• 제목/요약/키워드: magneto-optical

검색결과 257건 처리시간 0.023초

타원형 고체잠입렌즈를 이용한 근접장 광자기 기록 (Magneto-Optical Recording in Near-Field using Elliptic Solid Immersion Lens)

  • 박재혁;이문도;박노철;박영필
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.678-681
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    • 2003
  • In conventional optical data storage numerical aperture (NA) cannot be over 1 because of diffraction limit. To overcome this limitation. solid immersion lens(SIL) have produced a great interest in near-field optical data storage. In conventional optical recording method, the dual lens system using object lens and SIL had been studied generally. But the conventional SIL system has some critical problems that must be solved. The problems are heat, contamination. alignment of optical components and so on. To solve these problems. this work proposes enhanced SIL which has several advantages for mechanical and optical issues. This new SIL system named elliptic SIL(ESIL) can use evanescent energy in near-field more effectively. In addition. because of applying the inside recording unlike previous surface recording, ESIL can clear up the problems. The design and analysis of ESIL art executed by using CODE V. Also, in this paper we composed actual data recording system and achieved recording experiment by applying ESIL to magneto-optical recording. In conclusion. we analyze the improvement of aerial density and the reasonability of application to real data storage system.

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Frontiers in Magneto-optics of Magnetophotonic Crystals

  • Inoue, M.;Fedyanin, A.A.;Baryshev, A.V.;Khanikaev, A.B.;Uchida, H.;Granovsky, A.B.
    • 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.

Optical Measurement of Magnetic Anisotropy Field in Nanostructured ferromagnetic Thin Films

  • Whang, Hyun-Seok;Yun, Sang-Jun;Moon, Joon;Choe, Sug-Bong
    • Journal of Magnetics
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    • 제20권1호
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    • pp.8-10
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    • 2015
  • The magnetic anisotropy field plays an important role in spin-orbit-torque-induced magnetization dynamics with electric current injection. Here, we propose a magnetometric technique to measure the magnetic anisotropy field in nanostructured ferromagnetic thin films. This technique utilizes a magneto-optical Kerr effect microscope equipped with two-axis electromagnets. By measuring the out-of-plane hysteresis loops and then analyzing their saturated magnetization with respect to the in-plane magnetic field, the magnetic anisotropy field is uniquely quantified within the context of the Stoner-Wohlfarth theory. The present technique can be applied to small nanostructures, enabling in-situ determination of the magnetic anisotropy field of nanodevices.

Zeeman 감속기를 사용하여 감속된 원자의 포획과 포획된 원자의 특성 (Magneto-optical trap of slowed sodium atoms by using a Zeeman slower and the characteristics of trapped atoms)

  • 고광훈;정도영;한재민;이종민
    • 한국광학회지
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    • 제12권5호
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    • pp.347-351
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    • 2001
  • Zeeman 감속기를 사용하여 감속한 나트륨 원자를 자기광학적 방법으로 포획하였다. 자기광학적 방법으로 포획된 원자의 개수와 온도를 측정하고, 포획이 가능한 포획광의 주파수 영역과 펌핑광의 주파수영역을 나타내었다. Zeeman 감속기로부터 유입하는 원자의 양을 조절한 경우에 원자 개수의 증가율과 감소율을 측정하고, 이들 차이로부터 $N_2$에 비례하는 손실에 대하여 논의하였다.

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Solid-state Reactions in Ni/Si Multilayered Films, Investigated by Optical and Magneto-optical Spectroscopy

  • Lee, Y. P.;Kim, S. M.;Y. V. Kudryavtsev;Y. N. Makogon
    • 한국진공학회지
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    • 제12권S1호
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    • pp.7-9
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    • 2003
  • Solid-state reactions in Ni/Si multilayered films (MLF) with an overall stoichiometry of $Ni_2Si$, NiSi and $NiSi_2$, induced by ion-beam mixing (IBM) and thermal annealing, were studied by using spectroscopic ellipsometry and magneto-optical spectroscopy as well as x-ray diffraction (XRD). The mixing was performed with Ar+ ions of an energy of 80 keV and a dose of $1.5 x\times10^{16}$ $Ar^+$/$\textrm{cm}^2$. It was shown that the IBM induces structural changes in the Ni/Si MLF, which cannot be detected by XRD but are confidently recognized by the optical method. A thermal annealing at 673 K of the Ni/Si MLF with an overall stoichiometry of NiSi and $NiSi_2$ causes formation of the first η -NiSi phase. The first trace for $NiSi_2$ phase on the background of NiSi one was detected by XRD after an annealing at 1073 K while, according to the optical results, $NiSi_2$ turns out be the dominant phase for the annealed Ni/Si MLF with an overall stoichiometry of $NiSi_2$.