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Magneto-optic response of layered media
Kunt, Ota ; Ostatnický, Tomáš (advisor) ; Antoš, Roman (referee)
Optical response of materials strongly depends on their magnetic properties. This phenomenon is also used in materials in the form of thin layers and multi- layers. Using cited literature we summarize theory needed to calculate magneto- optical response of multilayers. The calculation is based on Maxwell equations and magnetic materials are described with effective permittivity tensor. Jones formalism is used to describe polarised light and Yeh formalism is used to de- scribe multilayer response. A program using presented theory was developed and calculations for concrete structure were made. Multilayer parameters were cho- sen to correspond with those of a sample whose magneto-optical response was measured at the Department of Chemical Physics and Optics, MFF UK. 1
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Optical response of magnetic materials
Wagenknecht, David ; Ostatnický, Tomáš (advisor)
David Wagenknecht: Abstract of a diploma thesis Optical response of magnetic materials, 2014 Magnetooptical properties of anisotropic semiconductors are studied to describe asymmetry of Ga1−xMnxAs, because theoretical calculations predict extraordinary behaviour of reflectivity. Analytical formulae to describe materials with non-diagonal permittivity are derived and they are used for the numerical calculations to describe the optical response of the samples available for the measurement. The transversal Kerr effect is calculated and it exhibits asymmetry in both rotation of the plane of polarization and ellipticity of circularly polarized light due to asymmetry in reflectivity. Moreover, longitudinal and polar magnetization are studied because of the influence on the observability of the phenomena. Results are not only used to discuss conditions, which must be satisfied to prove the asymmetry, but also the actual experimental setup is designed to prepare the measurement. 1
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Dynamics of spin polarization in ferromagnetic semiconductors
Šubrt, Jiří
This work was devoted to the measurement of magnetooptical effects in ferromagnetic semiconductors. We analyzed in detail the measurement technique based on a photoelastic modulator and we constructed an experimental setup that enables to measure the spectra of magnetic circular dichroism (MCD), magnetic circular birefringence (MCB), magnetic linear dichroism (MLD), and magnetic linear birefringence (MLB). This setup was used for the measurement of magnetooptical spectra of several samples of ferromagnetic semiconductors (Ga,Mn)As and (Ga,Mn)(As,P).
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Theory of magneto-optics
Zálešák, Ondřej ; Ostatnický, Tomáš (advisor) ; Janda, Tomáš (referee)
Magnetic properties of matter have an effect on their optical response. These properties depend on the microscopic structure of the matter and we distinguish several basic types of magnetism. In the latest research, scientists focus on tri- angualr antiferromagnets and their use in technology, for example in spintronics. We describe the magnetic material by permittivity tensor. Description of the response of the material is derived from Maxwell equations and the reflected light is described by its polarization and ellipticity. Then we model triangular antiferromagnets Γ5g and Γ4g configuration. 1
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Optical response of magnetic materials
Wagenknecht, David ; Ostatnický, Tomáš (advisor)
David Wagenknecht: Abstract of a diploma thesis Optical response of magnetic materials, 2014 Magnetooptical properties of anisotropic semiconductors are studied to describe asymmetry of Ga1−xMnxAs, because theoretical calculations predict extraordinary behaviour of reflectivity. Analytical formulae to describe materials with non-diagonal permittivity are derived and they are used for the numerical calculations to describe the optical response of the samples available for the measurement. The transversal Kerr effect is calculated and it exhibits asymmetry in both rotation of the plane of polarization and ellipticity of circularly polarized light due to asymmetry in reflectivity. Moreover, longitudinal and polar magnetization are studied because of the influence on the observability of the phenomena. Results are not only used to discuss conditions, which must be satisfied to prove the asymmetry, but also the actual experimental setup is designed to prepare the measurement. 1
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Magneto-optic response of layered media
Kunt, Ota ; Ostatnický, Tomáš (advisor) ; Antoš, Roman (referee)
Optical response of materials strongly depends on their magnetic properties. This phenomenon is also used in materials in the form of thin layers and multi- layers. Using cited literature we summarize theory needed to calculate magneto- optical response of multilayers. The calculation is based on Maxwell equations and magnetic materials are described with effective permittivity tensor. Jones formalism is used to describe polarised light and Yeh formalism is used to de- scribe multilayer response. A program using presented theory was developed and calculations for concrete structure were made. Multilayer parameters were cho- sen to correspond with those of a sample whose magneto-optical response was measured at the Department of Chemical Physics and Optics, MFF UK. 1
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Optical response of magnetic materials
Wagenknecht, David ; Ostatnický, Tomáš (advisor) ; Antoš, Roman (referee)
David Wagenknecht: Abstract of a diploma thesis Optical response of magnetic materials, 2014 Magnetooptical properties of anisotropic semiconductors are studied to describe asymmetry of Ga1−xMnxAs, because theoretical calculations predict extraordinary behaviour of reflectivity. Analytical formulae to describe materials with non-diagonal permittivity are derived and they are used for the numerical calculations to describe the optical response of the samples available for the measurement. The transversal Kerr effect is calculated and it exhibits asymmetry in both rotation of the plane of polarization and ellipticity of circularly polarized light due to asymmetry in reflectivity. Moreover, longitudinal and polar magnetization are studied because of the influence on the observability of the phenomena. Results are not only used to discuss conditions, which must be satisfied to prove the asymmetry, but also the actual experimental setup is designed to prepare the measurement. 1
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Dynamics of spin polarization in ferromagnetic semiconductors
Šubrt, Jiří
This work was devoted to the measurement of magnetooptical effects in ferromagnetic semiconductors. We analyzed in detail the measurement technique based on a photoelastic modulator and we constructed an experimental setup that enables to measure the spectra of magnetic circular dichroism (MCD), magnetic circular birefringence (MCB), magnetic linear dichroism (MLD), and magnetic linear birefringence (MLB). This setup was used for the measurement of magnetooptical spectra of several samples of ferromagnetic semiconductors (Ga,Mn)As and (Ga,Mn)(As,P).
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