• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.36.2-36.2
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• 2008

• Journal of Magnetics
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• 제11권4호
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• pp.195-207
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• 2006

The recently published and new results on design and fabrication of magnetophotonic crystals of different dimensionality are surveyed. Coupling of polarized light to 3D photonic crystals based on synthetic opals was studied in the case of low dielectric contrast. Transmissivity of opals was demonstrated to strongly depend on the propagation direction of light and its polarization. It was shown that in a vicinity of the frequency of a single Bragg resonance in a 3D photonic crystal the incident linearly polarized light excites inside the crystal the TE- and TM-eigen modes which passing through the crystal is influenced by Brags diffraction of electromagnetic field from different (hkl) sets of crystallographic planes. We also measured the faraday effect of opals immersed in a magneto-optically active liquid. It was shown that the behavior of the faraday rotation spectrum of the system of the opal sample and magneto-optically active liquid directly interrelates with transmittance anisotropy of the opal sample. The photonic band structure, transmittance and Faraday rotation of the light in three-dimensional magnetophotonic crystals of simple cubic and face centered cubic lattices formed from magneto-optically active spheres where studied by the layer Korringa-Kohn-Rostoker method. We found that a photonic band structure is most significantly altered by the magneto-optical activity of spheres for the high-symmetry directions where the degeneracies between TE and TM polarized modes for the corresponding non-magnetic photonic crystals exist. The significant enhancement of the Faraday rotation appears for these directions in the proximity of the band edges, because of the slowing down of the light. New approaches for one-dimensional magnetophotonic crystals fabrication optimized for the magneto-optical Faraday effect enhancement are proposed and realized. One-dimensional magnetophotonic crystals utilizing the second and the third photonic band gaps optimized for the Faraday effect enhancement have been successfully fabricated. Additionally, magnetophotonic crystals consist of a stack of ferrimagnetic Bi-substituted yttrium-iron garnet layers alternated with dielectric silicon oxide layers of the same optical thickness. High refractive index difference provides the strong spatial localization of the electromagnetic field with the wavelength corresponding to the long-wavelength edge of the photonic band gap.

• Journal of Magnetics
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• 제8권1호
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• pp.50-59
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• 2003

Spatial light modulators (SLMs) are centrally important devices in volumetric recording, data Processing, Pattern recognition and other optical systems. Various types of reusable SLMs with two-dimensional pixel arrays have been intensively developed. Of these, magneto-optic spatial light modulators (MOSLMs) have advantages of high switching speed, robustness, nonvolatility, and radioactive resistance. In this article, we review recent development work on MOSLMs, mainly in relation to our own studies.

• E2M - 전기 전자와 첨단 소재
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• 제7권6호
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• pp.511-519
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• 1994

The effect of the deposition conditions, such as the base pressure, working pressure, sputtering power, pre-sputtering, and deposition thickness in facing targets sputtering system(FTS), on the oxidation of the TbFeCo thin films was studied by investigating the magneto-optical properties as well as oxygen analysis by the AES depth profiles. The results showed that the base pressure did not affect the magnetic properties so much, probably due to the short flight distance of the sputtered particles. At the higher sputtering power and lower working pressure with pre-sputtering the oxidation of TbFeCo thin films was decreased. As the film thickness increased the TbFeCo thin films showed the perpendicular anisotropy from in-plane anisotropy overcoming the oxidation effect at the beginning of the sputtering.

• Journal of Mechanical Science and Technology
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• 제18권4호
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• pp.640-648
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• 2004

This paper describes a new magnetization method for non-destructive testing with magneto-optical sensor (denoted as MO sensor) which have the following characteristic : high observation sensitivity, independence of the crack orientation, and precise imaging of a complex crack geometry such as multiple cracks. When a magnetic field is applied normally to the surface of a specimen which is significantly larger than its defects, approximately the same magnetic charge per unit area occurs on the surface of the specimen. If there is a crack in the specimen, magnetic charge per unit area has the same value at the bottom of the crack. The distribution of the vertical component of the magnetic flux density, B$\_$Z/, is almost uniform over the no-crack area (denoted as B$\_$Z,BASE/), while the magnetic flux density is smaller in the surroundings of the crack(denoted as B$\_$Z,CRACK/) If B$\_$Z, BASE/ is a bit larger than the saturated magnetic flux density of the MO sensor (B$\_$s/) , then small magnetic domains occur over the crack area and a large domain over the non-crack area because B$\_$Z,CRACK/ is smaller than B$\_$s/.

• 한국광학회지
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• 제16권1호
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• pp.7-12
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• 2005

우리는 버퍼 가스가 포함된 Rb 원자 증기셀을 이용하여 $^{87}$ Rb원자 D$_1$전이선에서 원자결맞음에 의한 비선형 광자기 신호를 관측했다. 측정된 가장 좁은 비선형 광자기 신호의 선폭은 2$\pi$${\times}$464 Hz이고, 이 때 비선형 광자기 효과에 의한 미분형 신호의 peak-to-peak 변화에 해당하는 자기장의 변화는 약 1 mGauss로 측정되었다. 이러한 결과는 고감도 자기장 측정을 위한 광자계 연구에 응용될 수 있다.

• Journal of Magnetics
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• 제8권4호
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• pp.133-137
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• 2003

The magnetostatic properties of the as-deposited and annealed at T=300 and 400$^{\circ}C$ Ni films were investigated employing both magneto-optical magnetometer and VSM. The Ni films of 50∼200 nm thicknesses were prepared by DC magnetron sputtering technique. The strong influence of annealing temperature on magnetostatic properties of the studied samples was discovered. For the annealed Ni films, the increase of the coercivity H$_c$ (up to 4 times) in comparison with that of as-deposited samples was revealed. The obtained results were explained by using crystallographic structural data of the samples.

• Applied Science and Convergence Technology
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• 제23권1호
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• pp.1-13
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• 2014

Semiconductor quantum structures are often characterized by their energy gaps which are modified by the quantum size effect. Energy levels in semiconductors can be realized by optical transitions within confined structures. Photoluminescence spectroscopy in magnetic fields at low temperatures has proved to be a powerful technique for investigating the electronic states of quantum semiconductor heterostructures and offers a complimentary tool to electrical transport studies. In this review, we examine comprehensive investigations of magneto-excitonic and Landau transitions in a large variety of undoped and doped quantum-well structures. Strong magnetic fields change the diamagnetic energy shift of free excitons from quadratic to linear in B in undoped single quantum well samples. Two-dimensional electron gas induced by modulation doping shows pronounce quantum oscillations in integer quantum Hall regime and discontinuous transition at ${\nu}=1$. Such discontinuous transition can be explained as the formation of spin waves or Skyrmions.

• 한국광학회지
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• 제17권1호
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• pp.1-6
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• 2006

우리는 6.7 kPa의 네온 버퍼가스가 포함된 루비듐 증기셀을 이용하여 $^{87}Rb$원자 $D_1$ 전이선에서 레이저의 세기, 증기 셀의 온도, 전이 선에 따른 비선형 광자기 신호(NMOE)의 특성을 조사하였다. 비선형 광자기 신호는 레이저의 세기와 증기셀의 온도가 증가함에 따라 F=2$\to$F'=2 전이선에서는 광자기 신호의 크기와 선폭이 증가하였지만, F=2$\to$F'=1 전이선에서는 확대 없이 신호의 크기만 증가됨으로써 자장 측정 민감도가 향상되는 것을 확인하였으며, 이러한 효과를 자기부준위 사이에서의 원자결맞음 구도의 차이로 설명하였다. 관측된 최적 조건에서 자기장변화에 대한 민감도는 $70pT/\sqrt{Hz}$ 이하로 계산되었다.

• 한국자기학회지
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• 제25권1호
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• pp.1-3
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• 2015

본 연구에서는 스핀-궤도 돌림힘의 광학적 측정 방법을 개발하였다. 사인파 전류에 의해 발생하는 스핀-궤도 돌림힘은 해당 주파수와 두 배 주파수로 진동하는 자화의 운동을 유발하는데, 이로 인해 변화하는 자화의 수직 성분을 극광자기 효과를 이용해 측정하였다. 스핀-궤도 돌림힘이 추가된 란다우-리프쉬츠-길버트 방정식의 평형 조건으로부터, 스핀-궤도 돌림힘에 의한 유효 자기장을 정량적으로 분석하였다. 이러한 측정법을 Pd/Co/Pt 박막 시료에 적용하여, 스핀-궤도 돌림힘 효율의 종 방향과 횡 방향의 성분 값을 각각 나누어 측정하는데 성공하였다. 본 연구에서 제시한 측정 및 분석 방법은 기존의 전기적 측정에 비해 오류가 적기 때문에, 스핀-궤도 돌림힘을 측정하는 더 개선된 방법으로 사용할 수 있다.