JP2013137209A - Polarization change spectrum measuring device, polarization change spectrum measuring method, magneto-optical effect measuring device and magneto-optical effect measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a time required for measuring wavelength dependence of an angle change of a plane of polarization in a material.SOLUTION: A magneto-optical effect measuring device 10 comprises: a white light source 1 for generating white light; a polarizer 2 for forming linearly polarized light from the white light and making the linearly polarized light incident on a sample S; an electromagnet for applying a magnetic field to the sample S; an analyzer 5 on which detection light emitted from the sample S is made incident; a spectrometer 7 on which a passed light passed through the analyzer 5 is made incident; an optical sensor 8 for detecting respective light intensities of wavelength components with different wavelengths obtained by splitting light by the spectrometer 7; and an arithmetic unit 9 for calculating wavelength dependence of magneto-optical characteristics of the sample S from respective light intensities of the detected wavelength components.

Description

  The present invention relates to a polarization change spectrum measuring apparatus, a polarization change spectrum measuring method, a magneto-optical effect measuring apparatus and a magneto-optical effect measuring method using the same, and more particularly to an apparatus for measuring the wavelength dependence of polarization change in a substance. And a method.

  There are various causes for causing a change in the angle of the polarization plane in a material. For example, magneto-optical effects such as the Faraday effect and the magneto-optical Kerr effect are one of such causes. Magneto-optical effects such as the Faraday effect and the magneto-optical Kerr effect are used in various optical devices and magnetic devices such as optical isolators, current / magnetic field sensors, and magneto-optical recording apparatuses. When designing and manufacturing optical devices and magnetic devices that use the magneto-optical effect, measure the magneto-optical properties of the materials used (for example, the Verde constant for the Faraday effect and the Kerr constant for the magneto-optical Kerr effect). For this purpose, it is required to measure the change in the angle of the polarization plane in the material.

  FIG. 1 shows a typical configuration of the magneto-optical effect measuring apparatus 100. The magneto-optical effect measuring apparatus 100 is configured to measure the Verde constant of the sample S, and includes a variable wavelength light source 101, a polarizer 102, an electromagnet 103, an excitation power source 104, an analyzer 105, and a drive circuit. 106, a photoelectric converter 107, an amplifier 108, and an arithmetic device 109.

  The variable wavelength light source 101 is a light source that generates light having a wavelength specified by the arithmetic unit 109, and includes a white light source 101a, a spectroscope 101b, and slits 101c and 101d. The white light source 101a enters white light into the spectroscope 101b through the slit 101c. The spectroscope 101b separates the incident white light and spatially disperses each wavelength component of the white light at a position corresponding to the wavelength. The slit 101d is configured such that its position is movable, and light having a wavelength designated by the arithmetic unit 109 is emitted from the spectroscope 101b by controlling the position of the slit 101d.

  The light emitted from the spectroscope 101b passes through the polarizer 102 and enters the sample S. As a result, only linearly polarized light having a predetermined plane of polarization is incident on the sample S. A magnetic field is applied to the sample S by the electromagnet 103. When incident light (linearly polarized light) with a magnetic field applied passes through the sample S, the angle of the polarization plane rotates due to the Faraday effect. The light emitted from the sample S enters the analyzer 105. The analyzer 105 can adjust the angle of the analyzer 105 (strictly speaking, the angle of the transmission axis of the analyzer 105) by the driving device 106, and the light intensity of the light passing through the analyzer 105 is determined by the analyzer 105. Depends on the angle. The light that has passed through the analyzer 105 is incident on the photoelectric converter 107. The output signal of the photoelectric converter 107 is input to the amplifier 108 and amplified. Based on the output signal of the amplifier 108, the arithmetic unit 109 detects the light intensity of the light that has passed through the analyzer 105.

The Verde constant is measured by the magneto-optical effect measuring apparatus 100 of FIG. 1 as follows. Light is incident on the sample S through the polarizer 102 with the magnetic field H applied by the electromagnet 103. The light emitted from the sample S (with the polarization plane rotated) is incident on the analyzer 105. The analyzer 105 is rotated in a state where the light emitted from the sample S is incident on the analyzer 105, and the angle of the analyzer 105 that minimizes the light intensity of the light that has passed through the analyzer 105 is detected. Angle and the difference in angle of the polarizer 102 of the analyzer 105 to the light intensity of the light passed through the analyzer 105 and the minimum is identified as a Faraday rotation angle theta _F, and the Faraday rotation angle theta _F, thickness of the sample S From d and the magnetic field H, the Verde constant V is calculated from the following equation (1):
V = θ _F / Hd (1)

  The magneto-optical effect measuring apparatus as shown in FIG. 1 is disclosed in, for example, Japanese Patent Laid-Open Nos. 09-280953, 11-101735, 11-101736, 11-101737, 11-11. No. 101738.

  Here, if the wavelength dependence of the Verde constant is to be measured using a measuring apparatus as shown in FIG. 1, the analyzer 105 for each wavelength while sequentially switching the wavelength of light incident on the sample S by the spectroscope 101b. It is necessary to perform rotation. Such a measurement procedure is not preferable because a long measurement time is required.

  Such a problem is applicable not only when measuring the wavelength dependence of the Verde constant, but also when measuring the wavelength dependence of the change in the angle of the polarization plane in the material.

JP 09-280953 A JP-A-11-101735 Japanese Patent Application Laid-Open No. 11-101736 JP-A-11-101737 Japanese Patent Laid-Open No. 11-101738

  Therefore, an object of the present invention is to provide a technique for shortening the time required for measuring the wavelength dependence of the change in the angle of the polarization plane in a substance.

  In one aspect of the present invention, a polarization change spectrum measuring apparatus includes: a light source that generates multicolor light having wavelength components of a plurality of wavelengths; a polarizer that generates linearly polarized light from the multicolored light and that inputs linearly polarized light into a sample; The light intensity of each of the wavelength components of a plurality of wavelengths obtained by the spectroscope by the spectroscope to which the detection light emitted from the sample is incident, the spectroscope to which the passing light that has passed through the analyzer is incident, and A light detecting means for detecting, and an arithmetic device for calculating the wavelength dependence of the change in the angle of the polarization plane of the linearly polarized light by the sample from the light intensity of each of the wavelength components detected in a state in which the magnetic field is applied to the sample. To do.

  In another aspect of the present invention, a magneto-optical effect measuring apparatus generates a light source that generates multicolor light having wavelength components of a plurality of wavelengths, probe light that is linearly polarized light from the multicolored light, and makes linearly polarized light incident on a sample. , A magnetic field applying unit that applies a magnetic field to the sample, an analyzer that receives detection light emitted from the sample, a spectroscope that receives light passing through the analyzer, and spectroscopy by the spectroscope And a calculation unit for calculating the wavelength dependence of the magneto-optical characteristic of the sample from the respective light intensities of the detected wavelength components. To do. According to such a magneto-optical effect measuring apparatus, since the magneto-optical characteristics of a plurality of wavelengths can be measured simultaneously, the time required for measuring the wavelength dependence of the magneto-optical characteristics can be shortened.

  In one embodiment, the light intensity of each wavelength component obtained by spectroscopy with a spectroscope is measured while changing the analyzer angle, which is the angle of the transmission axis of the analyzer. In this case, the arithmetic unit generates angle-light intensity data indicating the relationship between the analyzer angle and the light intensity for each of a plurality of wavelengths from each light intensity of the wavelength component, and samples from the angle-light intensity data. The rotation angle of the polarization plane at is calculated, and the wavelength dependence of the magneto-optical characteristics of the sample is calculated from the calculated rotation angle.

  In another embodiment, the light intensity of each wavelength component obtained by spectroscopy by a spectroscope is the light intensity of each wavelength component in a state where the analyzer angle, which is the angle of the transmission axis of the analyzer, is fixed. Measured. Further, rotation angle-light intensity change data indicating the relationship between the rotation angle of the polarization plane in the sample and the change in the light intensity of each wavelength component is prepared in advance in the arithmetic unit. In this case, the arithmetic unit calculates the rotation angle of the polarization plane in the sample from each light intensity of the wavelength component using the stored rotation angle-light intensity change data, and the magneto-optical characteristics of the sample from the calculated rotation angle. The wavelength dependence of is calculated.

  In one embodiment, rotation angle-light intensity change data is generated as data indicating a change in light intensity of each wavelength component per unit angle of the rotation angle of the polarization plane in the sample. The arithmetic unit calculates the difference between the light intensity of each wavelength component detected when a magnetic field is applied to the sample and the light intensity of each wavelength component detected when no magnetic field is applied to the sample, and the rotation angle − The rotation angle of the polarization plane in the sample is calculated from the light intensity change data.

  In this case, the detection of the light intensity of each wavelength component with a magnetic field applied to the sample is performed when the angle of the transmission axis of the polarizer and the angle of the transmission axis of the analyzer are not rotated in the polarization plane of the sample. It is preferable that the angle formed between the plane of polarization of the linearly polarized light incident on the analyzer and the transmission axis of the analyzer is in the range of 43 ° to 47 °.

  In another embodiment, the computing device may be configured such that the light intensity of each wavelength component detected in a state where the first magnetic field is applied to the sample in the first direction and the sample in the second direction opposite to the first direction. The rotation angle of the polarization plane of the sample is calculated from the difference between the light intensity of each of the wavelength components detected in a state where the second magnetic field having the same magnitude as the first magnetic field is not applied and the rotation angle-light intensity change data. To do.

  In still another embodiment, the magneto-optical effect measurement apparatus further includes a Faraday cell provided in series with a polarizer between the light source and the sample, and a drive that supplies a drive current that is an AC periodic signal to the Faraday cell. And a timing control means for controlling the operation timing of the driving circuit and the optical sensor so that the timing at which the optical sensor measures the light intensity of each wavelength component is synchronized with the driving current supplied to the Faraday cell.

  In this case, the rotation angle-light intensity change data is the difference in light intensity of each of the wavelength components at the first and second timings defined for each period of the drive current per unit angle of the rotation angle of the polarization plane of the sample. It is prepared as data indicating. Here, the first timing and the second timing are determined so that the light intensity of each of the wavelength components detected by the optical sensor has a different maximum value in each cycle of the drive current when the polarization plane rotates in the sample. It has been. The arithmetic device calculates the difference between the light intensity of each of the wavelength components at the first timing and the light intensity of each of the wavelength components at the second timing detected with the magnetic field applied to the sample, and the rotation angle-light intensity change. The rotation angle of the polarization plane in the sample is calculated from the data.

  In this case, the detection of the light intensity of each wavelength component with a magnetic field applied to the sample is performed when the angle of the transmission axis of the polarizer and the angle of the transmission axis of the analyzer are not rotated in the polarization plane of the sample. It is preferable that the angle formed between the plane of polarization of the linearly polarized light incident on the analyzer and the transmission axis of the analyzer is adjusted so as to be in the range of 43 ° to 47 °.

  In the magneto-optical effect measuring apparatus, the light detecting means is preferably an area sensor.

  In the magneto-optical effect measuring apparatus, when calculating the wavelength dependence of the Verde constant of the sample, the analyzer, the spectroscope, and the light detecting means are arranged so that light transmitted through the sample is incident on the analyzer. Is done. When calculating the wavelength dependence of the Kerr constant of the sample, the analyzer, the spectroscope, and the light detection means are arranged so that the light reflected from the sample is incident on the analyzer.

  In yet another aspect of the present invention, a light source that generates multicolor light having wavelength components of a plurality of wavelengths, a polarizer that generates linearly polarized light from the multicolored light, and enters the sample with linearly polarized light, and a magnetic field applied to the sample Polarization spectrum measurement for calculating the wavelength dependence of the change in the angle of the plane of polarization of linearly polarized light by the sample by a polarization change spectrum measuring device comprising a magnetic field applying means for performing detection and an analyzer for receiving detection light emitted from the sample A method is provided. The polarization change spectrum measurement method includes entering light passing through an analyzer into a spectroscope, detecting each light intensity of wavelength components of a plurality of wavelengths obtained by spectroscopy by the spectroscope, Calculating the wavelength dependence of the change in the angle of the polarization plane of the linearly polarized light by the sample from the light intensity of each of the wavelength components detected in a state where a magnetic field is applied.

  In yet another aspect of the present invention, a light source that generates multicolor light having wavelength components of a plurality of wavelengths, a polarizer that generates linearly polarized light from the multicolored light, and enters the sample with linearly polarized light, and a magnetic field applied to the sample There is provided a magneto-optical effect measuring method for calculating the wavelength dependence of the magneto-optical characteristics of a sample by a magneto-optical effect measuring apparatus comprising a magnetic field applying means for performing the above and an analyzer for receiving detection light emitted from the sample. The magneto-optical effect measurement method includes entering light passing through an analyzer into a spectrometer, detecting each light intensity of wavelength components of a plurality of wavelengths obtained by spectroscopy by the spectrometer, Calculating the wavelength dependence of the magneto-optical characteristics of the sample from the light intensities of the wavelength components detected in a state where a magnetic field is applied.

  According to the present invention, the time required for measuring the wavelength dependence of the magneto-optical characteristic can be shortened.

It is a block diagram which shows the structure of a typical magneto-optical effect measuring apparatus. It is a block diagram which shows the structure of the magneto-optical effect measuring apparatus of the 1st Embodiment of this invention. It is a flowchart which shows the measurement procedure of the Verde constant in 1st Embodiment. It is a graph which shows notionally the contents of background data measured in a 1st embodiment. It is a graph which shows notionally the contents of spectrum data measured in a 1st embodiment. It is a graph which shows notionally the contents of angle-light intensity data measured in a 1st embodiment. It is a graph which shows the method of the data fitting for calculation of Faraday rotation angle in 1st Embodiment. It is a graph which shows the other method of the data fitting for calculation of Faraday rotation angle in 1st Embodiment. It is a graph which shows the method of calculating the Verde constant from the relationship between a magnetic field and a Faraday rotation angle in 1st Embodiment. It is a figure which shows the example of the shape of the light spot formed in the surface of the optical sensor 8 when an area sensor is used as the optical sensor 8. FIG. It is a figure which shows the other example of the shape of the light spot formed in the surface of the optical sensor 8 when an area sensor is used as the optical sensor 8. FIG. It is a block diagram which shows the structure of the magneto-optical effect measuring apparatus of the 2nd Embodiment of this invention. It is a flowchart which shows the measurement procedure of the Verde constant in 2nd Embodiment. It is a graph which shows the relationship between a polarizer angle and light intensity in the prior spectrum measurement of 2nd Embodiment. It is a graph which shows notionally the contents of spectrum data obtained in prior spectrum measurement of a 2nd embodiment. It is a graph which shows notionally wavelength dependence alpha (lambda) of change rate of light intensity I per Faraday rotation angle 1 degree obtained in prior spectrum measurement of a 2nd embodiment. It is a graph which shows notionally the method of calculating Faraday rotation angle from spectrum data in a 2nd embodiment. It is a graph which shows the relationship between a polarizer angle and light intensity in the prior spectrum measurement of 2nd Embodiment. It is a graph which shows notionally the contents of spectrum data obtained in prior spectrum measurement of a 2nd embodiment. It is a graph which shows notionally wavelength dependence alpha (lambda) of change rate of light intensity I per Faraday rotation angle 1 degree obtained in prior spectrum measurement of a 2nd embodiment. It is a flowchart which shows the measurement procedure of the Verde constant in the modification of 2nd Embodiment. It is a block diagram which shows the structure of the magneto-optical effect measuring apparatus of the 3rd Embodiment of this invention. It is a graph which shows the principle of the measurement of the Verde constant in 3rd Embodiment. In the third embodiment, a flow chart illustrating timings A per Faraday rotation angle 1 °, the light intensity I _A in _B, the wavelength dependency of the difference between I _B beta steps to create data representing a (lambda). Timing A in the third embodiment, the light intensity at B I _A, is a graph conceptually showing wavelength dependency β a (lambda) of the difference between I _B. It is a flowchart which shows the measurement procedure of the Verde constant in 3rd Embodiment. It is a graph which shows notionally the method of calculating Faraday rotation angle from spectrum data in a 3rd embodiment. It is a block diagram which shows the modification of a structure of the magneto-optical effect measuring apparatus of the 3rd Embodiment of this invention. It is a block diagram which shows the structure which changed the magneto-optical effect measuring apparatus of 1st Embodiment so that it might correspond to the Kerr constant measurement about a pole Kerr effect. It is a block diagram which shows the structure which changed the magneto-optical effect measuring apparatus of 1st Embodiment so that it might respond | correspond to the measurement of a longitudinal Kerr effect Kerr constant. It is a block diagram which shows the structure which changed the magneto-optical effect measuring apparatus of 2nd Embodiment so that it might correspond to the Kerr constant measurement about a pole Kerr effect. It is a block diagram which shows the structure which changed the magneto-optical effect measuring apparatus of 2nd Embodiment so that it might respond | correspond to the measurement of a longitudinal Kerr effect Kerr constant. It is a block diagram which shows the structure which changed the magneto-optical effect measuring apparatus of 3rd Embodiment so that it might correspond to the Kerr constant measurement about a pole Kerr effect. It is a block diagram which shows the structure which changed the magneto-optical effect measuring apparatus of 3rd Embodiment so that it might respond | correspond to the measurement of a longitudinal Kerr effect Kerr constant. It is a block diagram which shows the structure of the polarization | polarized-light change spectrum measuring apparatus which changed the magneto-optical effect measuring apparatus of 1st Embodiment corresponding to the measurement of the temperature dependence of the change (rotation angle) of the angle of a polarization plane. It is a block diagram which shows the structure of the polarization | polarized-light change spectrum measuring apparatus which changed the magneto-optical effect measuring apparatus of 2nd Embodiment so that it might respond | correspond to the temperature dependence measurement of the angle change (rotation angle) of a polarization plane. It is a block diagram which shows the structure of the polarization | polarized-light change spectrum measuring apparatus which changed the magneto-optical effect measuring apparatus of 3rd Embodiment so that it might respond to the measurement of the temperature dependence of the change (rotation angle) of the angle of a polarization plane. It is a block diagram which shows the structure of the polarization | polarized-light change spectrum measuring apparatus which changed the magneto-optical effect measuring apparatus of 1st Embodiment so that it might respond | correspond to the measurement of the pressure dependence of the change (rotation angle) of a polarization plane. It is a block diagram which shows the structure of the polarization | polarized-light change spectrum measuring apparatus which changed the magneto-optical effect measuring apparatus of 2nd Embodiment so that it might correspond to the measurement of the pressure dependence of the change (rotation angle) of the angle of a polarization plane. It is a block diagram which shows the structure of the polarization change spectrum measuring apparatus which changed the magneto-optical effect measuring apparatus of 3rd Embodiment so that it might correspond to the measurement of the pressure dependence of the change (rotation angle) of the angle of a polarization plane. A configuration showing a configuration of a polarization change spectrum measurement device in which the magneto-optical effect measurement device according to the first embodiment is changed so as to correspond to the measurement of the voltage dependency or current dependency of the change (rotation angle) of the polarization plane angle. FIG. A configuration showing a configuration of a polarization change spectrum measurement device in which the magneto-optical effect measurement device according to the second embodiment is changed to correspond to the measurement of the voltage dependence or current dependence of the change (rotation angle) of the polarization plane angle. FIG. A configuration showing a configuration of a polarization change spectrum measurement device in which the magneto-optical effect measurement device according to the third embodiment is changed to correspond to the measurement of the voltage dependence or current dependence of the change (rotation angle) of the polarization plane angle. FIG.

First embodiment:
FIG. 2 is a configuration diagram showing the configuration of the magneto-optical effect measuring apparatus 10 according to the first embodiment of the present invention. The magneto-optical effect measuring apparatus 10 is configured to measure the Verde constant of the sample S. The white light source 1, the polarizer 2, the electromagnet 3, the excitation power source 4, the analyzer 5, and the drive circuit 6 are configured. A spectroscope 7, an optical sensor 8, and an arithmetic device 9.

  The white light source 1 generates white light and makes the generated white light enter the polarizer 2. The polarizer 2 generates linearly polarized light by passing a light component having a polarization plane at a specific angle in the incident white light. The generated linearly polarized light is incident on the sample S. Here, in this embodiment, the angle of the polarizer 2 (strictly speaking, the angle of the transmission axis of the polarizer 2) is defined as 0 °.

  The electromagnet 3 applies a magnetic field H to the sample S. In this embodiment in which the Verde constant is measured, the magnetic field H is applied in a direction (same direction or reverse direction) parallel to the propagation direction of the linearly polarized light incident on the sample S. As will be described later, when the linearly polarized light incident from the polarizer 2 passes through the sample S with the magnetic field H applied, the polarization plane of the linearly polarized light in the sample S is rotated by the Faraday effect. The linearly polarized light emitted from the sample S enters the analyzer 5.

  The excitation power supply 4 supplies an excitation current to the electromagnet 3. The strength of the magnetic field H applied to the sample S is controlled by the magnitude of the excitation current. The magnitude of the excitation current generated by the excitation power supply 4, that is, the strength of the magnetic field H applied to the sample S is controlled by the arithmetic unit 9.

  The analyzer 5 allows light components having a polarization plane of a specific angle among the linearly polarized light emitted from the sample S to pass therethrough. The passing light that has passed through the analyzer 5 enters the spectrometer 7. The analyzer 5 is provided with a rotation mechanism 5a, and the angle of the analyzer 5 (strictly speaking, the angle of the transmission axis of the analyzer 5) can be adjusted. Hereinafter, the angle of the analyzer 5 is simply referred to as an analyzer angle θ. However, when the angle of the transmission axis of the polarizer 2 and the angle of the transmission axis of the analyzer 5 coincide with each other, the analyzer angle θ is defined as 0 °.

  The drive circuit 6 drives the rotation mechanism 5 a of the analyzer 5. The drive circuit 6 is controlled by the arithmetic unit 9. That is, the angle of the analyzer 5 is controlled by the arithmetic unit 9.

  The spectroscope 7 spatially disperses each wavelength component of the passing light that has passed through the analyzer 5 at a position corresponding to the wavelength. Here, it should be noted that the light incident on the spectrometer 7 is white light.

  The optical sensor 8 measures the light intensity of each wavelength component obtained by spectroscopy by the spectrometer 7. Here, as the optical sensor 8, a line sensor (that is, an array of one-dimensionally arranged photodetectors) or an area sensor (that is, an array of two-dimensionally arranged photodetectors) is used. Since wavelength components of different wavelengths are emitted from different positions of the spectrometer 7, the light intensity of the wavelength components of different wavelengths can be measured simultaneously by using a line sensor or an area sensor.

  The arithmetic unit 9 calculates the Verde constant at each wavelength, that is, the wavelength dependence of the Verde constant, from the light intensity of each wavelength component measured by the optical sensor 8. The arithmetic device 9 further controls each device (for example, the excitation power source 4 and the drive circuit 6) of the magneto-optical effect measuring device 10.

  FIG. 3 is a flowchart illustrating a procedure for measuring the Verde constant of the sample S by the magneto-optical effect measuring apparatus 10 according to the first embodiment.

First, background data is acquired (step S01). The background data is data indicating the light intensity of light incident on the optical sensor 8 with the white light source 1 turned off, and is external light noise data of the magneto-optical effect measuring apparatus 10. Specifically, the light intensity of each wavelength component is measured by the optical sensor 8 while changing the analyzer angle θ in a predetermined angular increment (for example, in increments of 0.5 °) with the white light source 1 turned off. The The measured light intensity of each wavelength component is stored in the arithmetic unit 9 as background data. FIG. 4 is a graph conceptually showing the contents of the acquired background data. The horizontal axis represents the wavelength λ, and the vertical axis represents the light intensity I. The background data is generated as data indicating the relationship between the wavelength λ and the light intensity I for each analyzer angle θ. The background data regarding the analyzer angle θ is hereinafter referred to as I ^BG _θ (λ).

  Subsequently, measurement is performed while causing the Faraday effect in the sample S. Specifically, first, the magnetic field H applied to the sample S is set to a desired value (step S02). The magnetic field H is controlled by controlling the excitation current supplied from the excitation power supply 4 to the electromagnet 3.

  Further, the analyzer angle θ is set to a desired angle (step S03). Initially, the analyzer angle θ is set to 0 ° in step S03.

  Subsequently, spectrum data is acquired (step S04). The spectrum data is data indicating the relationship between the wavelength λ of light incident on the optical sensor 8 and the light intensity I. Specifically, the white light source 1 is turned on, and linearly polarized light that is white light is incident on the sample S from the polarizer 2. As a result, the light that has passed through the analyzer 5 out of the linearly polarized light that has passed through the sample S enters the spectroscope 7, and each wavelength component that has entered the spectroscope 7 is a photosensor at a position corresponding to the wavelength of the light. 8 is incident. Furthermore, the optical sensor 8 measures the light intensity of each wavelength component of the incident light. Thereby, spectral data indicating the relationship between the wavelength λ of the light incident on the optical sensor 8 and the light intensity I is acquired for the magnetic field H set in step S02 and the analyzer angle θ set in step S03. The

  The steps S03 and S04 described above are repeated while sequentially increasing the analyzer angle θ by a predetermined angle unit (for example, 0.5 °). That is, if the analyzer angle θ measured in step S04 is the end angle (180 ° in the present embodiment), the measurement procedure proceeds to step S06, and if not, the analyzer angle in step S03. After increasing θ by a predetermined angular step, the spectrum data is acquired again in step S04 (step S05). Thereby, with respect to the magnetic field H set in step S02, spectral data indicating the relationship between the wavelength λ of light incident on the optical sensor 8 and the light intensity I when the angle of the analyzer 5 is used as a parameter is acquired.

FIG. 5 is a diagram conceptually showing the contents of the obtained spectrum data. The horizontal axis represents the wavelength λ, and the vertical axis represents the light intensity I. Hereinafter, spectral data obtained for a certain magnetic field H and a certain analyzer angle θ may be described as I _{H, θ} (λ).

Here, linearly polarized emitted from the sample S is the plane of polarization of an angle different from the linearly polarized light incident on the sample S by the Faraday effect, in particular, has the polarization plane of the angle of Faraday rotation angle theta _F . Therefore, when the analyzer angle θ is 90 ° with the plane of polarization of the linearly polarized light emitted from the sample S, the light intensity I of the light incident on the optical sensor 8 is minimized. However, since the Faraday rotation angle θ _F varies depending on the wavelength, the analyzer angle θ _MIN that minimizes the light intensity I of the light incident on the optical sensor 8 also varies depending on the wavelength.

  The above steps S02 to S05 are repeated while changing the magnetic field H. That is, if the magnetic field H measured in steps S03 to S05 is an end magnetic field, the measurement procedure proceeds to step S07. If not, the magnetic field H is set to a different desired value in step S02. The spectrum data is acquired again in steps S03 to S05 (step S06). For example, for the magnetic field H of 1 kOe, 2 kOe, 3 kOe, 4 kOe, and 5 kOe, the spectrum data is acquired in steps S03 to S05.

After the spectrum data is acquired for each desired magnetic field H, the Faraday rotation angle θ _F is calculated from the acquired spectrum data (step S07). The Faraday rotation angle θ _F is calculated for each magnetic field H and each wavelength λ.

Specifically, first, the spectral data is corrected by subtracting the background data I ^BG _θ (λ) obtained in step S01 from the spectral data I _{H, θ} (λ) obtained in steps S02 to S06. . When spectrum data after correction for a certain magnetic field H and a certain analyzer angle θ is I ^ _{H, θ} (λ),
I ^ _{H, θ} (λ) = I _{H, θ} (λ) −I ^BG _θ (λ) (2)
It is.

Further, the corrected spectrum data I ^ _{H, θ} (λ) is converted into angle-light intensity data indicating the relationship between the analyzer angle θ and the light intensity I for each magnetic field and each wavelength. For example, in FIG. 5, the relationship between the light intensity I for the wavelength λ ₁ and the analyzer angle θ is obtained by extracting the light intensity I for each analyzer angle θ on a straight line, for example, λ = λ _1. be able to. Hereinafter, the angle-light intensity data for a certain magnetic field H and a certain wavelength λ is described as I _{H, λ} (θ). 6A, 6B, and 6C show the angle-light intensity data I _{H and λ} (θ) obtained for the wavelengths λ ₁ , λ ₂ , and λ ₃ for the specific magnetic field H, respectively. ing.

Further, the Faraday rotation angle θ _F , that is, the rotation angle of the polarization plane in the sample S is calculated from the angle-light intensity data I _{H, λ} (θ). The Faraday rotation angle θ _F can be calculated by various methods.

First, the analyzer angle θ _MIN ′ at which the light intensity I is the smallest in the angle-light intensity data I _{H, λ} (θ) obtained for a certain magnetic field H and a certain wavelength λ is used as it is. You may use for calculation of Faraday rotation angle (theta) _F in wavelength (lambda). In this case, the Faraday rotation angle θ _{F at} a certain magnetic field H and a certain wavelength λ is obtained from the analyzer angle θ _MIN ′ where the light intensity I is minimum in the angle-light intensity data I _{H, λ} (θ).
θ _F = θ _MIN '−90 ° (3)
Is calculated as

However, the analyzer angle θ _MIN ′ at which the light intensity I is minimum in the angle-light intensity data I _{H, λ} (θ) is not used as it is for the calculation of the Faraday rotation angle θ _F but is described below. It is preferable to obtain the Faraday rotation angle θ _F by such data fitting. This is because, in the measurement procedure described above, the angle-light intensity data I _{H, λ} (θ) is acquired only at the analyzer angle θ in predetermined angular increments. Actually, the light intensity I may be minimized at the analyzer angle θ where the angle-light intensity data I _{H, λ} (θ) is not acquired. By obtaining the analyzer angle θ _MIN and / or the Faraday rotation angle θ _F that minimizes the light intensity I by data fitting, the angle θ _MIN and / or the Faraday rotation angle θ _F can be obtained more accurately.

FIG. 7A is a graph showing a first data fitting method for calculating the Faraday rotation angle θ _F for a certain magnetic field H and wavelength λ. First, from the angle-light intensity data I _{H, λ} (θ) acquired for a certain magnetic field H and wavelength λ, light intensity data in a specific range including the analyzer angle θ _MIN ′ where the light intensity I is minimum. Is extracted. FIG. 7A conceptually shows the contents of the extracted data. In one embodiment, data in which the angle of the analyzer 5 is in the range of θ _MIN '−θ _A to θ _MIN ' + θ _A is extracted from the spectral data acquired for the magnetic field H and the wavelength λ. θ _A is selected to be about 5 to 15 ° as an example. Further, the extracted data is fitted with a quadratic approximate curve (for example, I = αθ ² + βθ + γ (α <0)), and the angle θ corresponding to the position of the apex of the approximate curve corresponds to the magnetic field H and wavelength λ. It is calculated as an analyzer angle θ _MIN that minimizes the light intensity I. Further, the following formula (4):
θ _F = θ _MIN −90 ° (4)
Thus, the Faraday rotation angle θ _F is calculated.

によってフィッティングされる。Ｉ_０は、上記の余弦関数の振幅の２倍であり、φは、上記の余弦関数の位相角である。この位相角φは、光強度Ｉを最小とする検光子角度θの９０°からのずれであるから、該磁場Ｈ、波長λについてのファラデー回転角θ_Ｆは、
θ_Ｆ＝φ ・・・（６）
として算出可能である。 FIG. 7B is a graph showing a second data fitting method for calculating the Faraday rotation angle θ _F for a certain magnetic field H and wavelength λ. Referring to FIG. 7B, in the second calculation method, the entire angle-light intensity data I _{H, λ} (θ) obtained for a certain magnetic field H and wavelength λ is fitted with a cosine function. For example, the following formula (5):

Fitted by. I ₀ is twice the amplitude of the cosine function, and φ is the phase angle of the cosine function. Since the phase angle φ is a deviation from 90 ° of the analyzer angle θ that minimizes the light intensity I, the Faraday rotation angle θ _F for the magnetic field H and wavelength λ is
θ _F = φ (6)
Can be calculated as

Subsequently, the Verde constant is calculated (step S08). When the Verde constant is V and the thickness of the sample S (that is, the distance through which the linearly polarized light propagates in the sample S) is d, the magnetic field H and the Faraday rotation angle θ _F are
θ _F = VHd (7a)
Therefore, as shown in FIG. 8, the Verde constant can be calculated as the slope of a graph with the magnetic field H on the horizontal axis and the Faraday rotation angle θ _F on the vertical axis. Specifically, the slope m is obtained by fitting the relationship between the magnetic field H and the Faraday rotation angle θ _{F at} a certain wavelength λ using the function θ _F = mH. From the obtained slope m, the Verde constant V (λ ) Is the following formula (7)
V (λ) = m / d (7b)
Is calculated as By performing the same calculation for each wavelength λ, the wavelength dependence of the Verde constant can be identified. For example, when the slopes m obtained for the wavelengths λ ₁ , λ ₂ , and λ ₃ are m ₁ , m ₂ , and m ₃ , respectively, the Verde constant V (λ) of the wavelengths λ ₁ , λ ₂ , and λ _{3 1} ), V (λ ₂ ), V (λ ₃ ) are respectively
V (λ ₁ ) = m ₁ / d
V (λ ₂ ) = m ₂ / d
V (λ ₃ ) = m ₂ / d (8)
Can be calculated as

  The advantage of the magneto-optical effect measuring apparatus 10 of the present embodiment is that the time required for measuring the wavelength dependence of the Verde constant can be shortened. In the magneto-optical effect measuring apparatus 10 of the present embodiment, linearly polarized light that is white light is incident on the sample S, and the light intensity of each wavelength component is measured by dispersing the light emitted from the analyzer 5. . For this reason, Verde constants of a plurality of wavelengths can be measured without scanning the wavelengths. Therefore, the time required for wavelength dependence measurement can be shortened.

In the first embodiment, if an area sensor is used as the optical sensor 8, the following two benefits can be obtained. First, by using an area sensor as the optical sensor 8, the dynamic range can be expanded. As shown in FIG. 9, the light spot of each wavelength light entering the optical sensor 8 from the spectroscope 7 entering the optical sensor 8 from the spectroscope 7 is in a direction perpendicular to the direction in which the wavelength changes. Stretched. In FIG. 9, the light spots on the surface of the optical sensor 8 of the light having the wavelengths λ ₁ , λ ₂ , and λ ₃ are indicated by reference numerals 51, 52, and 53, respectively. Therefore, by using an area sensor, it is possible to capture a large amount of light for each wavelength and expand the dynamic range. Secondly, as shown in FIG. 10, even when the light spot of each wavelength of light incident on the optical sensor 8 is not linear due to the aberration of the optical system of the magneto-optical effect measuring apparatus 10, the area sensor By using, the light intensity of each wavelength component can be measured in accordance with the shape of the light spot. For example, by designating the area of the optical sensor 8 that measures the light intensity for each wavelength by software, the light intensity of each wavelength component is accurately measured, and as a result, the accuracy of the measurement of the Faraday rotation angle θ _F is improved. Can do. In FIG. 10, the light spots on the surface of the optical sensor 8 of the light with wavelengths λ ₁ , λ ₂ , and λ ₃ are indicated by reference numerals 51a, 52a, and 53a, respectively.

  In the first embodiment, the light source used for measurement is not limited to the white light source 1. The light source used for the measurement may be a light source that generates multicolor light having wavelength components of a plurality of wavelengths desired to be measured (the white light source 1 is also a kind of such light source).

  Further, it is noted that the background data in step S01 is data that is simply used to improve the measurement accuracy, and it is not essential in the present embodiment to correct the spectrum data using the background data. I want. When external light noise is not a problem (for example, when used in an environment with little external light), it is not necessary to correct spectral data using background data. Further, it is not always necessary to acquire the background data every time the sample S is measured.

Second embodiment:
FIG. 11 is a configuration diagram showing the configuration of the magneto-optical effect measuring apparatus 10 according to the second embodiment of the present invention. Similarly to the first embodiment, the magneto-optical effect measurement apparatus 10 of the second embodiment is configured to measure the Verde constant of the sample S. The white light source 1, the polarizer 2, and the electromagnet 3. And an excitation power source 4, an analyzer 5, a spectrometer 7, an optical sensor 8, and an arithmetic device 9.

It should be noted that, in the second embodiment, unlike the first embodiment, the analyzer 5 is fixed and no drive circuit for driving the rotation mechanism of the analyzer 5 is provided. This is because, in the second embodiment, the time required for the measurement of the Verde constant is further shortened by not performing the scanning of the wavelength λ and the scanning of the analyzer angle θ. In the second embodiment, the wavelength dependency of the Verde constant is obtained while fixing the analyzer angle θ by measuring the Verde constant according to the procedure described below. In the description of the measurement procedure of the second embodiment described below, the angle of the transmission axis of the analyzer 5 (that is, the analyzer angle θ) is defined as 90 °. Furthermore, it is defined that the angle of the polarizer 2 is 90 ° when the angle of the transmission axis of the polarizer 2 and the angle of the transmission axis of the analyzer 5 coincide. Further, the angle of the polarizer 2, that the polarizer angle theta _P. That is, the polarizer angle theta _P is is 0 °, and, if the Faraday effect in the sample S is not expressed, the light intensity detected by the light sensor 8 will be the (in principle) zero.

FIG. 12 is a flowchart showing a procedure for measuring the Verde constant by the magneto-optical effect measuring apparatus 10 according to the second embodiment. The Verde constant measurement procedure in the second embodiment is based on the following principle. When Faraday rotation occurs in the sample S in a state where linearly polarized light of white light is incident on the sample S, the light intensity of the light incident on the optical sensor 8 is the case where there is no Faraday rotation (that is, a magnetic field is applied). Change from the light intensity). Here, in the second embodiment, when the Faraday rotation angle θ _F is very small, the fact that the amount of change in the light intensity I of the light passing through the analyzer 5 can be approximated to be proportional to the Faraday rotation angle θ _F is used. . If the relationship between the Faraday rotation angle θ _F and the amount of change in the light intensity I is measured in advance, conversely, the light intensity I when the Faraday rotation occurs and the light intensity when the Faraday rotation does not occur. The Faraday rotation angle θ _F can be calculated from the difference of I. Therefore, in the present embodiment, rotation angle-light intensity change data indicating the relationship between the Faraday rotation angle θ _F and the change amount of the light intensity I is acquired in advance, and the rotation angle-light intensity change data is used. Faraday rotation angle theta _F is calculated. Here, the state of the optical sensor 8 when the Faraday rotation in the sample S a polarizer angle theta _P in a state of not applying a magnetic field of the sample S by causing only small changes predetermined angle occurs is artificially reproduced, this By measuring the amount of change in the light intensity I of each wavelength component of the light incident on the sensor 8 in the state, rotation angle-light intensity change data is facilitated. The measured change amount of the light intensity I of each wavelength component is used as data indicating the relationship between the Faraday rotation angle θ _F and the change amount of the light intensity I.

In the present embodiment, the wavelength dependency α (λ) of the rate of change of the light intensity I per Faraday rotation angle 1 ° is acquired in advance as the rotation angle-light intensity change data (step S11). The wavelength dependency of the Faraday rotation angle θ _F is calculated from the spectrum data obtained in a state where the Faraday rotation is expressed in the sample S, using the wavelength dependency α (λ) of the change rate. Further, the wavelength dependence of the Verdet constant is calculated from the wavelength dependence of the calculated Faraday rotation angle theta _F. The Verde constant measurement procedure in the second embodiment will be described in detail below.

In the measurement procedure of the second embodiment, first, a prior spectrum measurement is performed (step S11). The prior spectrum measurement is measurement of spectrum data for obtaining the wavelength dependency α (λ) of the rate of change of the light intensity I per Faraday rotation angle of 1 ° in the sample S. Specifically, first, the magnetic field H is set to zero, and a white light source 1 is turned on in a state of setting the polarizer angle theta _P in a specific angle θ _{P_SET.} The specific angle θ _{P_SET} is a predetermined angle _satisfying 0 ° <θ _P <90 ° or 90 ° <θ _P <180 °. Of the linearly polarized light of the white light generated by the white light source 1 and the polarizer 2, the component that has passed through the analyzer 5 is incident on the spectroscope 7 and further reaches the optical sensor 8. At this time, spectral data of the light intensity of the light incident on the optical sensor 8 is measured. Here, the amount of change in the optical intensity I increases for Faraday rotation angle theta _F when polarizer angle theta is 45 °, the linear relationship between the amount of change in the optical intensity I against Faraday rotation angle theta _{F Therefore} , the specific angle θ _{P_SET} is in the vicinity of 45 °, more specifically in the range of 43 ° to 47 ° (that is, when the polarization plane of the sample S is not rotated). The angle between the polarization plane of linearly polarized light incident on the photon 5 and the transmission axis of the analyzer 5 is preferably in the range of 43 ° to 47 °, and most preferably 45 °. In the present embodiment, description will be made _assuming that the specific angle θ _{P_SET} at which the polarizer angle θ is set is 45 °. The spectrum data obtained here is described as I _SET (λ).

Subsequently, the white light source 1 is turned on in a state where the polarizer angle θ _P is _rotated from the specific angle θ _{P_SET} by the reference angle θ _REF , and the light intensity spectrum of the light incident on the optical sensor 8 at this time is measured. . Also at this time, the magnetic field H is set to zero. The reference angle θ _REF is, for example, 1 °. As a result, spectrum data in the case where Faraday rotation has occurred in the sample S by the reference angle θ _REF can be obtained in a simulated manner. The spectrum data obtained here is described as I _REF (λ).

As shown in FIG. 13, when the polarizer angle θ _P is _changed from the specific angle θ _{P_SET} by the reference angle θ _REF , the light intensity changes by ΔI. As a result, as shown in FIG. 14, the light intensity spectrum I _REF when the polarizer angle θ is changed by the specific angle θ _{P_SET} and the reference angle θ _{REF is} changed by the light intensity spectrum I _SET (λ). At (λ), a change of ΔI (λ) appears.

The wavelength dependence α (λ) of the rate of change of the light intensity I per Faraday rotation angle of 1 ° is
α (λ) = ΔI (λ) / θ _REF (9)
Is calculated as FIG. 15 is a graph conceptually showing the calculated wavelength dependency α (λ). Data on the wavelength dependence α (λ) of the rate of change of the light intensity I per Faraday rotation angle of 1 ° is stored in the arithmetic unit 9.

  Subsequently, measurement is performed while causing the Faraday effect in the sample S. Specifically, first, the magnetic field H applied to the sample S is set to a desired value (step S12). The magnetic field H is controlled by controlling the excitation current supplied from the excitation power supply 4 to the electromagnet 3.

Further, spectrum data is acquired with the polarizer angle θ returned to the specific angle θ _{P_SET} (= 45 °) (step S13). Specifically, the white light source 1 is turned on while the polarizer angle θ is returned to the specific angle θ _{P_SET} (= 45 °), and linearly polarized light that is white light is incident on the sample S from the polarizer 2. As a result, the light that has passed through the analyzer 5 out of the linearly polarized light that has passed through the sample S enters the spectroscope 7, and each wavelength component that has entered the spectroscope 7 is a photosensor at a position corresponding to the wavelength of the light. 8 is incident. Furthermore, the optical sensor 8 measures the light intensity of each wavelength component of the incident light. Thereby, for the magnetic field H set in step S12, spectral data indicating the relationship between the wavelength λ of light incident on the optical sensor 8 and the light intensity I is acquired. Hereinafter, spectral data obtained for a certain magnetic field H may be referred to as I _H (λ).

  Steps S12 to S13 described above are repeatedly performed while changing the magnetic field H. That is, if the magnetic field H measured in step S13 is the end magnetic field, the measurement procedure proceeds to step S15. If not, the magnetic field H is set to a different desired value in step S12, and then step S13. The spectrum data is acquired again by (Step S14). For example, for the magnetic field H of 1 kOe, 2 kOe, 3 kOe, 4 kOe, and 5 kOe, the spectrum data is acquired in step S13.

After the spectrum data I _H (λ) is acquired for each desired magnetic field H, the Faraday rotation angle θ _F is calculated from the acquired spectrum data I _H (λ) (step S15). The Faraday rotation angle θ _F is calculated for each magnetic field H and each wavelength λ. As described below, for calculating the Faraday rotation angle θ _F , the wavelength dependence α (λ) of the rate of change of the light intensity I per Faraday rotation angle 1 ° obtained in step S11 and the polarizer angle θ Is set to a specific angle θ _{P_SET} (= 45 °), and spectral data I _SET (λ) obtained in a state where the magnetic field H is zero is used.

FIG. 16A conceptually shows the spectrum data I _H (λ) obtained in steps S12 to S14.

First, difference spectrum data _{ΔIP_SET} (λ) is calculated by subtracting the spectrum data I _SET (λ) obtained in step S11 from the spectrum data I _H (λ) obtained in steps S12 to S14. Here, the spectrum data I _SET (λ) obtained in step S11 is obtained in a state where the polarizer angle θ is set to the specific angle θ _{P_SET} (= 45 °) and the magnetic field H is zero. Please note that. FIG. _16B conceptually shows the difference spectrum data _{ΔIP_SET} (λ).

The wavelength dependency θ _F (λ) of the Faraday rotation angle θ _{F is} the wavelength dependency α of the change rate of the light intensity I per Faraday rotation angle 1 ° obtained in step S11 from the difference spectrum data ΔI _{P_SET} (λ). Obtained by dividing by (λ). That is, the wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F is obtained by the following equation (10):
θ _F (λ) = ΔI _{P_SET} (λ) / α (λ) (10)
FIG. 16C conceptually shows the wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F.

Subsequently, the wavelength dependency V (λ) of the Verde constant is calculated from the wavelength dependency θ _F (λ) of the Faraday rotation angle θ _F (step S16). Similar to the first embodiment, the slope m (λ) is obtained by fitting the relationship between the magnetic field H and the Faraday rotation angle θ _F (λ) at each wavelength λ with the function θ _F (λ) = m (λ) H. From the obtained slope m (λ), the Verde constant V (λ) at the wavelength is expressed by the following equation (11).
V (λ) = m (λ) / d (11)
Is calculated as Here, d is the thickness of the sample S.

  Also in the magneto-optical effect measuring apparatus 10 of the second embodiment, Verde constants of a plurality of wavelengths can be measured without performing scanning with respect to wavelengths as in the first embodiment. In addition, in the second embodiment, Verde constants of a plurality of wavelengths can be measured without performing scanning while the analyzer angle θ is fixed. Therefore, it is possible to further reduce the time required for measuring the wavelength dependence.

In the prior spectrum measurement of the second embodiment described above (step S11), the spectrum data I _SET (λ) obtained with the polarizer angle θ set to the specific angle θ _{P_SET} and the polarizer angle θ are calculated. Data of the wavelength dependence α (λ) of the rate of change of the light intensity I per Faraday rotation angle of 1 ° is calculated from the spectrum data I _REF (λ) obtained in the state set to θ _{P_SET} + θ _REF . The polarizer angle θ _P for obtaining spectral data used for calculating the data of the wavelength dependency α (λ) of the rate of change of the light intensity I is not limited to θ _{P_SET} and θ _{P_SET} + θ _REF . The wavelength dependence α (λ) of the rate of change of the light intensity I is a spectrum obtained in a state where the magnetic field H is zero for at least two polarizer angles θ _{P in} the vicinity of the specific angle θ _{P_SET} set in step S13. It can be calculated using the data.

For example, referring to FIG. 17 to FIG. 19, the data of the wavelength dependence α (λ) of the rate of change of the light intensity I per Faraday rotation angle of 1 ° is a state where the polarizer angle θ is set to θ _{P_SET} + θ _REF in the obtained spectrum data _{I REF + (λ),} a polarizer angle theta of θ _{P_SET} -θ _REF spectral data obtained in the set state _{I REF- (λ),} it may be calculated by the following equation:
α (λ) = ΔI ′ (λ) / 2θ _REF
= {I _{REF +} (λ) −I _REF− (λ)} / 2θ _REF (12)
The calculation of the wavelength dependence α (λ) of the rate of change of the light intensity I using the equation (12) means that the difference ΔI of the spectral data is maintained while maintaining the linearity (unless the reference angle θ _REF is excessively increased). Since '(λ) can be increased, there is an advantage that the wavelength dependency α (λ) can be calculated more accurately.

Further, the wavelength dependence α (λ) of the rate of change of the light intensity I is acquired in a state where the magnetic field H is zero for three or more polarizer angles θ _{P in} the vicinity of the specific angle θ _{P_SET} set in step S13. It is also possible to calculate using the obtained spectrum data.

FIG. 20 is a flowchart illustrating a modified example of the Verde constant measurement procedure according to the second embodiment. Measurement procedure of the Verdet constant of Figure 20 is intended to take full region in which the amount of change in the light intensity I can be approximated to be proportional to the Faraday rotation angle theta _F. Polarizer angle theta _P is set to 45 °, if the analyzer angle theta is set to 90 °, the angle of the linearly polarized light incident on the analyzer 5 is 45 ° - [delta least 45 ° + [delta] following ranges ( if δ is appropriately configured minute angle), so that the variation of the light intensity I is proportional to the Faraday rotation angle theta _F. Since the SN ratio can be improved when the absolute value of the change amount of the light intensity I is large, the angle of the linearly polarized light incident on the analyzer 5 covers as wide a range as possible from 45 ° -δ to 45 ° + δ. measured by changing the Faraday rotation angle theta _F is preferably performed. However, the Verde constant measurement procedure illustrated in FIG. 12 uses only the range of 45 ° to 45 ° + δ. In the following, a procedure for measuring the Verde constant for effectively using a region that can be approximated when the amount of change in the light intensity I is proportional to the Faraday rotation angle θ _F is presented.

First, prior spectrum measurement is performed, and the wavelength dependency α (λ) of the rate of change of the light intensity I per Faraday rotation angle of 1 ° is acquired (step S21). The wavelength dependence α (λ) of the rate of change of the light intensity I is determined by the spectral data I _SET (λ) obtained in a state where the polarizer angle θ is set to the specific angle θ _{P_SET} , and the polarizer angle θ is θ _{P_SET} + θ. _It may be calculated from the spectral data I _REF (λ) obtained in the state set to _REF using the equation (9). Instead, the wavelength dependence α (λ) of the rate of change of the light intensity I is determined by _comparing the spectral data I _{REF +} (λ) obtained with the polarizer angle θ set to θ _{P_SET} + θ _REF and the polarizer angle θ. _May be calculated using Equation (12) from spectrum data I _REF− (λ) obtained in a state where is set to θ _{P_SET} −θ _REF . However, for the reasons described later, in the Verde constant measurement procedure of FIG. 20, it is preferable to calculate the wavelength dependency α (λ) of the rate of change of the light intensity I using the equation (12).

Subsequently, measurement is performed while causing the Faraday effect in the sample S. Here, in the measurement procedure of FIG. 20, for each magnetic field H, spectrum data is acquired twice while reversing the direction of the magnetic field H (steps S22 to S25). Specifically, first, the magnetic field H is applied in the same direction as the propagation direction of the linearly polarized light in the sample S (hereinafter referred to as “+ direction”) (step S22). Furthermore, spectrum data is acquired in a state where the polarizer angle θ is set to the specific angle θ _{P_SET} (= 45 °) (step S22). Specifically, the white light source 1 is turned on with the polarizer angle θ set to the specific angle θ _{P_SET} (= 45 °), and linearly polarized light that is white light is incident on the sample S from the polarizer 2. As a result, the light that has passed through the analyzer 5 out of the linearly polarized light that has passed through the sample S enters the spectroscope 7, and each wavelength component that has entered the spectroscope 7 is a photosensor at a position corresponding to the wavelength of the light. 8 is incident. Furthermore, the optical sensor 8 measures the light intensity of each wavelength component of the incident light. Thereby, for the magnetic field H set in step S22, spectral data indicating the relationship between the wavelength λ of the light incident on the optical sensor 8 and the light intensity I is acquired. Hereinafter, the spectral data obtained for the magnetic field H in the + direction in step S22 may be referred to as I _{H +} (λ).

  Subsequently, the direction of the magnetic field H applied to the sample S is reversed in the direction opposite to the propagation direction of the linearly polarized light in the sample (hereinafter referred to as “− direction”) (step S24). The reversal of the direction of the magnetic field H can be easily realized by reversing the direction of the excitation current supplied to the electromagnet 3.

Furthermore, spectrum data is acquired in a state where the polarizer angle θ is set to the specific angle θ _{P_SET} (= 45 °) (step S25). Hereinafter, the spectrum data obtained for the negative direction magnetic field H in step S25 may be referred to as I _H− (λ).

In addition, after the magnetic field H is applied in the − direction and the spectrum data I _H− (λ) is acquired, the magnetic field H may be applied in the + direction and the spectrum data I _{H +} (λ) may be acquired.

  The above steps S22 to S25 are repeatedly performed while changing the magnetic field H. That is, if the magnetic field H measured in steps S22 to S25 is an end magnetic field, the measurement procedure proceeds to step S07. If not, the magnetic field H is set to a different desired value, and then steps S22 to S22 are performed. The spectrum data is acquired again in S25 (step S26). For example, for the magnetic field H of 1 kOe, 2 kOe, 3 kOe, 4 kOe, and 5 kOe, the spectrum data is acquired in steps S22 to S25.

After the spectrum data is acquired for each desired magnetic field H, difference spectrum data ΔI _H (λ) is calculated as the difference between the spectrum data I _{H +} (λ) and the spectrum data I _H− (λ) (step S27). That is, the difference spectrum data ΔI _H (λ) is expressed by the following formula (13).
ΔI _H (λ) = I _{H +} (λ) −I _H− (λ) (13)
Here, when the magnetic field H is inverted, in principle, the direction of the Faraday rotation is reversed, and the magnitude of the Faraday rotation angle θ _F itself does not change. Therefore, the difference spectrum data ΔI _H (λ) is Note that it represents the change in light intensity I for twice the Faraday rotation angle θ _F (2θ _F ).

Subsequently, for each magnetic field H, the wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F is calculated from the difference spectrum data ΔI _H (λ) (step S28). The wavelength dependency θ _F (λ) of the Faraday rotation angle θ _{F is} the wavelength dependency α of the change rate of the light intensity I per Faraday rotation angle 1 ° obtained in step S21 from the difference spectrum data ΔI _H (λ). Divide by (λ) and then divide by 2. That is, the wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F is obtained by the following equation (14):
θ _F (λ) = ΔI _H (λ) / 2α (λ) (14)

Here, in the measurement procedure of FIG. 20, the spectrum data I _SET (λ) obtained in a state where the polarizer angle θ is set to the specific angle θ _{P_SET} is not used for calculation of the difference spectrum data ΔI _H (λ). Please keep in mind. This is because the spectral data I _SET (λ) obtained in a state where the polarizer angle θ is set to the specific angle θ _{P_SET} is not used in the calculation of the wavelength dependency α (λ) of the change rate of the light intensity I. Means that it is advantageous. Therefore, when the measurement procedure of FIG. 20 is adopted, the spectral data I obtained with the wavelength dependence α (λ) of the rate of change of the light intensity I and the polarizer angle θ set to θ _{P_SET} + θ _REF It is preferable to calculate from _{REF +} (λ) and spectrum data I _REF− (λ) obtained in a state where the polarizer angle θ is set to θ _{P_SET} −θ _REF using the equation (12).

Subsequently, the wavelength dependency V (λ) of the Verde constant is calculated from the wavelength dependency θ _F (λ) of the Faraday rotation angle θ _F by the same method as in step S16 of FIG. 12 (step S29). The Verde constant V (λ) at each wavelength is the equation (11) presented above:
V (λ) = m (λ) / d (11)
Is calculated as Here, m (λ) is an inclination obtained by fitting the relationship between the magnetic field H and the Faraday rotation angle θ _F (λ) at each wavelength λ using the function θ _F (λ) = m (λ) H.

According to the Verde constant measurement procedure of FIG. 20, the region that can be approximated when the change amount of the light intensity I is proportional to the Faraday rotation angle θ _F is used to the maximum, and the Verde constant V (λ) is improved while improving the SN ratio. Wavelength dependence can be measured.

Third embodiment:
FIG. 21 is a configuration diagram showing the configuration of the magneto-optical effect measuring apparatus 10 according to the third embodiment of the present invention. Similarly to the second embodiment, the magneto-optical effect measuring apparatus 10 of the third embodiment has a configuration capable of measuring the Verde constant of the sample S while fixing the angle of the analyzer 5 (analyzer angle θ). doing. However, in the magneto-optical effect measuring apparatus 10 of the third embodiment, a Faraday cell 11 is inserted between the white light source 1 and the sample S in addition to the polarizer 2. Relatedly, a drive circuit 12 for supplying a drive current for driving the Faraday cell 11 is provided, and a delay circuit 13 and a function generator 14 for controlling the drive circuit 12 are provided. The delay circuit 13 is also used to generate a shutter signal that controls the timing at which the optical sensor 8 measures the light intensity I of each wavelength component of the light incident thereon. Hereinafter, the magneto-optical effect measuring apparatus 10 of the third embodiment will be described in detail.

  The Faraday cell 11 receives linearly polarized light, which is white light, from the polarizer 2. The linearly polarized light is incident on the sample S after rotating the polarization plane by a rotation angle Δθ proportional to the drive current. Here, as will be described later, since a sinusoidal drive current is supplied from the drive circuit 12 to the Faraday cell 11, a sinusoidal magnetic field is applied to the Faraday cell 11, and the rotation angle Δθ also changes in a sinusoidal manner. Will do. In FIG. 21, the positions of the polarizer 2 and the Faraday cell 11 may be interchanged.

  The drive circuit 12 outputs a drive current having a current level proportional to the signal level of the waveform signal supplied from the function generator 14 to the Faraday cell 11.

  The delay circuit 13 functions as a control unit that controls the operation timing of the function generator 14 so that the operation timing of the optical sensor 8 is synchronized with the drive current supplied to the Faraday cell 11. The delay circuit 13 supplies a synchronization signal to the function generator 14, and thereby controls the phase of the waveform signal that the function generator 14 supplies to the drive circuit 12. In addition, the delay circuit 13 supplies a shutter signal to the optical sensor 8 and controls the timing of measuring the light intensity I of each wavelength component of the light incident on the optical sensor 8. The shutter signal includes a trigger pulse, and when the trigger pulse is input, the optical sensor 8 measures the light intensity I of each wavelength component of the incident light. The delay circuit 13 has a function of controlling the delay of the trigger pulse included in the shutter signal. The operation timing of the delay circuit 13 is controlled by the arithmetic unit 9.

  The function generator 14 supplies a waveform signal to the drive circuit 12 in response to the synchronization signal supplied from the delay circuit 13. The waveform signal supplied from the function generator 14 to the drive circuit 12 is a sine wave. Therefore, the drive current supplied from the drive circuit 12 to the Faraday cell 11 is also a sine wave. The phase of the drive current supplied to the Faraday cell 11 is controlled in synchronization with the synchronization signal supplied from the delay circuit 13.

  FIG. 22 is a conceptual diagram illustrating the principle of Verde constant measurement by the magneto-optical effect measurement apparatus 10 according to the third embodiment. In the description of the measurement procedure of the third embodiment described below, the angle of the transmission axis of the analyzer 5 (that is, the analyzer angle θ) is defined as 90 °.

In this embodiment, when measuring the Verde constant, the angle of the transmission axis of the polarizer 2 (polarizer angle θ _P ) is adjusted to be perpendicular to the angle of the transmission axis of the analyzer 5. That is, the polarizer angle theta _P is adjusted such that 0 °. In a state in which no Faraday rotation occurs in the sample S and no driving current is supplied to the Faraday cell 11, the light intensity detected by the optical sensor 8 is (in principle) zero for all wavelengths λ. become.

First, let us consider a state in which no Faraday rotation occurs in the sample S (that is, a state in which the magnetic field H is not applied to the sample S). In this state, when a Faraday cell 11 is supplied with a sinusoidal drive current having a frequency f, linearly polarized light whose angle of polarization changes in a sinusoidal manner around the angle 0 ° is incident on the analyzer 5. since that, as a result, the optical sensor 8, the light intensity I of each wavelength component amplitude I _0/2, is observed as a sine wave of frequency 2f.

Here, when the Faraday rotation is generated by applying the magnetic field H to the sample S, an offset of the Faraday rotation angle θ _F is generated in the angle of the polarization plane incident on the analyzer 5. As a result, the light intensity I of each wavelength component detected by the optical sensor 8 is modulated. As shown in FIG. 22, the light intensity I detected by the optical sensor 8 has a period T (= 1 / f), while two local maxima appear in one period. Light intensity I _A of one of the two maxima is greater than the light intensity I _B at the other. Hereinafter, referred to as timing in which the light intensity I _A corresponding to a relatively large maximum value appears "Timing A", the timing at which the light intensity I _B appears corresponding to a relatively small maximum value as "timing B". In Figure 22, the light intensity I becomes zero at time t _0, when one cycle of the change in light intensity I starts, timing delayed from time t ₀ by the time t _A is the timing A, the time from the time t ₀ timing delayed by t _B is a timing B. As can be understood from FIG. 22, time t ₀ is a timing at which one cycle of the drive current starts (timing for zero crossing).

Here, as described above, when the Faraday rotation angle θ _F is very small, it can be approximated that the amount of change in the light intensity I of the light passing through the analyzer 5 is proportional to the Faraday rotation angle θ _F. The difference ΔI _A−B between the light intensity I _A and the light intensity I _{B at} timing B is proportional to the Faraday rotation angle θ _F of the sample S. Therefore, if the relationship between the difference ΔI _A-B between the light intensities I _A and I _{B at} the timings A and B and the Faraday rotation angle θ _F is measured in advance, conversely, the timing when the Faraday rotation occurs. a, the light intensity _I a in B, will be able to calculate the Faraday rotation angle theta _F from the difference [Delta] I _a-B and _{I B.} Therefore, in this embodiment, rotation angle-light intensity change data indicating the relationship between the difference ΔI _A-B between the light intensities I _A and I _B at the timings _{A and B} and the Faraday rotation angle θ _F is acquired in advance. The Faraday rotation angle θ _F is calculated using the rotation angle-light intensity change data.

In the present embodiment, simulated the state of the optical sensor 8 when the Faraday rotation occurs in the sample S a polarizer angle theta _P in a state of not applying a magnetic field of the sample S by causing only small changes a predetermined angle timing a on which reproduces the light intensity _I a in B, and the difference [Delta] I _a-B of _{I B} is obtained, the measured difference [Delta] I _a-B, the light intensity _I a at the timing a, B, and _{I B} Is used as rotation angle-light intensity change data indicating the relationship between the difference ΔI _A-B and the Faraday rotation angle θ _F. The Verde constant measurement procedure in the third embodiment will be described in detail below.

FIG. 23 is a flowchart showing a procedure for preparing in advance rotation angle-light intensity change data indicating the relationship between the difference ΔI _A-B between the light intensities I _A and I _B at the timings A and B and the Faraday rotation angle θ _F. It is. In the present embodiment, the wavelength dependence β (λ) of the difference between the light intensities I _A and I _B at the timings A and B per Faraday rotation angle is measured as the rotation angle-light intensity change data.

  Specifically, first, the white light source 1 is turned on with the magnetic field H set to zero (step S31), and a sinusoidal drive current is supplied from the drive circuit 12 to the Faraday cell 11 (step S31). Step S32).

Further, the polarizer angle theta _P is set to a predetermined reference angle theta _REF (step S33). The reference angle θ _REF is, for example, 1 °.

In addition, the delay circuit 13, the delay t _D of the trigger pulse of the shutter signal is set to a time t _A (step S34), thereby, an optical sensor 8, in each period of the drive current, the wavelength at the timing A It is set in a state where the light intensity I _a of the component is measured.

In this state, the light intensity I _A of each wavelength component at the timing A is measured as spectrum data I ⁺ _{A_REF} (λ) by the optical sensor 8 (step S35). Measurement of the light intensity I _A of each of the wavelength components of the timing A is N cycles of the drive current (N is a predetermined natural number) performed N times over, the measured light intensity I average _A spectral data I ⁺ Used as _{A_REF} (λ).

Then, the delay circuit 13, the delay t _D of the trigger pulse of the shutter signal is set to a time t _B (step S35), thereby, an optical sensor 8, in each period of the drive current, the wavelength at the timing B It is set in a state where components of the light intensity I _B is measured.

In this state, the light intensity I _B of each wavelength component at timing B is measured by the optical sensor 8 as spectrum data I ⁺ _{B_REF} (λ) (step S36). Measurement of the light intensity I _B of each of the wavelength components of the timing A is N cycles of the drive current (N is a predetermined natural number) performed N times over, the measured light intensity I mean spectral data I _B ⁺ _Used as _{B_REF} (λ).

Subsequently, the polarizer angle theta _P is made of the measurement as in step S34~S37 even in a state of being set to - [theta] _REF (step S38). Hereinafter, the light intensity I _A of each of the wavelength components of the timing A obtained in a state in which the polarizer angle theta _P is set to - [theta] _REF, spectral data I ^- was described as _{A_REF (λ),} the polarizer angle theta _P is the light intensity _{I B} of each of the wavelength components of the timing B obtained in a state of being set to - [theta] _REF, spectral data ^I _- to as _{B_REF (λ).}

From the spectral data I ⁺ _{A_REF} (λ), I ⁺ _{B_REF} (λ), I ⁻ _{A_REF} (λ), and I ⁻ _{B_REF} (λ), the light intensities I _A and I _{B at} the timings A and B per Faraday rotation angle of 1 °. The wavelength dependence β (λ) of the difference is calculated (step S39). Specifically, β (λ) is calculated by the following equation (15):
_{^{β (λ) = {(I}} + A_REF (λ) -I + B_REF (λ)) + (I - A_REF (λ), I - B_REF (λ))} / 2θ REF ··· (15)
FIG. 24 is a graph conceptually showing the wavelength dependence β (λ) of the difference between the light intensities I _A and I _B at the timings A and B per Faraday rotation angle of 1 °.

In calculating β (λ), only spectral data I ⁺ _{A_REF} (λ) and I ⁺ _{B_REF} (λ) acquired in a state where the polarizer angle θ _P is set to a predetermined reference angle θ _REF is used. May be. In this case, β (λ) is calculated by the following equation (16):
β (λ) = (I ⁺ _{A_REF} (λ) −I ⁺ _{B_REF} (λ) / θ _REF (16)

In FIG. 25, in the third embodiment, the wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F is calculated using the above-described β (λ), and the wavelength dependence V (λ) of the Verde constant is further calculated. It is a flowchart which shows the procedure which calculates | requires.

Specifically, first, the polarizer angle theta _P is white light source 1 is turned on in a state of being set to 0 ° (step S41), further, sinusoidal driving current supplied from the drive circuit 12 to the Faraday cell 11 (Step S42).

Further, the magnetic field H applied to the sample S is set to a desired value (step S43). The magnetic field H is controlled by controlling the excitation current supplied from the excitation power supply 4 to the electromagnet 3. Thereby, Faraday rotation appears in the sample S, and the polarization plane of the linearly polarized light emitted from the sample S is rotated from the polarizer angle θ _P (= 0 °) by the Faraday rotation angle θ _F.

Further, the delay t _D of the trigger pulse of the shutter signal is set to the time t _A (step S44), whereby the photosensor 8 causes the light intensity I _A of each wavelength component at the timing A in each cycle of the drive current. Is set to be measured.

In this state, the light intensity IA of each wavelength component at timing _A is measured by the optical sensor 8 (step S45). Measurement of the light intensity I _A of each of the wavelength components of the timing A is N cycles of the drive current (N is a predetermined natural number) performed N times over, the average of the measured light intensity I _A is, for a magnetic field H Is used as spectral data I _{A, H} (λ).

Subsequently, the delay t _D of the trigger pulse of the shutter signal is set to a time t _B (step S46), thereby, an optical sensor 8, in each period of the drive current of each wavelength component at the timing B light intensity I _B is set to be measured.

In this state, the light intensity IB of each wavelength component at timing _B is measured by the optical sensor 8 (step S47). Measurement of the light intensity I _B of each of the wavelength components of the timing A is N cycles of the drive current (N is a predetermined natural number) performed N times over, the average of the measured light intensity I _B, the magnetic field H Is used as spectral data I _{B, H} (λ). FIG. 26A conceptually shows spectral data I _{A, H} (λ), I _{B, H} (λ) for a specific magnetic field H. FIG.

  The above steps S43 to S47 are repeatedly performed while changing the magnetic field H. That is, if the magnetic field H measured in steps S44 to S47 is an end magnetic field, the measurement procedure proceeds to step S49. If not, the magnetic field H is set to a different desired value in step S43. The spectrum data is acquired again in steps S44 to S47 (step S48). For example, for the magnetic field H of 1 kOe, 2 kOe, 3 kOe, 4 kOe, and 5 kOe, the spectrum data is acquired in steps S44 to S47.

Subsequently, for each magnetic field H, differential spectral data ΔI _{A−B, H} (λ) _, which is the difference between the spectral data I _{A, H} (λ), I _{B, H} (λ) at timings A, B, is calculated. (Step S49). FIG. 26B conceptually shows the difference spectrum data ΔI _{A-B, H} (λ) for a specific magnetic field H.

Further, for each magnetic field H, the wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F is calculated from the difference spectrum data ΔI _{A-B, H} (λ) (step S50). The wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F is obtained by calculating the difference spectrum data ΔI _{A-B, H} (λ) at the timings A and B per 1 Faraday rotation angle obtained by the procedure of FIG. It is obtained by dividing by the wavelength dependency β (λ) of the difference between the light intensities I _A and I _B. That is, the wavelength dependence θ _F (λ) of the Faraday rotation angle θ _F is obtained by the following equation (17):
θ _F (λ) = ΔI _{A−B, H} (λ) / β (λ) (17)

Subsequently, the wavelength dependency V (λ) of the Verde constant is calculated from the wavelength dependency θ _F (λ) of the Faraday rotation angle θ _F by the same method as step S16 of the second embodiment (step S51). . The Verde constant V (λ) at each wavelength is the equation (11) presented above:
V (λ) = m (λ) / d (11)
Is calculated as Here, m (λ) is an inclination obtained by fitting the relationship between the magnetic field H and the Faraday rotation angle θ _F (λ) at each wavelength λ using the function θ _F (λ) = m (λ) H.

  Also in the magneto-optical effect measuring apparatus 10 of the third embodiment, Verde constants of a plurality of wavelengths can be measured without performing scanning with respect to wavelengths, as in the first and second embodiments. Also, the magneto-optical effect measuring apparatus 10 of the third embodiment can measure Verde constants of a plurality of wavelengths without scanning the analyzer angle θ, as in the second embodiment. Therefore, it is possible to further reduce the time required for measuring the wavelength dependence.

In addition, in the magneto-optical effect measuring apparatus 10 of the third embodiment, a region where the light intensity of the light transmitted through the analyzer 5 is smaller than that of the second embodiment is used. That is, since the polarizer angle theta _P is 0 °, the angle of the linearly polarized light incident on the analyzer 5 is an angle close to 0 °. On the other hand, since the analyzer angle θ is 90 °, the light intensity of the light transmitted through the analyzer 5 is small. For this reason, in the magneto-optical effect measuring apparatus 10 of the third embodiment, the resolution of the optical sensor 8 can be effectively used to improve the SN ratio, and the Verde constant can be measured with higher sensitivity. Note that the polarizer angle θ _P may be in the vicinity of 0 °, for example, a range of −2 ° to 2 ° (that is, linearly polarized light incident on the analyzer 5 when the polarization plane of the sample S is not rotated). The angle between the plane of polarization and the transmission axis of the analyzer 5 may be in the range of 88 ° to 92 °.

In the above description of the third embodiment, the driving current supplied to the Faraday cell 11 is described as a sine wave. However, the waveform of the driving current is an alternating current (that is, the driving current). It may be different as long as it is a periodic signal of frequency f (in which the direction is reversed). Even in this case, the light intensity of each wavelength component and the light intensity of the light incident on the optical sensor 8 at the timing (timing A) at which the light intensity of the light incident on the optical sensor 8 takes a relatively large maximum value are relatively From the difference in light intensity of each wavelength component at the timing of taking a small maximum value (timing B), the wavelength dependence β (λ) of the difference between the light intensities I _A and I _B at the timings A and B per Faraday rotation angle of 1 °. Faraday rotation angle theta _F may be calculated using the. In this case, the drive current having the same waveform is also used in calculating the wavelength dependency β (λ) of the difference between the light intensities I _A and I _B.

  FIG. 27 is a configuration diagram illustrating a modified example of the magneto-optical effect measuring apparatus 10 according to the third embodiment. In the configuration of FIG. 27, an image intensifier 15 that performs optical amplification is inserted between the spectroscope 7 and the optical sensor 8. The image intensifier 15 corresponds to a gate operation, and operates in response to a gate signal supplied from the image intensifier driving circuit 16. Here, in the configuration of FIG. 27, the delay circuit 13 supplies the shutter signal including the trigger pulse to the image intensifier driving circuit 16 instead of the optical sensor 8. The image intensifier driving circuit 16 operates the image intensifier 15 when a trigger pulse is input. As described above, in the magneto-optical effect measuring apparatus 10 of the third embodiment, since the light intensity of the light transmitted through the analyzer 5 is small, the image intensifier 15 is used as shown in FIG. It is effective to measure the Verde constant with higher sensitivity.

  In the above embodiment, the configuration of the magneto-optical effect measurement apparatus 10 for measuring the Verde constant representing the magneto-optical activity with respect to the Faraday effect is presented, but the configuration is such that the same measurement is performed on the reflected light of the sample S. Can be changed to measure the Kerr constant representing the magneto-optical activity with respect to the magneto-optical Kerr effect. 28 to 33 show the configuration of the magneto-optical effect measuring apparatus 10 for measuring the Kerr constant.

  FIG. 28 is a configuration diagram showing an example in which the configuration of the magneto-optical effect measuring apparatus 10 of the first embodiment is changed so as to measure the polar Kerr effect. In the magneto-optical effect measuring apparatus 10 in FIG. 28, a half mirror 17 that reflects the reflected light from the sample S is added to the magneto-optical effect measuring apparatus 10 in FIG. 2, and the analyzer 5, spectrometer 7, and optical sensor 8. Is changed so that the light reflected by the half mirror 17 is detected. The incident angle of light incident on the sample S is 0 °. Furthermore, the electromagnet 3 is arranged so as to apply the magnetic field H to the sample S in a direction parallel to the direction of incident light (same direction or opposite direction).

In the magneto-optical effect measuring apparatus 10 of FIG. 28, the Kerr constant of the polar Kerr effect is measured as follows. Linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, enters the sample S via the half mirror 17. The light reflected by the sample S (with the polarization plane rotated by the polar Kerr effect) is reflected by the half mirror 17 and enters the analyzer 5. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, the Kerr rotation angle θ _K at each magnetic field H and each wavelength λ is calculated in the same procedure as calculating the Faraday rotation angle θ _F in the first embodiment from the light intensity of each wavelength component detected by the optical sensor 8. is calculated, the Kerr constant of the polar Kerr effect from the calculated Kerr rotation angle theta _K is obtained.

  FIG. 29 is a configuration diagram showing an example in which the configuration of the magneto-optical effect measuring apparatus 10 of the first embodiment is changed so as to measure the vertical Kerr effect. In the magneto-optical effect measuring apparatus 10 of FIG. 29, the arrangement of the analyzer 5, the spectrometer 7, and the optical sensor 8 is changed so that the light reflected by the sample S can be detected. The incident angle of light incident on the sample S is larger than 0 ° and smaller than 90 °. Further, the electromagnet 3 is arranged so as to apply the magnetic field H in a direction parallel to the surface of the sample S.

In the magneto-optical effect measuring apparatus 10 of FIG. 29, the Kerr constant of the longitudinal Kerr effect is measured as follows. Linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, enters the sample S via the half mirror 17. The light reflected by the sample S (with the polarization plane rotated by the longitudinal Kerr effect) is incident on the analyzer 5. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, the Kerr rotation angle θ _K at each magnetic field H and each wavelength λ is calculated in the same procedure as calculating the Faraday rotation angle θ _F in the first embodiment from the light intensity of each wavelength component detected by the optical sensor 8. is calculated, the Kerr constant of the longitudinal Kerr effect is obtained from the calculated Kerr rotation angle theta _K.

  FIG. 30 is a configuration diagram showing an example in which the configuration of the magneto-optical effect measuring apparatus 10 of the second embodiment is changed so as to measure the polar Kerr effect. In the magneto-optical effect measuring apparatus 10 of FIG. 30, a half mirror 17 that reflects the reflected light from the sample S is added to the magneto-optical effect measuring apparatus 10 of FIG. 11, and the analyzer 5, the spectroscope 7, and the optical sensor 8 are added. Is changed so that the light reflected by the half mirror 17 is detected. The incident angle of light incident on the sample S is 0 °. Furthermore, the electromagnet 3 is arranged so as to apply the magnetic field H to the sample S in a direction parallel to the direction of incident light (same direction or opposite direction).

In the magneto-optical effect measuring apparatus 10 of FIG. 30, the Kerr constant of the polar Kerr effect is measured as follows. Linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, enters the sample S via the half mirror 17. The light reflected by the sample S (with the polarization plane rotated by the polar Kerr effect) is reflected by the half mirror 17 and enters the analyzer 5. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, the Kerr rotation angle θ _K at each magnetic field H and each wavelength λ is calculated in the same procedure as calculating the Faraday rotation angle θ _F in the second embodiment from the light intensity of each wavelength component detected by the optical sensor 8. is calculated, the Kerr constant of the longitudinal Kerr effect is obtained from the calculated Kerr rotation angle theta _K.

  FIG. 31 is a configuration diagram showing an example in which the configuration of the magneto-optical effect measuring apparatus 10 of the second embodiment is changed so as to measure the vertical Kerr effect. In the magneto-optical effect measuring apparatus 10 of FIG. 31, the arrangement of the analyzer 5, the spectroscope 7, and the optical sensor 8 is changed so that the light reflected by the sample S is detected. The incident angle of light incident on the sample S is larger than 0 ° and smaller than 90 °. Further, the electromagnet 3 is arranged so as to apply the magnetic field H in a direction parallel to the surface of the sample S.

In the magneto-optical effect measuring apparatus 10 of FIG. 31, the Kerr constant of the longitudinal Kerr effect is measured as follows. Linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, enters the sample S via the half mirror 17. The light reflected by the sample S (with the polarization plane rotated by the longitudinal Kerr effect) is incident on the analyzer 5. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, the Kerr rotation angle θ _K at each magnetic field H and each wavelength λ is calculated in the same procedure as calculating the Faraday rotation angle θ _F in the second embodiment from the light intensity of each wavelength component detected by the optical sensor 8. is calculated, the Kerr constant of the longitudinal Kerr effect is obtained from the calculated Kerr rotation angle theta _K.

  FIG. 32 is a configuration diagram showing an example in which the configuration of the magneto-optical effect measuring apparatus 10 of the third embodiment is changed so as to measure the polar Kerr effect. In the magneto-optical effect measuring apparatus 10 of FIG. 32, a half mirror 17 that reflects the reflected light from the sample S is added to the magneto-optical effect measuring apparatus 10 of FIG. 27, and the analyzer 5, the spectroscope 7, and the optical sensor 8 are added. Is changed so that the light reflected by the half mirror 17 is detected. The incident angle of light incident on the sample S is 0 °. Furthermore, the electromagnet 3 is arranged so as to apply the magnetic field H to the sample S in a direction parallel to the direction of incident light (same direction or opposite direction).

In the magneto-optical effect measuring apparatus 10 of FIG. 32, the Kerr constant of the polar Kerr effect is measured as follows. Linearly polarized light that is white light generated by the white light source 1 and the polarizer 2 is incident on the sample S via the Faraday cell 11 and the half mirror 17. The light reflected by the sample S (with the polarization plane rotated by the polar Kerr effect) is reflected by the half mirror 17 and enters the analyzer 5. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, a procedure similar to that for calculating the Faraday rotation angle θ _F in the third embodiment from the light intensity of each wavelength component of light at each of timings A and B (see FIG. 22) detected by the optical sensor 8. Thus, the Kerr rotation angle θ _K at each magnetic field H and each wavelength λ is calculated, and the Kerr constant for the polar Kerr effect is obtained from the calculated Kerr rotation angle θ _K.

  FIG. 33 is a configuration diagram illustrating an example in which the configuration of the magneto-optical effect measurement apparatus 10 of the third exemplary embodiment is changed so as to measure the longitudinal Kerr effect. In the magneto-optical effect measuring apparatus 10 of FIG. 33, the arrangement of the analyzer 5, the spectroscope 7, and the optical sensor 8 is changed so that the light reflected by the sample S can be detected. The incident angle of light incident on the sample S is larger than 0 ° and smaller than 90 °. Further, the electromagnet 3 is arranged so as to apply the magnetic field H in a direction parallel to the surface of the sample S.

In the magneto-optical effect measuring apparatus 10 of FIG. 33, the Kerr constant of the longitudinal Kerr effect is measured as follows. Linearly polarized light that is white light generated by the white light source 1 and the polarizer 2 is incident on the sample S via the Faraday cell 11 and the half mirror 17. The light reflected by the sample S (with the polarization plane rotated by the longitudinal Kerr effect) is incident on the analyzer 5. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, a procedure similar to that for calculating the Faraday rotation angle θ _F in the third embodiment from the light intensity of each wavelength component of light at each of timings A and B (see FIG. 22) detected by the optical sensor 8. Thus, the Kerr rotation angle θ _K at each magnetic field H and each wavelength λ is calculated, and the Kerr constant for the longitudinal Kerr effect is obtained from the calculated Kerr rotation angle θ _K.

  In addition, the basic principle of the magneto-optical effect measuring apparatus 10 of the first to third embodiments described above can be applied to a polarization change spectrum measuring apparatus in general that detects a change in the angle of the polarization plane in a substance. That is, in the magneto-optical effect measuring apparatus 10 of the first to third embodiments, if a different mechanism that causes a change in the angle of the polarization plane is used, the wavelength dependence of the change in the angle of the polarization plane due to the mechanism is measured. be able to. For example, the wavelength dependence (polarization change spectrum) of the rotation angle of the polarization plane in the substance can be measured for the substance that rotates the polarization plane according to temperature and / or pressure.

34 to 36 show the configuration of the polarization change spectrum measuring apparatus 20 that detects changes in the angle of the polarization plane with temperature.
Specifically, FIG. 34 shows an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 2) of the first embodiment is changed so as to measure the change in the angle of the polarization plane with temperature. 35 shows an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 11) of the second embodiment is changed so as to measure the change in the angle of the polarization plane with temperature, and FIG. This shows an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 21) of the embodiment is changed so as to measure the change in the angle of the polarization plane with temperature. In the polarization change spectrum measuring apparatus 20 of FIGS. 34 to 36, a thermostatic chamber 21 and a temperature control device 22 for adjusting the temperature inside the thermostatic chamber 21 are provided. The sample S is provided inside the thermostatic chamber 21.

In the polarization change spectrum measuring apparatus 20 of FIG. 34, the temperature dependence of the change in the angle of the polarization plane is measured as follows. Linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, is incident on the sample S in a state where the temperature of the sample S (that is, the temperature inside the thermostatic chamber 21) is set to a desired temperature. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, the rotation angle of the polarization plane at each temperature and each wavelength λ (in the same procedure as calculating the Faraday rotation angle θ _F in the first embodiment from the light intensity of each wavelength component detected by the optical sensor 8 (see FIG. 4). That is, the change in the angle of the polarization plane is calculated.

35, the temperature dependence of the change in the angle of the polarization plane is measured as follows. Linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, is incident on the sample S in a state where the temperature of the sample S (that is, the temperature inside the thermostatic chamber 21) is set to a desired temperature. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, the rotation angle of the polarization plane at each temperature and each wavelength λ (in the same procedure as calculating the Faraday rotation angle θ _F in the second embodiment from the light intensity of each wavelength component detected by the optical sensor 8). That is, the change in the angle of the polarization plane is calculated.

Furthermore, in the polarization change spectrum measuring apparatus 20 of FIG. 36, the temperature dependence of the change in the angle of the polarization plane is measured as follows. In the state where the temperature of the sample S (that is, the temperature inside the thermostatic chamber 21) is set to a desired temperature, the linearly polarized light that is white light generated by the white light source 1 and the polarizer 2 passes through the Faraday cell 11. Incident on the sample S. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, a procedure similar to that for calculating the Faraday rotation angle θ _F in the third embodiment from the light intensity of each wavelength component of light at each of timings A and B (see FIG. 22) detected by the optical sensor 8. Thus, the rotation angle of the polarization plane at each temperature and each wavelength λ (that is, the change in the angle of the polarization plane) is calculated.

FIGS. 37 to 39 each show a configuration of the polarization change spectrum measuring apparatus 30 that detects a change in the angle of the polarization plane due to pressure.
Specifically, FIG. 37 shows an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 2) of the first embodiment is changed so as to measure the change in the angle of the polarization plane due to pressure. 38 shows an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 11) of the second embodiment is changed so as to measure the change in the angle of the polarization plane due to pressure, and FIG. An example is shown in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 21) of the embodiment is changed so as to measure the change in the angle of the polarization plane due to pressure. In the polarization change spectrum measuring apparatus 20 of FIGS. 37 to 39, a pressure vessel 31 and a pressurizing / decompressing device 32 for adjusting the pressure inside the pressure vessel 31 are provided. The sample S is provided inside the pressure vessel 31.

In the polarization change spectrum measuring apparatus 30 of FIG. 37, the pressure dependence of the change in the angle of the polarization plane is measured as follows. With the pressure applied to the sample S (that is, the pressure inside the pressure vessel 31) set to a desired pressure, linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, is incident on the sample S. Is done. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Furthermore, the rotation angle of the polarization plane at each pressure and each wavelength λ (in the same procedure as calculating the Faraday rotation angle θ _F in the first embodiment from the light intensity of each wavelength component detected by the optical sensor 8 ( That is, the change in the angle of the polarization plane is calculated.

Further, in the polarization change spectrum measuring apparatus 30 of FIG. 38, the pressure dependence of the change in the angle of the polarization plane is measured as follows. With the pressure applied to the sample S (that is, the pressure inside the pressure vessel 31) set to a desired pressure, linearly polarized light, which is white light generated by the white light source 1 and the polarizer 2, is incident on the sample S. Is done. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, the rotation angle of the plane of polarization at each pressure and each wavelength λ (in the same procedure as calculating the Faraday rotation angle θ _F in the second embodiment from the light intensity of each wavelength component detected by the optical sensor 8) That is, the change in the angle of the polarization plane is calculated.

Further, in the polarization change spectrum measuring apparatus 30 of FIG. 39, the pressure dependence of the change in the angle of the polarization plane is measured as follows. With the pressure applied to the sample S (that is, the pressure inside the pressure vessel 31) set to a desired pressure, the linearly polarized light that is white light generated by the white light source 1 and the polarizer 2 is converted into the Faraday cell 11. Through the sample S. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, a procedure similar to that for calculating the Faraday rotation angle θ _F in the third embodiment from the light intensity of each wavelength component of light at each of timings A and B (see FIG. 22) detected by the optical sensor 8. Thus, the rotation angle of the polarization plane at each pressure and each wavelength λ (that is, the change in the angle of the polarization plane) is calculated.

40 to 42 show the configuration of the polarization change spectrum measuring apparatus 40 that detects changes in the angle of the polarization plane caused by voltage or current, respectively.
Specifically, FIG. 40 shows an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 2) of the first embodiment is changed so as to measure the change in the angle of the polarization plane due to voltage or current. 41 shows an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 11) of the second embodiment is changed so as to measure the change in the angle of the polarization plane due to voltage or current. These show an example in which the configuration of the magneto-optical effect measuring apparatus 10 (see FIG. 21) of the third embodiment is changed so as to measure the change in the angle of the polarization plane due to voltage or current. In the polarization change spectrum measuring apparatus 40 of FIGS. 40 to 42, a power supply apparatus 41 for applying a desired voltage or current to the sample S is provided.

In the polarization change spectrum measuring apparatus 40 of FIG. 40, the voltage dependency or current dependency of the change in the angle of the polarization plane is measured as follows. In a state where the voltage or current applied to the sample S is set to a desired value, linearly polarized light that is white light generated by the white light source 1 and the polarizer 2 is incident on the sample S. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, in the same procedure as calculating the Faraday rotation angle θ _F in the first embodiment from the light intensity of each wavelength component detected by the optical sensor 8, the polarization plane at each voltage or current and each wavelength λ. Is calculated (that is, the change in the angle of the polarization plane).

41 measures the voltage dependency or current dependency of the change in the angle of the polarization plane as follows. In a state where the voltage or current applied to the sample S is set to a desired value, linearly polarized light that is white light generated by the white light source 1 and the polarizer 2 is incident on the sample S. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Furthermore, in the same procedure as calculating the Faraday rotation angle θ _F in the second embodiment from the light intensity of each wavelength component detected by the optical sensor 8, the polarization plane at each voltage or current and each wavelength λ. Is calculated (that is, the change in the angle of the polarization plane).

42 measures the voltage dependency or current dependency of the change in the angle of the polarization plane as follows. In a state where the voltage or current applied to the sample S is set to a desired value, linearly polarized light that is white light generated by the white light source 1 and the polarizer 2 is incident on the sample S via the Faraday cell 11. The linearly polarized light is incident on the analyzer 5 after the angle of the polarization plane in the sample S is changed. The light that has passed through the analyzer 5 enters the spectrometer 7, and the light intensity of each wavelength component of the light that has passed through the analyzer 5 is detected by the optical sensor 8. Further, a procedure similar to that for calculating the Faraday rotation angle θ _F in the third embodiment from the light intensity of each wavelength component of light at each of timings A and B (see FIG. 22) detected by the optical sensor 8. Thus, the rotation angle of the polarization plane (that is, the change in the angle of the polarization plane) at each wavelength or λ is calculated.

  Although various embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. The present invention can be implemented with various modifications obvious to those skilled in the art.

DESCRIPTION OF SYMBOLS 10: Magneto-optical effect measuring apparatus 1: White light source 2: Polarizer 3: Electromagnet 4: Excitation power supply 5: Analyzer 6: Drive circuit 7: Spectrometer 8: Optical sensor 9: Arithmetic device 11: Faraday cell 12: Drive circuit 13: Delay circuit 14: Function generator 15: Image intensifier 16: Image intensifier drive circuit 17: Half mirror 20, 30, 40: Polarization change spectrum measuring device 21: Thermostatic chamber 22: Temperature control device 31: Pressure vessel 32: Pressurizing and reducing device 41: Power supply devices 51, 51a, 52, 52a, 53, 53a: Light spot 100: Magneto-optical effect measuring device 101: Wavelength variable light source 101a: White light source 101b: Spectrometer 101c, 101d: Slit 102 : Polarizer 103: Electromagnet 104: Excitation power source 105: Analyzer 106: Drive circuit 10 : Photoelectric converter 108: amplifier 109: arithmetic unit

Claims (20)

A light source that generates polychromatic light having wavelength components of a plurality of wavelengths;
A polarizer that generates linearly polarized light from the polychromatic light and that enters the sample into the sample;
An analyzer on which detection light emitted from the sample is incident;
A spectroscope on which the light passing through the analyzer is incident;
Light detecting means for detecting the light intensity of each of the wavelength components of the plurality of wavelengths obtained by spectroscopy by the spectrometer;
An arithmetic unit that calculates the wavelength dependence of the change in angle of the polarization plane of the linearly polarized light by the sample from the light intensity of each of the wavelength components detected in a state where a magnetic field is applied to the sample. Spectrum measuring device. The polarization change spectrum measuring apparatus according to claim 1,
Furthermore, it comprises a magnetic field applying means for applying a magnetic field to the sample,
The arithmetic unit calculates a wavelength dependence of a change in an angle of a polarization plane of the linearly polarized light by the sample from each light intensity of the wavelength component detected in a state where a magnetic field is applied to the sample. Polarization change spectrum measuring device. The polarization change spectrum measuring apparatus according to claim 1,
The polarization change spectrum measuring apparatus further comprising adjusting means for adjusting the temperature of the sample, the pressure applied to the sample, the voltage applied to the sample, or the voltage applied to the sample. A light source that generates polychromatic light having wavelength components of a plurality of wavelengths;
A polarizer that generates linearly polarized light from the polychromatic light and that enters the sample into the sample;
Magnetic field applying means for applying a magnetic field to the sample;
An analyzer on which detection light emitted from the sample is incident;
A spectroscope on which the light passing through the analyzer is incident;
Light detecting means for detecting the light intensity of each of the wavelength components of the plurality of wavelengths obtained by spectroscopy by the spectrometer;
A magneto-optical effect measurement apparatus comprising: an arithmetic unit that calculates wavelength dependence of the magneto-optical effect of the sample from each light intensity of the wavelength component detected in a state where a magnetic field is applied to the sample. The magneto-optical effect measuring device according to claim 4,
The light intensity of each of the wavelength components is measured while changing the analyzer angle, which is the angle of the transmission axis of the analyzer,
The arithmetic unit generates angle-light intensity data indicating a relationship between the analyzer angle and the light intensity for each of the plurality of wavelengths from the light intensity of each of the wavelength components, and the angle-light intensity. A magneto-optical effect measuring device that calculates a rotation angle of a polarization plane in the sample from data and calculates a wavelength dependency of a magneto-optical effect of the sample from the calculated rotation angle. The magneto-optical effect measuring device according to claim 4,
The light intensity of each of the wavelength components is measured in a state where an analyzer angle that is an angle of a transmission axis of the analyzer is fixed,
Rotation angle-light intensity change data indicating the relationship between the rotation angle of the polarization plane in the sample and the change in the light intensity of each of the wavelength components is stored in the arithmetic device in advance.
The arithmetic unit uses the stored rotation angle-light intensity change data to calculate a rotation angle of a polarization plane in the sample from each light intensity of the wavelength component, and from the calculated rotation angle, calculates the rotation angle of the sample. A magneto-optical effect measuring device that calculates the wavelength dependence of the magneto-optical effect. The magneto-optical effect measuring apparatus according to claim 6,
The rotation angle-light intensity change data is data indicating a change in light intensity of each of the wavelength components per unit angle of the rotation angle of the polarization plane in the sample,
The arithmetic unit calculates a difference between each light intensity of the wavelength component detected in a state where a magnetic field is applied to the sample and each light intensity of the wavelength component detected in a state where no magnetic field is applied to the sample. And a rotation angle of the polarization plane of the sample from the rotation angle-light intensity change data. The magneto-optical effect measuring apparatus according to claim 7,
The detection of the light intensity of each of the wavelength components in a state where a magnetic field is applied to the sample, the angle of the transmission axis of the polarizer and the angle of the transmission axis of the analyzer are the rotation of the polarization plane of the sample. A magneto-optical effect measurement apparatus, which is performed in a state where the angle formed by the plane of polarization of linearly polarized light incident on the analyzer and the transmission axis of the analyzer is in the range of 43 ° to 47 ° when there is not. The magneto-optical effect measuring apparatus according to claim 6,
The rotation angle-light intensity change data is data indicating a change in light intensity of each of the wavelength components per unit angle of the rotation angle of the polarization plane in the sample,
The arithmetic unit is configured to detect the light intensity of each of the wavelength components detected in a state where a first magnetic field is applied to the sample in a first direction and the first direction in the second direction opposite to the first direction to the sample. The rotation angle of the polarization plane in the sample is determined from the difference between the light intensity of each of the wavelength components detected in a state where the second magnetic field having the same magnitude as the magnetic field is not applied and the rotation angle-light intensity change data. Calculate the magneto-optical effect measuring device. The magneto-optical effect measuring device according to claim 4,
Furthermore,
A Faraday cell provided in series with the polarizer between the light source and the sample;
A drive circuit for supplying a drive current which is an AC periodic signal to the Faraday cell;
Timing control means for controlling the operation timing of the drive circuit and the optical sensor so that the timing at which the optical sensor measures the light intensity of each of the wavelength components is synchronized with the drive current supplied to the Faraday cell. A magneto-optical effect measuring apparatus. The magneto-optical effect measuring apparatus according to claim 10,
The rotation angle-light intensity change data includes the light intensity of each of the wavelength components at the first and second timings defined for each period of the drive current per unit angle of the rotation angle of the polarization plane in the sample. Data showing the difference,
In the first timing and the second timing, when the polarization plane rotates in the sample, the light intensity of each of the wavelength components detected by the photosensor takes a maximum value that is different in each period of the driving current. Stipulated in
The arithmetic device includes a difference between each light intensity of the wavelength component at the first timing detected in a state where a magnetic field is applied to the sample and each light intensity of the wavelength component at the second timing; A magneto-optical effect measuring apparatus that calculates a rotation angle of a polarization plane in the sample from the rotation angle-light intensity change data. The magneto-optical effect measuring apparatus according to claim 11,
The detection of the light intensity of each of the wavelength components in a state where a magnetic field is applied to the sample, the angle of the transmission axis of the polarizer and the angle of the transmission axis of the analyzer are the rotation of the polarization plane of the sample. The magneto-optical effect measuring apparatus is performed in a state where the angle formed by the plane of polarization of linearly polarized light incident on the analyzer and the transmission axis of the analyzer is adjusted to be in the range of 43 ° to 47 ° when there is not. The magneto-optical effect measuring device according to claim 4, wherein
The magneto-optical effect measuring device, wherein the light detection means is an area sensor. The magneto-optical effect measuring device according to claim 4, wherein
The analyzer, the spectroscope, and the light detection means are arranged so that light transmitted through the sample enters the analyzer.
The arithmetic device calculates the wavelength dependence of the Verde constant of the sample. The magneto-optical effect measuring device according to claim 4, wherein
The analyzer, the spectroscope, and the light detection means are arranged so that light reflected from the sample enters the analyzer.
The arithmetic device calculates the wavelength dependence of the Kerr constant of the sample. A light source that generates polychromatic light having wavelength components of a plurality of wavelengths, a polarizer that generates linearly polarized light from the polychromatic light, and that enters the sample with the linearly polarized light, and a magnetic field applying unit that applies a magnetic field to the sample; A polarization change spectrum measurement method for calculating a wavelength dependence of a change in an angle of a polarization plane of the linearly polarized light by the sample by a polarization change spectrum measurement apparatus including an analyzer to which detection light emitted from the sample is incident. And
Entering the light passing through the analyzer into a spectrometer;
Detecting the light intensity of each of the wavelength components of the plurality of wavelengths obtained by spectroscopy by the spectrometer;
Calculating the wavelength dependence of the change in angle of the plane of polarization of the linearly polarized light by the sample from the light intensity of each of the wavelength components detected in a state where a magnetic field is applied to the sample. Measuring method. A light source that generates polychromatic light having wavelength components of a plurality of wavelengths, a polarizer that generates linearly polarized light from the polychromatic light, and that enters the sample with the linearly polarized light, and a magnetic field applying unit that applies a magnetic field to the sample; A magneto-optical effect measurement method for calculating the wavelength dependence of the magneto-optical effect of the sample by a magneto-optical effect measurement device comprising an analyzer to which detection light emitted from the sample is incident,
Entering the light passing through the analyzer into a spectrometer;
Detecting the light intensity of each of the wavelength components of the plurality of wavelengths obtained by spectroscopy by the spectrometer;
Calculating the wavelength dependence of the magneto-optic effect of the sample from the light intensity of each of the wavelength components detected in a state where a magnetic field is applied to the sample. The magneto-optical effect measurement method according to claim 17,
The light intensity of each of the wavelength components is measured while changing the analyzer angle, which is the angle of the transmission axis of the analyzer,
In calculating the wavelength dependence of the magneto-optical effect of the sample, the angle-light intensity indicating the relationship between the analyzer angle and the light intensity for each of the plurality of wavelengths from the light intensity of each of the wavelength components. A magneto-optical effect measurement method that generates data, calculates a rotation angle of a polarization plane of the sample from the angle-light intensity data, and calculates a wavelength dependency of the magneto-optical effect of the sample from the calculated rotation angle. The magneto-optical effect measurement method according to claim 17,
The light intensity of each of the wavelength components is measured in a state where an analyzer angle that is an angle of a transmission axis of the analyzer is fixed,
Rotation angle-light intensity change data indicating the relationship between the rotation angle of the polarization plane in the sample and the change in light intensity of each wavelength component is prepared in advance,
In calculating the wavelength dependence of the magneto-optical effect of the sample, the rotation angle of the polarization plane in the sample is calculated from the light intensity of each of the wavelength components using the rotation angle-light intensity change data prepared in advance. And calculating the wavelength dependence of the magneto-optical effect of the sample from the calculated rotation angle. The magneto-optical effect measurement method according to claim 17,
The magneto-optical effect measurement apparatus further includes a Faraday cell provided in series with the polarizer between the light source and the sample, and a drive circuit that supplies a drive current that is an AC periodic signal to the Faraday cell; Timing control means for controlling the operation timing of the drive circuit and the optical sensor so that the timing at which the optical sensor measures the light intensity of each of the wavelength components is synchronized with the drive current supplied to the Faraday cell. Has
The rotation angle-light intensity change data includes the light intensity of each of the wavelength components at the first and second timings defined for each period of the drive current per unit angle of the rotation angle of the polarization plane in the sample. Data showing the difference,
In the first timing and the second timing, when the polarization plane rotates in the sample, the light intensity of each of the wavelength components detected by the photosensor takes a maximum value that is different in each period of the driving current. Stipulated in
In calculating the wavelength dependence of the magneto-optical effect of the sample, the light intensity of each of the wavelength components at the first timing detected in a state where a magnetic field is applied to the sample and the wavelength component at the second timing A method of measuring a magneto-optical effect, wherein a rotation angle of a polarization plane in the sample is calculated from a difference between each of the light intensity and the rotation angle-light intensity change data.

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