ligh...

AI Technical Summary

Problems solved by technology

Defect 1 of the existing technology: In the Kerr angle measurement experiment, some non-magnetic effects such as linear birefringence and linear dichroism will affect the accuracy of the measurement, and will also affect the polarization state of light. These effects are not only caused by the sample , also comes from the device itself; defect 2 of the prior art: the Kerr angle measurement experiment in the prior art usually adopts the scheme that the light beam propagates between the optical elements in the atmosphere, which is easily affected by the positional deviation of the optical elements, Affect the accuracy of the signal; defect three of the prior art: the light intensity of the local region of the sample surface detected by the traditional near-field Kerr microscope is relatively weak, resulting in a low signal-to-noise ratio, and the magneto-optical Kerr signal measurement method can Solve the problem

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