A correction method and device for Faraday rotation effect in magneto-optical spectroscopy

Abstract

The present disclosure relates to a method and device for correcting the Faraday rotation effect in magneto-optical spectroscopy testing. The method comprises: determining the angle corresponding to a first linear polarizer disposed in an excitation optical path of a magneto-optical spectroscopy testing system according to a target polarization state; determining the reference angle corresponding to a second linear polarizer disposed in a collection optical path of the magneto-optical spectroscopy testing system according to a preset polarization configuration; when the magneto-optical spectroscopy testing system is in different magnetic field intensities, determining a first mapping relationship between the angle of a first half-wave plate disposed in the excitation optical path and different magnetic field intensities, and a second mapping relationship between the angle of a second half-wave plate disposed in the collection optical path and different magnetic field intensities, respectively, based on the reference angle, thereby determining a calibration scheme for the magneto-optical spectroscopy testing system under the target magnetic field intensity. The disclosed embodiment can utilize the angle adjustment of the linear polarizer and the half-wave plate to correct the polarization error caused by the Faraday effect, and has high applicability.

Description

Technical Field

[0001] The present disclosure relates to the technical field of magneto-optical spectroscopy measurement, and in particular to a correction method and device for Faraday rotation effect in magneto-optical spectroscopy testing. Background Art

[0002] In magneto-optical spectroscopy, precise control of the polarization state of light allows for the analysis of the underlying mechanisms of light-matter interactions, the differentiation of different types of optical and magnetic signals, and the investigation of the internal symmetries and coupling effects of low-dimensional and low-dimensional magnetic materials. However, optical components in magneto-optical spectroscopy systems (such as lenses, objectives, and optical windows) can affect the polarization state of linearly polarized light due to the Faraday effect, leading to systematic errors and compromising the accuracy and reliability of magneto-optical spectroscopy. Summary of the Invention

[0003] In view of this, the present disclosure proposes a technical solution of a method and device for correcting the Faraday rotation effect in magneto-optical spectroscopy.

[0004] In one aspect of the present disclosure, a method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing is provided, comprising: determining an angle corresponding to a first linear polarizer disposed in an excitation light path of a magneto-optical spectroscopy testing system according to a target polarization state, wherein the target polarization state includes the polarization angle of the target excitation light corresponding to the excitation light path; determining a reference angle corresponding to a second linear polarizer disposed in a collection light path of the magneto-optical spectroscopy testing system according to a preset polarization configuration, wherein the preset polarization configuration is used to indicate a relationship between the polarization direction of the target excitation light and the polarization direction of the collection light corresponding to the collection light path; and determining a reference angle corresponding to a second linear polarizer disposed in a collection light path of the magneto-optical spectroscopy testing system according to a preset polarization configuration when the magneto-optical spectroscopy testing system is in different magnetic field intensities according to the reference angle. degrees, calibrating the first half-wave plate provided in the excitation optical path, and determining a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities; when the magneto-optical spectroscopy test system is in different magnetic field intensities, calibrating the second half-wave plate provided in the collection optical path according to the reference angle, and determining a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities; determining a calibration scheme of the magneto-optical spectroscopy test system under the target magnetic field intensity according to the first mapping relationship and the second mapping relationship, wherein the calibration scheme is used to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is in the target magnetic field intensity.

[0005] In one possible implementation, determining the reference angle corresponding to the second linear polarizer set in the collection light path of the magneto-optical spectroscopy testing system according to a preset polarization configuration includes: when only the first linear polarizer is set in the excitation light path and only the second linear polarizer is set in the collection light path, determining a third mapping relationship, wherein the third mapping relationship is used to indicate the intensity of the collected light when the second linear polarizer is at different angles; and determining the reference angle according to the reference intensity of the collected light under the preset polarization configuration and the third mapping relationship.

[0006] In a possible implementation, when the magneto-optical spectroscopy testing system is in different magnetic field intensities, the first half-wave plate provided in the excitation light path is calibrated according to the reference angle to determine a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities, including: when the magneto-optical spectroscopy testing system is in zero magnetic field intensity, and the first linear polarizer and the first half-wave plate are provided in the excitation light path, and only the second linear polarizer is provided in the collection light path, the second linear polarizer is set at the reference angle, the angle of the first half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and a first initial angle corresponding to the first half-wave plate is determined; when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the first linear polarizer and the first half-wave plate are provided in the excitation light path, and only the second linear polarizer is provided in the collection light path, the second linear polarizer is set at the reference angle, the angle corresponding to the first half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and a first initial adjustment angle corresponding to the first half-wave plate under the magnetic field intensity is determined; and the first mapping relationship is determined according to the first initial angle and the first initial adjustment angles corresponding to the first half-wave plate under different magnetic field intensities.

[0007] In a possible implementation, the first mapping relationship is determined based on the first initial angle and the first initial adjustment angle corresponding to the first half-wave plate under different magnetic field intensities, including: when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is set with the first linear polarizer and the first half-wave plate, and the collection light path is set with the second linear polarizer and the second half-wave plate, 1 / 2 of the first initial adjustment angle corresponding to the first half-wave plate under the magnetic field intensity is determined as the first target adjustment angle corresponding to the first half-wave plate under the magnetic field intensity; the first mapping relationship is determined based on the first initial angle and the first target adjustment angle corresponding to the first half-wave plate under different magnetic field intensities.

[0008] In a possible implementation, when the magneto-optical spectroscopy test system is in different magnetic field intensities, the second half-wave plate provided in the collection light path is calibrated according to the reference angle to determine a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities, including: when the magneto-optical spectroscopy test system is in zero magnetic field intensity, and the excitation light path is only provided with the first linear polarizer, and the collection light path is provided with the second linear polarizer and the second half-wave plate, the second linear polarizer is set at the reference angle, the angle of the second half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and the second initial angle corresponding to the second half-wave plate is determined; when the magneto-optical spectroscopy test system is in any non-zero magnetic field intensity, and the excitation light path is only provided with the first linear polarizer, and the collection light path is provided with the second linear polarizer and the second half-wave plate, the second linear polarizer is set at the reference angle, the angle corresponding to the second half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity is determined; and the second mapping relationship is determined according to the second initial angle and the second initial adjustment angle corresponding to the second half-wave plate under different magnetic field intensities.

[0009] In one possible implementation, the second mapping relationship is determined based on the second initial angle and the second initial adjustment angle corresponding to the second half-wave plate under different magnetic field intensities, including: when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is set with the first linear polarizer and the first half-wave plate, and the collection light path is set with the second linear polarizer and the second half-wave plate, 1 / 2 of the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity is determined as the second target adjustment angle corresponding to the second half-wave plate under the magnetic field intensity; the second mapping relationship is determined based on the second initial angle and the second target adjustment angle corresponding to the second half-wave plate under different magnetic field intensities.

[0010] In a possible implementation, the intensity of the collected light is determined by a power meter disposed behind the second linear polarizer.

[0011] In a possible implementation, the preset polarization configuration includes: the polarization direction corresponding to the target excitation light is parallel to the polarization direction corresponding to the collected light, or the polarization direction corresponding to the target excitation light is perpendicular to the polarization direction corresponding to the collected light.

[0012] In a possible implementation, during the calibration process of the second linear polarizer, the first half-wave plate, and the second half-wave plate, the collected light is reflected signal light from a substrate on which a test object is placed in the magneto-optical spectroscopy testing system.

[0013] According to another aspect of the present disclosure, a correction device for the Faraday rotation effect in magneto-optical spectroscopy testing is provided, comprising: a first angle determination module for determining an angle corresponding to a first linear polarizer disposed in an excitation light path of a magneto-optical spectroscopy testing system according to a target polarization state, wherein the target polarization state includes the polarization angle of the target excitation light corresponding to the excitation light path; a second angle determination module for determining a reference angle corresponding to a second linear polarizer disposed in a collection light path of the magneto-optical spectroscopy testing system according to a preset polarization configuration, wherein the preset polarization configuration is used to indicate a relationship between the polarization direction of the target excitation light and the polarization direction of the collection light corresponding to the collection light path; a first mapping determination module for determining, when the magneto-optical spectroscopy testing system is in different magnetic field intensities, According to the reference angle, the first half-wave plate arranged in the excitation light path is calibrated to determine the first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities; the second mapping determination module is used to calibrate the second half-wave plate arranged in the collection light path according to the reference angle when the magneto-optical spectroscopy test system is in different magnetic field intensities, to determine the second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities; the calibration scheme determination module is used to determine the calibration scheme of the magneto-optical spectroscopy test system under the target magnetic field intensity according to the first mapping relationship and the second mapping relationship, wherein the calibration scheme is used to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is in the target magnetic field intensity.

[0014] In the disclosed embodiment, the target excitation light can be initialized by determining the angle corresponding to a first linear polarizer disposed in the excitation light path of the magneto-optical spectroscopy testing system so that the polarization angle of the target excitation light corresponding to the excitation light path is in a target polarization state. The reference angle corresponding to a second linear polarizer disposed in the collection light path of the magneto-optical spectroscopy testing system is determined to set the relationship between the polarization direction of the target excitation light and the polarization direction of the collection light corresponding to the collection light path to meet a preset polarization configuration, providing a reliable basis for the subsequent calibration process. When the magneto-optical spectroscopy test system is in different magnetic field intensities, the first half-wave plate arranged in the excitation light path is calibrated according to the reference angle, and a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities can be determined, which serves as a basis for correcting the polarization error of the target excitation light caused by the Faraday rotation effect; when the magneto-optical spectroscopy test system is in different magnetic field intensities, the second half-wave plate arranged in the collection light path is calibrated according to the reference angle, and a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities can be determined, which serves as a basis for correcting the polarization error of the collected light caused by the Faraday rotation effect; based on the first mapping relationship and the second mapping relationship, a calibration scheme for the magneto-optical spectroscopy test system under the target magnetic field intensity can be determined to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is in the target magnetic field intensity. Through the correction method of the embodiment of the present invention, the angle adjustment of the first linear polarizer, the second linear polarizer, the first half-wave plate and the second half-wave plate can be used to compensate for the polarization deviation of the target excitation light and the collected light caused by the Faraday effect, thereby avoiding the error accumulation caused by the change of polarization state during the magneto-optical spectrum test. It has high correction accuracy and stability, and does not require the customization of special optical elements. It is low-cost and easy to implement, has high applicability, can be applied to a variety of different magneto-optical spectrum test systems, and is suitable for different spectrum test needs.

[0015] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0017] Figure 1 A flow chart showing a method for correcting the Faraday rotation effect in magneto-optical spectroscopy according to an embodiment of the present disclosure is provided;

[0018] Figure 2 A schematic diagram showing a method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing according to an embodiment of the present disclosure is shown;

[0019] Figure 3 A schematic structural diagram of a magneto-optical spectroscopy testing system according to an embodiment of the present disclosure is shown;

[0020] Figure 4 A schematic structural diagram of a magneto-optical spectroscopy testing system according to an embodiment of the present disclosure is shown;

[0021] Figure 5 A schematic structural diagram of a magneto-optical spectroscopy testing system according to an embodiment of the present disclosure is shown;

[0022] Figure 6 A block diagram of a device for correcting the Faraday rotation effect in magneto-optical spectroscopy testing according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0023] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0024] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0025] The term "and / or" herein simply describes an association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent the existence of three situations: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

[0026] In addition, numerous specific details are provided in the following detailed description to better illustrate the present disclosure. Those skilled in the art will appreciate that the present disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art are not described in detail in order to highlight the main points of the present disclosure.

[0027] Magneto-optical spectroscopy, as an important research tool, is widely used in the exploration of novel magnetic materials, spintronics devices, and quantum functional materials. Through the magneto-optical effect, key physical parameters of materials, such as spin alignment, spin-phonon coupling, exciton energy, and exciton dynamics, can be non-destructively determined under varying temperatures, magnetic fields, and optical polarization conditions. Magneto-optical Raman spectroscopy, fluorescence spectroscopy, and magneto-optical Kerr spectroscopy are key tools in magneto-optical spectroscopy.

[0028] The polarization state of light is crucial in magneto-optical spectroscopy. It directly determines how light interacts with electrons, phonons, and spins within a material, providing insights into material symmetries and magnetic interactions. Precisely controlling the polarization state of light allows for the analysis of the underlying mechanisms of light-matter interactions, distinguishing between different types of optical and magnetic signals, and investigating the internal symmetries and coupling effects of low-dimensional and low-dimensional magnetic materials. This is crucial for advancing the development of spin-based quantum devices and the exploration of novel functional materials.

[0029] However, in polarized magneto-optical spectroscopy testing, the optical components in the system (such as lenses, objectives, and optical windows) may cause the polarization state of linearly polarized light to change due to the Faraday effect under the action of an external magnetic field, thereby introducing systematic errors. The Faraday effect is a polarization rotation phenomenon of linearly polarized light induced by an external magnetic field. When linearly polarized light passes through a medium where a magnetic field is applied along the direction of light propagation, its polarization plane rotates. The rotation angle is proportional to the Verdet constant, optical path length, and magnetic field strength of the medium, and is also affected by parameters such as the wavelength and temperature of the light. In magneto-optical spectroscopy testing, the optical components close to the sample (especially the objective lens) may cause significant polarization rotation of the linearly polarized light due to the presence of a residual magnetic field, causing the polarization state of the actual incident light on the sample to deviate from the original setting, thereby affecting the interaction between light and the sample, causing the test signal (such as Raman scattering or fluorescence) to deviate from the true value.

[0030] In the prior art, high-performance optical components or polarization correction and compensation methods are usually used to correct the systematic errors introduced by the Faraday effect, thereby improving the accuracy of magneto-optical spectroscopy testing. For example, the use of objective lenses and optical windows with low Verdet constants and strong resistance to magnetic field interference can reduce the influence of the Faraday effect. However, the cost of such high-performance optical components is high, and their compatibility with existing test systems is poor, making it difficult to simultaneously meet complex test conditions such as low temperature, strong magnetic field, and high resolution. In addition, the Faraday effect is a ubiquitous optical phenomenon. The use of low Verdet constant components can only reduce the polarization rotation angle, but cannot fundamentally eliminate the interference of the effect. Under strong magnetic field conditions, since the rotation angle of the Faraday effect is linearly related to the magnetic field strength, its influence is still significant.

[0031] Prior art also proposes using circularly polarized light as excitation light to circumvent the Faraday effect. While this approach can reduce the impact of the Faraday effect, circularly polarized excitation light is not suitable for all test scenarios. In some test scenarios, linearly polarized light excitation is required to detect the properties of the test sample, making this approach less applicable.

[0032] The prior art also proposes a method of compensating for the Faraday effect by utilizing the symmetry characteristics of the sample to be tested. Although this method can achieve correction under certain conditions, it relies on the symmetry characteristics of the sample to be tested and is also not universally applicable.

[0033] In light of this, the present disclosure provides a method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing. By introducing two linear polarizers and two half-wave plates into the external, non-magnetic optical path of the magneto-optical spectroscopy testing system, the method utilizes flexible and precise adjustment of the linear polarizer and half-wave plate angles to accurately compensate for polarization errors in the excitation and collection light caused by the Faraday effect, ensuring polarization consistency during magneto-optical spectroscopy testing. This method is highly applicable and can be applied to a variety of different magneto-optical spectroscopy testing systems. Furthermore, the method does not require the customization of special optical components, making it low-cost and easy to implement. The following details the method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing provided by the present disclosure.

[0034] Figure 1 A flow chart of a method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing according to an embodiment of the present disclosure is shown. The method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing can be executed by an electronic device such as a terminal device or a server. The terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. The method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing can be implemented by a processor calling computer-readable instructions stored in a memory. Alternatively, the method for correcting the Faraday rotation effect in magneto-optical spectroscopy testing can be executed by a server. As Figure 1 As shown, the correction method for the Faraday rotation effect in magneto-optical spectroscopy testing includes:

[0035] In step S11, the angle corresponding to the first linear polarizer provided in the excitation light path of the magneto-optical spectroscopy testing system is determined according to the target polarization state, wherein the target polarization state includes the polarization angle of the target excitation light corresponding to the excitation light path.

[0036] The magneto-optical spectroscopy testing system herein can refer to any testing system for implementing magneto-optical spectroscopy testing. Its specific form can be flexibly configured according to actual usage requirements. For example, it can be a magneto-optical Raman spectroscopy testing system, a magneto-optical fluorescence spectroscopy testing system, etc., and this disclosure does not specifically limit this. It should be noted that the excitation optical path of the magneto-optical spectroscopy testing system is a non-magnetic optical path that is not covered by the magnetic field.

[0037] The target polarization state can represent the polarization state of the target excitation light used for magneto-optical spectroscopy testing and is used to indicate the polarization angle of the target excitation light. The specific content of the target polarization state, i.e., the specific polarization angle, can be flexibly set according to actual usage requirements and is not specifically limited in this disclosure.

[0038] Based on the target polarization state, the angle corresponding to the first linear polarizer disposed in the excitation light path of the magneto-optical spectroscopy testing system can be determined. This first linear polarizer can then be used to initialize the target excitation light for subsequent magneto-optical spectroscopy testing. The specific form of the first linear polarizer can be referenced to embodiments in related art and is not specifically limited in this disclosure.

[0039] Figure 2 FIG. 1 is a schematic diagram showing a method for correcting the Faraday rotation effect in magneto-optical spectroscopy according to an embodiment of the present disclosure. Figure 2 As shown, a first linear polarizer 201 is provided in the excitation light path corresponding to the magneto-optical spectroscopy testing system 200. Upon entering the first linear polarizer 201, initial excitation light, either with or without an initial polarization state, is adjusted to target excitation light with a target polarization state. The specific form and source of the initial excitation light can be found in related art implementations and are not specifically limited in this disclosure.

[0040] The equipment environment of the magneto-optical spectroscopy testing system (including the ambient temperature corresponding to each optical element, etc.) and the specific method of applying the magnetic field of the magneto-optical spectroscopy testing system can be flexibly set according to actual usage requirements, and this disclosure does not make specific limitations on this.

[0041] Figure 3 FIG. 1 shows a schematic structural diagram of a magneto-optical spectrum testing system according to an embodiment of the present disclosure. Figure 3 As shown, the external magnetic field of the magneto-optical spectroscopy testing system 300 is generated by a permanent magnet 301 in a room temperature environment, and the objective lens 302 and the sample to be tested 303 corresponding to the magneto-optical spectroscopy testing system 300 are both set in a room temperature environment.

[0042] Figure 4 FIG. 1 shows a schematic structural diagram of a magneto-optical spectrum testing system according to an embodiment of the present disclosure. Figure 4As shown, the external magnetic field of the magneto-optical spectroscopy testing system 400 is generated by a superconducting coil 402 disposed in a cryostat 401. The objective lens 403 corresponding to the magneto-optical spectroscopy testing system 400 is placed in a room temperature environment, and the sample to be tested 404 is placed in a low temperature constant temperature environment within the cryostat 401. Target excitation light enters the cryostat 401 through an optical window 405 on the cryostat 401.

[0043] Figure 5 FIG. 1 shows a schematic structural diagram of a magneto-optical spectrum testing system according to an embodiment of the present disclosure. Figure 5 As shown, the external magnetic field of the magneto-optical spectroscopy testing system 500 is generated by a superconducting coil 502 disposed in a cryostat 501. The objective lens 503 and the sample to be tested 504 corresponding to the magneto-optical spectroscopy testing system 500 are disposed in a low-temperature constant temperature environment within the cryostat 501. The target excitation light first passes through a reflector 505 disposed in a room temperature environment before entering the cryostat 501 through an optical window 506 on the cryostat 501.

[0044] In step S12, according to a preset polarization configuration, a reference angle corresponding to a second linear polarizer arranged in the collection light path of the magneto-optical spectroscopy testing system is determined, wherein the preset polarization configuration is used to indicate the relationship between the polarization direction of the target excitation light and the polarization direction of the collection light corresponding to the collection light path.

[0045] With the above Figure 2 For example, Figure 2 As shown, the collection light path of the magneto-optical spectroscopy testing system 200 is equipped with a second linear polarizer 202, which can be used to adjust the polarization state of the corresponding collected light in the collection light path. The specific form of the second linear polarizer can be referenced in related art implementations and is not specifically limited in this disclosure. It should be noted that the collection light path of the magneto-optical spectroscopy testing system is also a non-magnetic light path that is not covered by the magnetic field.

[0046] The preset polarization configuration is used to indicate the relationship between the polarization direction of the excitation light and the polarization direction of the collected light. Its specific form can be flexibly set according to actual usage requirements, and this disclosure does not make specific limitations on this.

[0047] In a possible implementation, the preset polarization configuration includes: the polarization direction corresponding to the target excitation light is parallel to the polarization direction corresponding to the collected light, or the polarization direction corresponding to the target excitation light is perpendicular to the polarization direction corresponding to the collected light.

[0048] The polarization configuration in which the polarization direction of the target excitation light is parallel to the polarization direction of the collected light can be denoted as the XX configuration or the Z(XX)Z configuration. The polarization configuration in which the polarization direction of the target excitation light is perpendicular to the polarization direction of the collected light can be denoted as the XY configuration or the Z(XX)Z configuration. Here, the first X represents the polarization direction of the target excitation light, and the second X, or Y, represents the polarization direction of the collected light.

[0049] According to the preset polarization configuration, the reference angle corresponding to the second linear polarizer can be determined so that the polarization direction corresponding to the collected light conforms to the preset polarization configuration to meet the requirements of magneto-optical spectrum testing.

[0050] The specific process of determining the reference angle corresponding to the second linear polarizer according to the preset polarization configuration will be described in detail later and will not be elaborated here.

[0051] In step S13, when the magneto-optical spectroscopy test system is in different magnetic field strengths, the first half-wave plate arranged in the excitation light path is calibrated according to the reference angle to determine the first mapping relationship between the angle of the first half-wave plate and different magnetic field strengths.

[0052] With the above Figure 2 For example, Figure 2 As shown, the excitation optical path of magneto-optical spectroscopy testing system 200 is provided with a first half-wave plate 203. In the presence of zero magnetic field strength, the fast axis of first half-wave plate 203 is parallel to first linear polarizer 201, thereby correcting the polarization error of the target excitation light caused by the Faraday rotation effect. The specific form of the first half-wave plate can be referenced to embodiments in the related art and is not specifically limited in this disclosure.

[0053] When the magneto-optical spectrum test system is in any magnetic field strength, the first half-wave plate can be calibrated according to the reference angle corresponding to the second linear polarizer to determine the angle corresponding to the first half-wave plate when the magneto-optical spectrum test system is in the magnetic field strength.

[0054] According to the angle corresponding to the first half-wave plate when the magneto-optical spectroscopy test system is in different magnetic field intensities, a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities can be constructed, thereby providing a basis for correcting the polarization error of the target excitation light caused by the Faraday rotation effect.

[0055] The process of calibrating the first half-wave plate and determining the first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities will be described in detail later and will not be elaborated here.

[0056] In step S14, when the magneto-optical spectroscopy test system is in different magnetic field strengths, the second half-wave plate arranged in the collection light path is calibrated according to the reference angle to determine the second mapping relationship between the angle of the second half-wave plate and different magnetic field strengths.

[0057] With the above Figure 2 For example, Figure 2 As shown, the collection optical path of magneto-optical spectroscopy testing system 200 is provided with a second half-wave plate 204. In the presence of zero magnetic field strength, the fast axis of second half-wave plate 204 is parallel to first linear polarizer 201, thereby correcting the polarization error of the collected light caused by the Faraday rotation effect. The specific form of the second half-wave plate can be referenced to embodiments in the related art and is not specifically limited in this disclosure.

[0058] When the magneto-optical spectrum test system is in any magnetic field strength, the second half-wave plate can be calibrated according to the reference angle corresponding to the second linear polarizer to determine the angle corresponding to the second half-wave plate when the magneto-optical spectrum test system is in the magnetic field strength.

[0059] According to the angle corresponding to the second half-wave plate when the magneto-optical spectroscopy test system is in different magnetic field intensities, a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities can be constructed, thereby providing a basis for correcting the polarization error of the collected light caused by the Faraday rotation effect.

[0060] The process of calibrating the second half-wave plate and determining the second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities will be described in detail later and will not be elaborated here.

[0061] In step S15, a calibration scheme of the magneto-optical spectroscopy test system under the target magnetic field strength is determined based on the first mapping relationship and the second mapping relationship, wherein the calibration scheme is used to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is under the target magnetic field strength.

[0062] When the magneto-optical spectroscopy test system is in a target magnetic field strength, the angle of the first half-wave plate and the angle of the second half-wave plate can be determined respectively according to the first mapping relationship and the second mapping relationship, and then the calibration scheme of the magneto-optical spectroscopy test system under the target magnetic field strength is determined, so as to correct the polarization error of the target excitation light and the polarization error of the collected light respectively, eliminate the influence of the Faraday rotation effect, and thus improve the accuracy and reliability of the magneto-optical spectroscopy test.

[0063] The specific method for determining the calibration scheme here can be flexibly set according to actual usage requirements and depends on the specific form of the magneto-optical spectroscopy testing system. This disclosure does not make specific limitations on this.

[0064] In one example, when the magneto-optical spectroscopy test system is a magneto-optical Raman spectroscopy test system, the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is under the target magnetic field intensity can be directly determined based on the first mapping relationship and the second mapping relationship, and used as a calibration scheme.

[0065] In one possible implementation, when the magneto-optical spectroscopy test system is a magneto-optical fluorescence spectroscopy test system, a calibration scheme for the magneto-optical spectroscopy test system under a target magnetic field strength is determined according to a first mapping relationship and a second mapping relationship, including: determining, according to the first mapping relationship and the second mapping relationship, a first target angle corresponding to the first half-wave plate and a second target angle corresponding to the second half-wave plate when the magneto-optical spectroscopy test system is in the target magnetic field strength; determining a wavelength correction coefficient between the target excitation light and the collected light according to the characteristic that the Faraday effect is approximately proportional to the square of the wavelength energy, wherein the wavelength correction coefficient is used to correct the second target angle; determining a calibration scheme according to the wavelength correction coefficient, the first target angle corresponding to the first half-wave plate, and the second target angle corresponding to the second half-wave plate.

[0066] Among them, the specific method of determining the wavelength correction coefficient between the target excitation light and the collected light can refer to the implementation methods in the relevant technology, and this disclosure does not make specific limitations on this.

[0067] In one example, the wavelength correction coefficient may be determined based on an empirical formula that the Faraday effect is inversely proportional to the square of the wavelength.

[0068] Specifically, the Faraday rotation angle θ caused by the Faraday effect is proportional to the product of the magnetic field intensity B corresponding to the magneto-optical fluorescence spectroscopy test system and the optical path length L corresponding to the target excitation light. This relationship can be expressed as formula (1):

[0069] θ=VBL (1)

[0070] Where V is the Verdet constant, which is used to quantify the response of any material to a magnetic field and can be determined by the Becquerel formula. The Becquerel formula can be expressed as formula (2):

[0071]

[0072] Where, e represents the charge of the electron; m e represents the mass of the electron; λ represents the wavelength of the target excitation light; represents the speed of light; dn / dλ is used to express the dispersion relation corresponding to any material.

[0073] According to formula (2), the specific value of the Verdet constant V is affected by the material properties and temperature, as well as the wavelength of the target excitation light. In practical applications, it is usually impossible to accurately measure the Verdet constant V at each different wavelength. Therefore, the approximate relationship between the Verdet constant V and wavelength λ can be analyzed through the Cauchy dispersion relation to calculate the Verdet constant V relatively accurately.

[0074] The Cauchy dispersion relation can be expressed as formula (3):

[0075]

[0076] By taking the derivative of formula (3), we can get formula (4):

[0077]

[0078] According to formula (2) and formula (4), the relationship between the Verdet constant V and the wavelength λ satisfies formula (5):

[0079]

[0080] According to formula (5), the Verdet constant V is approximately inversely proportional to the square of the wavelength λ, that is, it is proportional to the square of the photon energy of the target excitation light. Then, the wavelength correction coefficient can be determined through the above analysis process.

[0081] In one example, the energy of the excitation light is 2.33 eV (wavelength is 532 nm), the energy of the collected light is 1.38 eV (wavelength is 900 nm), and when the magneto-optical spectroscopy test system is in the target magnetic field intensity, the first target angle corresponding to the first half-wave plate is θ / 2, and the second target angle corresponding to the second half-wave plate is The wavelength correction factor can be determined as (1.38 / 2.33) based on the empirical formula of the Faraday effect and the inverse square of the wavelength. 2 , it can be determined that when the magneto-optical spectrum test system is in the target magnetic field strength, the calibration scheme is to set the angle of the first half-wave plate to θ / 2 and the angle of the second half-wave plate to

[0082] In the disclosed embodiment, the target excitation light can be initialized by determining the angle corresponding to a first linear polarizer disposed in the excitation light path of the magneto-optical spectroscopy testing system so that the polarization angle of the target excitation light corresponding to the excitation light path is in a target polarization state. The reference angle corresponding to a second linear polarizer disposed in the collection light path of the magneto-optical spectroscopy testing system is determined to set the relationship between the polarization direction of the target excitation light and the polarization direction of the collection light corresponding to the collection light path to meet a preset polarization configuration, providing a reliable basis for the subsequent calibration process. When the magneto-optical spectroscopy test system is in different magnetic field intensities, the first half-wave plate arranged in the excitation light path is calibrated according to the reference angle, and a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities can be determined, which serves as a basis for correcting the polarization error of the target excitation light caused by the Faraday rotation effect; when the magneto-optical spectroscopy test system is in different magnetic field intensities, the second half-wave plate arranged in the collection light path is calibrated according to the reference angle, and a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities can be determined, which serves as a basis for correcting the polarization error of the collected light caused by the Faraday rotation effect; based on the first mapping relationship and the second mapping relationship, a calibration scheme for the magneto-optical spectroscopy test system under the target magnetic field intensity can be determined to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is in the target magnetic field intensity. Through the correction method of the embodiment of the present invention, the angle adjustment of the first linear polarizer, the second linear polarizer, the first half-wave plate and the second half-wave plate can be used to compensate for the polarization deviation of the target excitation light and the collected light caused by the Faraday effect, thereby avoiding the error accumulation caused by the change of polarization state during the magneto-optical spectrum test. It has high correction accuracy and stability, and does not require the customization of special optical elements. It is low-cost and easy to implement, has high applicability, can be applied to a variety of different magneto-optical spectrum test systems, and is suitable for different spectrum test needs.

[0083] In one possible implementation, according to a preset polarization configuration, a reference angle corresponding to a second linear polarizer arranged in a collection light path of a magneto-optical spectroscopy testing system is determined, including: when only a first linear polarizer is set in an excitation light path and only a second linear polarizer is set in a collection light path, a third mapping relationship is determined, wherein the third mapping relationship is used to indicate the intensity of the collected light when the second linear polarizer is at different angles; and a reference angle is determined based on the reference intensity of the collected light under the preset polarization configuration and the third mapping relationship.

[0084] When only the first linear polarizer is provided in the excitation light path, and only the second linear polarizer is provided in the collection light path, the corresponding variation range of the collected light intensity can be determined by periodically adjusting the second linear polarizer. Typically, when the polarization direction of the collected light and the target excitation light form an XX configuration, the collected light intensity is at its maximum within this variation range; when the polarization direction of the collected light and the target excitation light form an XY configuration, the collected light intensity is at its minimum within this variation range.

[0085] Based on this, by determining the intensity of the collected light when the second linear polarizer is at different angles, a third mapping relationship between the angle of the second linear polarizer and the intensity of the collected light can be analyzed. This allows for rapid determination of the reference angle corresponding to the second linear polarizer based on the third mapping relationship and the reference intensity of the collected light under a preset polarization configuration, depending on different usage requirements. The specific method for determining the intensity of the collected light can be flexibly configured based on actual usage requirements and is not specifically limited in this disclosure.

[0086] In a possible implementation, the intensity of the collected light is determined by a power meter disposed behind the second linear polarizer.

[0087] Along the propagation direction of the collected light, a power meter positioned behind the second linear polarizer can be used to measure the intensity of the collected light in real time. It is important to note that there should be no other components between the second linear polarizer and the power meter, and the distance between the power meter and the second linear polarizer should meet a preset threshold. The specific value of the preset threshold can be flexibly set based on actual usage requirements and is not specifically limited in this disclosure.

[0088] In one possible implementation, when the magneto-optical spectroscopy test system is in different magnetic field strengths, the first half-wave plate arranged in the excitation light path is calibrated according to the reference angle, and the first mapping relationship between the angle of the first half-wave plate and the different magnetic field strengths is determined, including: when the magneto-optical spectroscopy test system is in zero magnetic field strength, and the first linear polarizer and the first half-wave plate are set in the excitation light path, and only the second linear polarizer is set in the collection light path, the second linear polarizer is set at the reference angle, the angle of the first half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and the first initial angle corresponding to the first half-wave plate is determined; when the magneto-optical spectroscopy test system is in any non-zero magnetic field strength, and the first linear polarizer and the first half-wave plate are set in the excitation light path, and only the second linear polarizer is set in the collection light path, the second linear polarizer is set at the reference angle, the angle corresponding to the first half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and the first initial adjustment angle corresponding to the first half-wave plate under the magnetic field strength is determined; the first mapping relationship is determined according to the first initial angle and the first initial adjustment angle corresponding to the first half-wave plate under different magnetic field strengths.

[0089] When the magneto-optical spectroscopy test system is in a zero magnetic field intensity, and the first linear polarizer and the first half-wave plate are set in the excitation light path, and only the second linear polarizer is set in the collection light path, the second linear polarizer is set at a reference angle, and the angle of the first half-wave plate can be adjusted until the intensity of the collected light meets the reference light intensity, and the first initial angle corresponding to the first half-wave plate is determined, which will serve as a benchmark for subsequent calibration of the first half-wave plate when the magneto-optical spectroscopy test system is in a non-zero magnetic field intensity.

[0090] In one example, the preset polarization configuration is an XY configuration, the reference angle corresponding to the second linear polarizer is β, and the intensity of the collected light is detected by a power meter disposed behind the second linear polarizer.

[0091] Set the angle of the second linear polarizer to β and adjust the angle of the first half-wave plate until the light intensity reading corresponding to the power meter is minimum, indicating that the light intensity of the collected light meets the reference light intensity corresponding to the XY configuration. The angle corresponding to the first half-wave plate at this time is determined as the first initial angle corresponding to the first half-wave plate.

[0092] Furthermore, for any preset polarization configuration, in order to improve the operability of the calibration process, reduce the difficulty of calibration, and improve the calibration accuracy, the angle of the second linear polarizer can be first set to β, and after determining the angle corresponding to the first half-wave plate when the light intensity reading corresponding to the power meter is minimum based on the aforementioned process, the difference between the reference angle corresponding to the second linear polarizer in the preset polarization configuration and the angle β is added to this angle to determine the first initial angle corresponding to the first half-wave plate.

[0093] When the magneto-optical spectroscopy test system is subjected to any non-zero magnetic field intensity, and the excitation light path is provided with a first linear polarizer and a first half-wave plate, and the collection light path is provided with only a second linear polarizer, the second linear polarizer is set at a reference angle. Referring to the aforementioned description, the angle corresponding to the first half-wave plate can be adjusted until the intensity of the collected light meets the reference intensity, thereby determining a first initial adjustment angle corresponding to the first half-wave plate at that magnetic field intensity. The first initial adjustment angle corresponding to the first half-wave plate at any magnetic field intensity can represent an adjustment angle relative to the first initial angle.

[0094] Taking the above-mentioned preset polarization configuration as an XY configuration, the reference angle corresponding to the second linear polarizer is β, and detecting the intensity of the collected light by a power meter arranged behind the second linear polarizer as an example, the angle of the second linear polarizer is set to β, and the first half-wave plate is set to a first initial angle. On this basis, the angle of the first half-wave plate is adjusted until the light intensity reading corresponding to the power meter is minimum, indicating that the intensity of the collected light meets the reference light intensity corresponding to the XY configuration, and the first initial adjustment angle θ corresponding to the first half-wave plate is determined.

[0095] Similarly, for any preset polarization configuration, the angle of the second linear polarizer can be first set to β. After determining the angle of the first half-wave plate when the light intensity reading corresponding to the power meter is minimum based on the aforementioned process, the difference between the reference angle corresponding to the second linear polarizer in the preset polarization configuration and the angle β is added to the angle to determine the first initial adjustment angle corresponding to the first half-wave plate.

[0096] By repeating the above calibration process multiple times for different magnetic field intensities, the first initial adjustment angle corresponding to the first half-wave plate under different magnetic field intensities can be determined, and then the first mapping relationship can be determined based on the first initial angle and the first initial adjustment angle corresponding to the first half-wave plate under different magnetic field intensities.

[0097] In one possible implementation, a first mapping relationship is determined based on a first initial angle and a first initial adjustment angle corresponding to the first half-wave plate under different magnetic field intensities, including: when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with a first linear polarizer and a first half-wave plate, and the collection light path is provided with a second linear polarizer and a second half-wave plate, 1 / 2 of the first initial adjustment angle corresponding to the first half-wave plate under the magnetic field intensity is determined as the first target adjustment angle corresponding to the first half-wave plate under the magnetic field intensity; and a first mapping relationship is determined based on the first initial angle and the first target adjustment angle corresponding to the first half-wave plate under different magnetic field intensities.

[0098] When the magneto-optical spectroscopy test system is in a zero magnetic field intensity, when the target excitation light enters the magnetic field through the optical element, a first polarization rotation will occur due to the Faraday rotation effect, that is, the polarization error corresponding to the target excitation light; and when the collected light leaves the magnetic field through the optical element, a second polarization rotation will occur due to the Faraday rotation effect, that is, the polarization error corresponding to the collected light.

[0099] Since, during the calibration process for the first half-wave plate, the excitation light path is provided with the first linear polarizer and the first half-wave plate, and the collection light path is provided with only the second linear polarizer, the polarization adjustment produced by the target excitation light passing through the first half-wave plate is a total compensation for the polarization error corresponding to the target excitation light and the polarization error corresponding to the collection light. As a result, the polarization angle of the excitation light incident on the magneto-optical spectroscopy test system does not meet the polarization angle corresponding to the target polarization state, affecting the normal progress of the magneto-optical spectroscopy test. This is also the reason why the target excitation light and the collection light need to be calibrated separately during the actual magneto-optical spectroscopy test process.

[0100] Typically, under the same magnetic field intensity, the polarization error caused by the Faraday rotation effect remains constant, and the optical path taken by the target excitation light after passing through the first half-wave plate and entering the magneto-optical spectroscopy testing system is the same as the optical path taken by the collected light before leaving the magneto-optical spectroscopy testing system and entering the second half-wave plate. Therefore, during a normal magneto-optical spectroscopy testing process, that is, when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with a first linear polarizer and a first half-wave plate, and the collection light path is provided with a second linear polarizer and a second half-wave plate, the first target adjustment angle corresponding to the first half-wave plate at that magnetic field intensity can be set to 1 / 2 of the first initial adjustment angle corresponding to the first half-wave plate at that magnetic field intensity, so that the polarization adjustment caused by the target excitation light passing through the first half-wave plate merely compensates for the polarization error corresponding to the target excitation light.

[0101] In one possible implementation, when the magneto-optical spectroscopy test system is in different magnetic field strengths, the second half-wave plate arranged in the collection light path is calibrated according to the reference angle, and the second mapping relationship between the angle of the second half-wave plate and the different magnetic field strengths is determined, including: when the magneto-optical spectroscopy test system is in zero magnetic field strength, and the excitation light path is only provided with the first linear polarizer, and the collection light path is provided with the second linear polarizer and the second half-wave plate, the second linear polarizer is set at the reference angle, the angle of the second half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and the second initial angle corresponding to the second half-wave plate is determined; when the magneto-optical spectroscopy test system is in any non-zero magnetic field strength, and the excitation light path is only provided with the first linear polarizer, and the collection light path is provided with the second linear polarizer and the second half-wave plate, the second linear polarizer is set at the reference angle, the angle corresponding to the second half-wave plate is adjusted until the intensity of the collected light meets the reference intensity, and the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field strength is determined; the second mapping relationship is determined based on the second initial angle and the second initial adjustment angle corresponding to the second half-wave plate under different magnetic field strengths.

[0102] When the magneto-optical spectroscopy test system is in a zero magnetic field, and only the first linear polarizer is provided in the excitation light path, and the second linear polarizer and the second half-wave plate are provided in the collection light path, the second linear polarizer is set at a reference angle, and the second half-wave plate provided in the collection light path can be calibrated to determine the second initial angle corresponding to the second half-wave plate. The specific method can be directly referred to the process of calibrating the first half-wave plate described above and will not be repeated here.

[0103] Similarly, when the magneto-optical spectroscopy test system is in any non-zero magnetic field strength, and only the first linear polarizer is provided in the excitation light path, and the second linear polarizer and the second half-wave plate are provided in the collection light path, the second linear polarizer is set at a reference angle, and the second half-wave plate provided in the collection light path can be calibrated to determine the second initial adjustment angle corresponding to the second half-wave plate. The specific method can also directly refer to the above-mentioned process of calibrating the first half-wave plate, and will not be repeated here. Among them, the second initial adjustment angle corresponding to the second half-wave plate under any magnetic field strength can represent the adjustment angle relative to the second initial angle.

[0104] By repeating the above calibration process multiple times for different magnetic field intensities, the second initial adjustment angle corresponding to the second half-wave plate under different magnetic field intensities can be determined, and then the second mapping relationship can be determined based on the second initial angle and the first initial adjustment angle corresponding to the second half-wave plate under different magnetic field intensities.

[0105] In one possible implementation, a second mapping relationship is determined based on the second initial angle and the second initial adjustment angle corresponding to the second half-wave plate under different magnetic field intensities, including: when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with a first linear polarizer and a first half-wave plate, and the collection light path is provided with a second linear polarizer and a second half-wave plate, 1 / 2 of the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity is determined as the second target adjustment angle corresponding to the second half-wave plate under the magnetic field intensity; and a second mapping relationship is determined based on the second initial angle and the second target adjustment angle corresponding to the second half-wave plate under different magnetic field intensities.

[0106] Similarly, since during the calibration process of the second half-wave plate, only the first linear polarizer is set in the excitation light path, and the second linear polarizer and the second half-wave plate are set in the collection light path, at this time, the polarization adjustment produced by the target excitation light passing through the second half-wave plate is a total compensation for the polarization error corresponding to the target excitation light and the polarization error corresponding to the collection light, resulting in the polarization angle of the collection light passing through the second half-wave plate cannot accurately reflect the true polarization state of the collection light emitted by the magneto-optical spectroscopy test system, affecting the accuracy of the test results.

[0107] Therefore, during the normal magneto-optical spectrum testing process, that is, when the magneto-optical spectrum testing system is in any non-zero magnetic field intensity, and the first linear polarizer and the first half-wave plate are set in the excitation light path, and the second linear polarizer and the second half-wave plate are set in the collection light path, the second target adjustment angle corresponding to the second half-wave plate under the magnetic field intensity can be set to 1 / 2 of the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity, so that the polarization adjustment generated by the target excitation light passing through the second half-wave plate is only a compensation for the polarization error corresponding to the collected light.

[0108] Experimental verification shows that when the magneto-optical spectroscopy test system is placed in any non-zero magnetic field strength, and the first linear polarizer and the first half-wave plate are set in the excitation light path, and the second linear polarizer and the second half-wave plate are set in the collection light path, the second target adjustment angle corresponding to the second half-wave plate under this magnetic field strength is equal in magnitude and opposite in direction to the first target adjustment angle corresponding to the first half-wave plate under this magnetic field strength. For example, under any magnetic field strength, if the first target adjustment angle corresponding to the first half-wave plate under this magnetic field strength is +θ / 2, then the second target adjustment angle corresponding to the second half-wave plate under this magnetic field strength is Among them, + indicates clockwise rotation, and - indicates counterclockwise rotation.

[0109] In a possible implementation, during the calibration process of the second linear polarizer, the first half-wave plate, and the second half-wave plate, the collected light is reflected signal light from a substrate on which a test object is placed in the magneto-optical spectroscopy test system.

[0110] Experimental verification has shown that the calibration method provided by this disclosure, when using reflected signal light from a substrate adjacent to the test object (e.g., a silicon wafer) as the collected light for calibration, produces the same calibration scheme as when using reflected signal light from a medium that does not introduce Faraday rotation, such as a gold film, as the collected light. In other words, when calibrating the same magneto-optical spectroscopy test system using the calibration method provided by this disclosure, repeated adjustments for different test objects are not required. This method has high applicability and can be widely applied in a variety of different scenarios, with promising applications in fields such as materials science, optics, and magnetism.

[0111] The specific material and form of the substrate can be flexibly set according to actual use requirements, and this disclosure does not specifically limit this. Preferably, the substrate is a medium such as a silicon wafer or a gold film placed next to the sample to be tested that does not introduce Faraday rotation.

[0112] In the disclosed embodiment, the target excitation light can be initialized by determining the angle corresponding to a first linear polarizer disposed in the excitation light path of the magneto-optical spectroscopy testing system so that the polarization angle of the target excitation light corresponding to the excitation light path is in a target polarization state. The reference angle corresponding to a second linear polarizer disposed in the collection light path of the magneto-optical spectroscopy testing system is determined to set the relationship between the polarization direction of the target excitation light and the polarization direction of the collection light corresponding to the collection light path to meet a preset polarization configuration, providing a reliable basis for the subsequent calibration process. When the magneto-optical spectroscopy test system is in different magnetic field intensities, the first half-wave plate arranged in the excitation light path is calibrated according to the reference angle, and a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities can be determined, which serves as a basis for correcting the polarization error of the target excitation light caused by the Faraday rotation effect; when the magneto-optical spectroscopy test system is in different magnetic field intensities, the second half-wave plate arranged in the collection light path is calibrated according to the reference angle, and a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities can be determined, which serves as a basis for correcting the polarization error of the collected light caused by the Faraday rotation effect; based on the first mapping relationship and the second mapping relationship, a calibration scheme for the magneto-optical spectroscopy test system under the target magnetic field intensity can be determined to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is in the target magnetic field intensity. Through the correction method of the embodiment of the present disclosure, the angle adjustment of the first linear polarizer, the second linear polarizer, the first half-wave plate, and the second half-wave plate can be used to compensate for the polarization deviation of the target excitation light and the collected light caused by the Faraday effect, thereby avoiding the accumulation of errors caused by changes in the polarization state during the magneto-optical spectroscopy test. It has high correction accuracy and stability, and does not require the customization of special optical elements. It is low-cost and easy to implement, has high applicability, can be applied to a variety of different magneto-optical spectroscopy test systems, and is suitable for different spectral test requirements. In addition, the collected light used in the correction process can directly use the reflected signal light of the substrate where the test object is placed in the magneto-optical spectroscopy test system, and does not need to be repeatedly adjusted for different samples to be tested, which can further improve applicability and reduce correction costs.

[0113] It is understood that the above-mentioned various method embodiments mentioned in this disclosure can be combined with each other to form combined embodiments without violating the principle logic. Due to space limitations, this disclosure will not go into details. It is understood by those skilled in the art that in the above-mentioned methods of specific implementation, the specific execution order of each step should be determined by its function and possible internal logic.

[0114] In addition, the present disclosure also provides a correction device for the Faraday rotation effect in magneto-optical spectroscopy testing, which can be used to implement any correction method for the Faraday rotation effect in magneto-optical spectroscopy testing provided by the present disclosure. The corresponding technical solutions and descriptions are referred to the corresponding records in the method section and will not be repeated here.

[0115] Figure 6 FIG. 1 is a block diagram of a device for correcting the Faraday rotation effect in magneto-optical spectroscopy according to an embodiment of the present disclosure. Figure 6 As shown, the apparatus 600 includes:

[0116] A first angle determination module 601 is configured to determine an angle corresponding to a first linear polarizer provided in an excitation light path of the magneto-optical spectroscopy testing system according to a target polarization state, wherein the target polarization state includes a polarization angle of a target excitation light corresponding to the excitation light path;

[0117] A second angle determination module 602 is configured to determine a reference angle corresponding to a second linear polarizer disposed in a collection light path of the magneto-optical spectroscopy testing system according to a preset polarization configuration, wherein the preset polarization configuration is configured to indicate a relationship between a polarization direction of the target excitation light and a polarization direction of the collected light corresponding to the collection light path;

[0118] A first mapping determination module 603 is configured to calibrate a first half-wave plate disposed in the excitation optical path according to a reference angle when the magneto-optical spectroscopy testing system is subjected to different magnetic field intensities, and determine a first mapping relationship between the angle of the first half-wave plate and the different magnetic field intensities;

[0119] a second mapping determination module 604 for calibrating a second half-wave plate disposed in the collection optical path according to a reference angle when the magneto-optical spectroscopy testing system is subjected to different magnetic field intensities, and determining a second mapping relationship between the angle of the second half-wave plate and the different magnetic field intensities;

[0120] The calibration scheme determination module 605 is used to determine the calibration scheme of the magneto-optical spectroscopy test system under the target magnetic field strength based on the first mapping relationship and the second mapping relationship, wherein the calibration scheme is used to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is under the target magnetic field strength.

[0121] In one possible implementation, the second angle determination module 602 is specifically used to: determine a third mapping relationship when only a first linear polarizer is set in the excitation light path and only a second linear polarizer is set in the collection light path, wherein the third mapping relationship is used to indicate the intensity of the collected light when the second linear polarizer is at different angles; and determine a reference angle based on the reference intensity of the collected light under a preset polarization configuration and the third mapping relationship.

[0122] In one possible implementation, the first mapping determination module 603 is specifically used to: when the magneto-optical spectroscopy test system is in a zero magnetic field intensity, and the first linear polarizer and the first half-wave plate are set in the excitation light path, and only the second linear polarizer is set in the collection light path, set the second linear polarizer at a reference angle, adjust the angle of the first half-wave plate until the intensity of the collected light meets the reference intensity, and determine the first initial angle corresponding to the first half-wave plate; when the magneto-optical spectroscopy test system is in any non-zero magnetic field intensity, and the first linear polarizer and the first half-wave plate are set in the excitation light path, and only the second linear polarizer is set in the collection light path, set the second linear polarizer at a reference angle, adjust the angle corresponding to the first half-wave plate until the intensity of the collected light meets the reference intensity, and determine the first initial adjustment angle corresponding to the first half-wave plate under the magnetic field intensity; determine the first mapping relationship based on the first initial angle and the first initial adjustment angle corresponding to the first half-wave plate under different magnetic field intensities.

[0123] In one possible implementation, the first mapping determination module 603 is also used to: when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with a first linear polarizer and a first half-wave plate, and the collection light path is provided with a second linear polarizer and a second half-wave plate, 1 / 2 of the first initial adjustment angle corresponding to the first half-wave plate under the magnetic field intensity is determined as the first target adjustment angle corresponding to the first half-wave plate under the magnetic field intensity; determine the first mapping relationship based on the first initial angle and the first target adjustment angle corresponding to the first half-wave plate under different magnetic field intensities.

[0124] In one possible implementation, the second mapping determination module 604 is specifically used to: when the magneto-optical spectroscopy test system is in a zero magnetic field intensity, and only the first linear polarizer is set in the excitation light path, and the second linear polarizer and the second half-wave plate are set in the collection light path, set the second linear polarizer at a reference angle, adjust the angle of the second half-wave plate until the intensity of the collected light meets the reference intensity, and determine the second initial angle corresponding to the second half-wave plate; when the magneto-optical spectroscopy test system is in any non-zero magnetic field intensity, and only the first linear polarizer is set in the excitation light path, and the second linear polarizer and the second half-wave plate are set in the collection light path, set the second linear polarizer at a reference angle, adjust the angle corresponding to the second half-wave plate until the intensity of the collected light meets the reference intensity, and determine the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity; determine the second mapping relationship based on the second initial angle and the second initial adjustment angle corresponding to the second half-wave plate under different magnetic field intensities.

[0125] In one possible implementation, the second mapping determination module 604 is also used to: when the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with a first linear polarizer and a first half-wave plate, and the collection light path is provided with a second linear polarizer and a second half-wave plate, 1 / 2 of the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity is determined as the second target adjustment angle corresponding to the second half-wave plate under the magnetic field intensity; determine the second mapping relationship according to the second initial angle and the second target adjustment angle corresponding to the second half-wave plate under different magnetic field intensities.

[0126] In a possible implementation, the intensity of the collected light is determined by a power meter disposed behind the second linear polarizer.

[0127] In a possible implementation, the preset polarization configuration includes: the polarization direction corresponding to the target excitation light is parallel to the polarization direction corresponding to the collected light, or the polarization direction corresponding to the target excitation light is perpendicular to the polarization direction corresponding to the collected light.

[0128] In a possible implementation, during the calibration process of the second linear polarizer, the first half-wave plate, and the second half-wave plate, the collected light is reflected signal light from a substrate on which a test object is placed in the magneto-optical spectroscopy test system.

[0129] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0130] While various embodiments of the present disclosure have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for correcting the Faraday rotation effect in magneto-optical spectroscopy, characterized in that: include: Determining an angle corresponding to a first linear polarizer disposed in an excitation light path of the magneto-optical spectroscopy testing system according to a target polarization state, wherein the target polarization state includes a polarization angle of a target excitation light corresponding to the excitation light path; Determining a reference angle corresponding to a second linear polarizer disposed in a collection light path of the magneto-optical spectroscopy testing system according to a preset polarization configuration, wherein the preset polarization configuration is used to indicate a relationship between a polarization direction of the target excitation light and a polarization direction of the collection light corresponding to the collection light path, and the preset polarization configuration includes: the polarization direction corresponding to the target excitation light is parallel to the polarization direction corresponding to the collection light, or the polarization direction corresponding to the target excitation light is perpendicular to the polarization direction corresponding to the collection light; When the magneto-optical spectroscopy testing system is subjected to different magnetic field intensities, calibrating the first half-wave plate provided in the excitation optical path according to the reference angle to determine a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities; When the magneto-optical spectroscopy testing system is subjected to different magnetic field intensities, calibrating the second half-wave plate provided in the collection light path according to the reference angle to determine a second mapping relationship between the angle of the second half-wave plate and the different magnetic field intensities; Based on the first mapping relationship and the second mapping relationship, a calibration scheme of the magneto-optical spectroscopy testing system under the target magnetic field strength is determined, wherein the calibration scheme is used to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy testing system is under the target magnetic field strength.

2. The method according to claim 1, characterized in that The step of determining a reference angle corresponding to a second linear polarizer disposed in a light collection path of the magneto-optical spectrum testing system according to a preset polarization configuration includes: When only the first linear polarizer is provided in the excitation light path and only the second linear polarizer is provided in the collection light path, determining a third mapping relationship, wherein the third mapping relationship is used to indicate the intensity of the collected light when the second linear polarizer is at different angles; The reference angle is determined according to the reference light intensity of the collected light under the preset polarization configuration and the third mapping relationship.

3. The method according to claim 2, characterized in that The method of calibrating a first half-wave plate provided in the excitation optical path according to the reference angle when the magneto-optical spectroscopy testing system is subjected to different magnetic field intensities, and determining a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities, includes: When the magneto-optical spectroscopy testing system is in a zero magnetic field intensity, the excitation light path is provided with the first linear polarizer and the first half-wave plate, and the collection light path is provided with only the second linear polarizer, the second linear polarizer is set at the reference angle, the angle of the first half-wave plate is adjusted until the intensity of the collected light meets the reference light intensity, and a first initial angle corresponding to the first half-wave plate is determined; When the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with the first linear polarizer and the first half-wave plate, and the collection light path is provided with only the second linear polarizer, the second linear polarizer is set at the reference angle, the angle corresponding to the first half-wave plate is adjusted until the intensity of the collected light meets the reference light intensity, and a first initial adjustment angle corresponding to the first half-wave plate under the magnetic field intensity is determined; The first mapping relationship is determined according to the first initial angle and the first initial adjustment angles corresponding to the first half-wave plate under different magnetic field intensities.

4. The method according to claim 3, characterized in that The determining the first mapping relationship according to the first initial angle and the first initial adjustment angle corresponding to the first half-wave plate under different magnetic field intensities includes: When the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with the first linear polarizer and the first half-wave plate, and the collection light path is provided with the second linear polarizer and the second half-wave plate, half of a first initial adjustment angle corresponding to the first half-wave plate under the magnetic field intensity is determined as a first target adjustment angle corresponding to the first half-wave plate under the magnetic field intensity; The first mapping relationship is determined according to the first initial angle and a first target adjustment angle corresponding to the first half-wave plate under different magnetic field intensities.

5. The method according to claim 2, characterized in that The method of calibrating the second half-wave plate provided in the collecting light path according to the reference angle when the magneto-optical spectroscopy testing system is in different magnetic field intensities, and determining a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities, includes: When the magneto-optical spectroscopy testing system is in a zero magnetic field intensity, and only the first linear polarizer is provided in the excitation light path, and the second linear polarizer and the second half-wave plate are provided in the collection light path, the second linear polarizer is set at the reference angle, the angle of the second half-wave plate is adjusted until the intensity of the collected light meets the reference light intensity, and a second initial angle corresponding to the second half-wave plate is determined; When the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with only a first linear polarizer, and the collection light path is provided with a second linear polarizer and a second half-wave plate, the second linear polarizer is set at the reference angle, the angle corresponding to the second half-wave plate is adjusted until the intensity of the collected light meets the reference light intensity, and a second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity is determined; The second mapping relationship is determined according to the second initial angle and the second initial adjustment angles corresponding to the second half-wave plate under different magnetic field intensities.

6. The method according to claim 5, characterized in that The determining the second mapping relationship according to the second initial angle and the second initial adjustment angle corresponding to the second half-wave plate under different magnetic field intensities includes: When the magneto-optical spectroscopy testing system is in any non-zero magnetic field intensity, and the excitation light path is provided with the first linear polarizer and the first half-wave plate, and the collection light path is provided with the second linear polarizer and the second half-wave plate, half of the second initial adjustment angle corresponding to the second half-wave plate under the magnetic field intensity is determined as the second target adjustment angle corresponding to the second half-wave plate under the magnetic field intensity; The second mapping relationship is determined according to the second initial angle and the second target adjustment angle corresponding to the second half-wave plate under different magnetic field intensities.

7. The method according to any one of claims 2 to 6, characterized in that The intensity of the collected light is determined by a power meter disposed behind the second linear polarizer.

8. The method according to any one of claims 1 to 6, characterized in that During the calibration process of the second linear polarizer, the first half-wave plate, and the second half-wave plate, the collected light is the reflected signal light of the substrate on which the test object is placed in the magneto-optical spectroscopy test system.

9. A correction device for the Faraday rotation effect in magneto-optical spectroscopy, characterized in that: include: A first angle determination module is configured to determine an angle corresponding to a first linear polarizer provided in an excitation light path of the magneto-optical spectroscopy testing system according to a target polarization state, wherein the target polarization state includes a polarization angle of a target excitation light corresponding to the excitation light path; a second angle determination module, configured to determine a reference angle corresponding to a second linear polarizer disposed in a collection light path of the magneto-optical spectroscopy testing system according to a preset polarization configuration, wherein the preset polarization configuration is configured to indicate a relationship between a polarization direction of the target excitation light and a polarization direction of the collected light corresponding to the collection light path, and the preset polarization configuration includes: a polarization direction corresponding to the target excitation light and a polarization direction corresponding to the collected light being parallel, or a polarization direction corresponding to the target excitation light and a polarization direction corresponding to the collected light being perpendicular; a first mapping determination module, configured to calibrate a first half-wave plate provided in the excitation optical path according to the reference angle when the magneto-optical spectroscopy testing system is subjected to different magnetic field intensities, and determine a first mapping relationship between the angle of the first half-wave plate and different magnetic field intensities; a second mapping determination module, configured to calibrate a second half-wave plate provided in the collection light path according to the reference angle when the magneto-optical spectroscopy testing system is subjected to different magnetic field intensities, and determine a second mapping relationship between the angle of the second half-wave plate and different magnetic field intensities; A calibration scheme determination module is used to determine the calibration scheme of the magneto-optical spectroscopy test system under the target magnetic field strength based on the first mapping relationship and the second mapping relationship, wherein the calibration scheme is used to indicate the angles of the first half-wave plate and the second half-wave plate when the magneto-optical spectroscopy test system is under the target magnetic field strength.

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