• Journal of Magnetics
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• v.3 no.2
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• pp.49-54
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• 1998

Dependence of magnetic and magneto-optic properties on composition of amorphous NdFe alloys has been studied to identify a promising magneto-optic recording material in the wavelength of a blue laser beam. From the view point of crystallographic state, perpendicular magnetic anisotropy energy and polar Kerr rotation angle, the Nd-rich region was found to be suitable for the research purpose.

• The Korean Journal of Ceramics
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• v.1 no.2
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• pp.91-95
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• 1995

Polycrystalline bismuth- and aluminum- substituted dysporsium and yttrium iron garnet (Bi2R3-xAlyFe5-yO12, R=Dy or Y, $0\leqx\leq3, \; 0\leqy\leq3$) films have been prepared by pyrolysis. The crystallization temperatures, the solubility limit of bismuth ions into the garnet phase, and magnetic and magneto-optic properties of the films have been investigated as a function of bismuth and aluminum concentration. It was found that the crystallization temperatures as a function of bismuth and aluminum concentration. It was found that the crystallization temperatures of these films rapidly decreased as bismuth concentration. It was found that the crystallization temperatures of these films rapidly decreased as bismuth concentration (x) increased up to x=1.5 and then remained temperatures of these films rapidly decreased as bismuth concentration (x) increased up to x=1.5 and then remained unchanged at x>1.5, whereas, showed no changes as aluminum concentration (y) increased up to y=1.0 and then gradually increased at y>1.0. The solubility limit of bismuth ions was x=1.8 when y=0 but increased to x=2.3 when y=1.0. It was demonstrated that the magnetic and magneto-optic properties of the dysprosium iron garnet films could be tailored by bismuth and aluminum substitution suitable for magneto-optic recording as follows. The saturation magnetization and coercivity data obtained for the films indicated that the film composition at which the magnetic compensation temperature became room temperature was y=1.2 when x=1.0. Near this composition the coercivity and the squareness of the magnetic hysteresis loop of the films were several kOe and unit, respectively. The Curie temperatures of the films increased with the increase of x but decreaed with the increase of y, and was 150-$250^{\circ}C$ when x=1.0 and y=0.6-1.4. The Faraday rotation at 633 nm of the films increased as x increased but decreased as y increased, and was 1 deg/$\mu\textrm{m}$ when x=1.0 and y=1.0. Based on the data obtained, the appropriate film composition for magneto-optic recording was estimated as near x=1.0 and y=1.0 or $BiDy_2AlFe_4O_{12}$.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.121-124
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• 1997

Emergence of advanced materials has been realized by the great demands for sophisticated state devices in high technology industry. It is the ear of speedy evolution of science and technology, in particular, materials processing technology, which enables us to synthesize any materials with respect to its purity and its perfection of crystal structure and shape (form) that have, heretofore not been available. The availability of ultra pure, fine raw materials, single crystals and thick/thin film materials has been largely responsible for such startling progresses that have been made in the realization of unforeseen, functional devices for high technology industry. Of the functional devices such as passive as active devices, non-silicon devices are mostly passive. Piezoelectric, electro-optic, magneto-optic devices, etc. are some of the examples. In this paper, magneto-optic materials for Faraday device, which is little known, are reviewed including its processing toward practical applications.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.166-169
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• 2000

This paper briefly reviews magneto-optic spatial light modulators (MOSLMs) developed so far and discusses the design concepts, issues concerning its fabrication, and performances of a new MOSLM based on one-dimensional magnetophotonic crystal (1D-MPC). (omitted)

• Journal of the Korean Magnetics Society
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• v.21 no.4
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• pp.141-146
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• 2011

We will introduce the surface magneto-optic Kerr effect (SMOKE), which is one of the most helpful experimental methods in the area of surface magnetism for the last two decades. The basic magnetic characteristics of magnetic thin film is the most essential part for the further understanding and application. For example, the possibility of the realization of ferromagnetism for a single layer of iron, its Curie temperature far below that of bulk iron, and the direction of easy axis are the fundamental questions for the spintronic application. SMOKE is an efficient method to answer for the questions above.

• Journal of the Korean Magnetics Society
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• v.10 no.2
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• pp.93-98
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• 2000

Drive line shape for reflective magneto-optic spatial light modulator has been designed by computer simulation. A factor of 3 improvement in pixel switching sensitivity and power consumption, compared to the conventional reflective magneto-optic spatial light modulator, has been achieved by the use of wedge-shape drive line and a soft magnetic layer. A factor of 2 higher optical efficiency and a factor of 2 simpler fabrication process have been achieved by the use of drive lines that covers most of the surface of pixel and unpatterned insulator.

• Journal of Magnetics
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• v.2 no.2
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• pp.46-49
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• 1997

This paper reports the first success in enhancement of the magneto-optic figure of merit of garnet films in blue wavelengths. The maximum of the absolute value of the Faraday rotation angle observed at about 500 nm for the films with no La substitution shifted toward shorter wavelength as La content increased, that leads the increase of the absolute value of the Faraday rotation angle in the wavelengths shorter than about 480 nm. The optical absorption coefficient at the wavelengths shorter than 500 nm decreased as La content increased. As a result the magneto-optic figure of merit increased in the wavelengths shorter than 470 nm as La content increased and was about two times larger for the film with La content of 0.6 in formular unit compared to that of the film without La substitution. This might be attributed to the shift of the centers of the charge transfer and crystal field transitions by La substitution.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.6
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• pp.52-57
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• 1983

We report a theoretical study on wave propagation in magneto-optic thin-film waveguides. The field distribution and phase velocity of the guided hybrid modes are analyzed in terms of the phase difference of basic system modes and the Faraday rotation of the magneto-optic thin film. Splitting of the phase constant curves due to the F araday rotation is discussed. The present hybridmode analysis leads to a conversion matrix which shows that the distance dependence of the mode conversion in the guide is different from that in the bulk medium.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.3
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• pp.245-250
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• 2004

This paper proposes a new method of measuring an air interface distance between a solid immersion lens(SIL) applied magneto-optic technology and the disk surface. For applying near-field recording (NFR) technology to the magneto-optic storage devices for the next generation, it is positively necessary to maintain the small air gap under about 100㎚. We design an apparatus that consists of some optical components such as a prism, a polarizer and an analyzer. By using the Fresnel reflection coefficient equation, Jones matrices calculation and Malus's law, we establish a mathematical model for understanding the characteristics of the system. The simulations are based on the mathematical model and through the simulation results which is made with various cases we can estimate the performance of the new optical gap sensor system. Experimental results, which are also based on the mathematical model for specific cases, are in good agreement with simulated ones and demonstrate the possibility as the new optical gap sensor.

• Journal of Magnetics
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• v.11 no.3
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• pp.143-146
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• 2006

We attempted to fabricate a new type of magneto optic spatial light modulator (MO-SLM) for multiple-tone modulation by using in-plane magnetization. In the MO-SLM, magnetic property of magneto-optical layer was modified to be suitable for multiple-tone expression by substituting Al in Bi:YIG film. At a driving current to 28 mA in an electrode of the fabricated MO-SLM, changes in brightness of pixels were observed using a polarization microscope.