• 한국광학회지
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• 제3권2호
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• pp.105-110
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• 1992

광자기 기록 박막의 자기 광학효과에 의한 미소 편광 회전각을 축정하기 위하여 편광 변조 방법을 이용하였다. 편광 변조 방법은 Faraday 회전자로 레이저광의 편광을 변조하고 phase sensitive detection방법을 써서 변조된 신호만을 선택적으로 검출하는 것이다. 본 실험에서는 진공증착법으로 제작된 TbFeCo박막과 RF 스퍼터링으로 제작된 iron garnet 다결정 박막의 자기 Kerr 회전 및 Faraday 회전 이력곡선을 이 방법으로 조사하였다. 그 결과 $0.25^{\circ}$정도의 미소한 회전각을 측정하였으며 특히 longitudinal Kerr 회전의 경우 $2.5\times10^{-3^\circ}$정도의 매우 작은 회전각도 측정할 수 있었다.

• Current Optics and Photonics
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• 제4권2호
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• pp.134-140
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• 2020

A significant enhancement of the magneto-optical Faraday rotation and extraordinary optical transmission (EOT) in the cascaded double-fishnet (CDF) structure with periodic rectangular apertures is theoretically predicted by using the extended finite difference time domain (FDTD) method. The results demonstrate that the transmittance spectrum of the CDF structure has two EOT resonant peaks in a broad spectrum spanning visible to near-infrared wavebands, one of them coinciding with the enhanced Faraday rotation and large figure of merit (FOM) at the same wavelength. It is most important that the resonant position and intensity of the transmittance, Faraday rotation and FOM can be simply tailored by adjusting the incident wavelength, the thickness of the magnetic layer, and the offset between two metallic rectangular apertures, etc. Furthermore, the intrinsic physical mechanism of the resonance characteristics of the transmittance and Faraday rotation is thoroughly studied by investigating the electromagnetic field distributions at the location of resonance. It is shown that the transmittance resonance is mainly determined by different hybrid modes of surface plasmons (SPs) and plasmonic electromagnetically induced transparency (EIT) behavior, and the enhancement of Faraday rotation is mostly governed by the plasmonic electromagnetically induced absorption (EIA) behavior and the conversion of the transverse magnetic (TM) mode and transverse electric (TE) mode in the magnetic dielectric layer.

• 한국결정성장학회지
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• 제10권4호
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• pp.286-291
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• 2000

수직 Bridgman법으로 $Cd_{1-x}Mn_{x}Te$ 단결정을 성장시켜 자기장과 파장을 변화시키면서 Faraday회전을 측정하였다. Verdet 상수값은 포톤의 에너지가 높은 쪽으로 이동함에 따라 흡수단 근처에서 최대였고, 조성비 x에 따라 증가하다가 x=0.40 이상에서 감소하였다. $Cd_{1-x}Mn_{x}Te$ 단결정을 Faraday 소자로 이용할 경우, 흡수단 근처에서 Faraday 회전이 가장 크게 일어나는 $Cd_{0.60}Mn_{0.38Te}$ 단결정이 적합하고,광원으로 He-Ne레이저를 사용할 경우에는 $Cd_{0.62}Mn_{0.40}Te$ 단결정이 유용함을 알 수 있었다.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1982년도 추계학술발표회논문집
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• pp.67-70
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• 1982

In this paper, the intrinsic birefringence and Faraday rotation of the single mode optical fiber have been investigated. On the analysis, the optical fiber has been modeled as a linear retarder and the intrinsic linear retardation of the fiber is approximatly found to be 2.57 deg/m from the measurement. Faraday ratation was analyzed as perturbation theory and Jones matrix.

• 천문학회지
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• 제37권5호
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• pp.337-342
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• 2004

The presence of magnetic fields in the intracluster medium in clusters of galaxies has been revealed through several different observational techniques. These fields may be dynamically important in clusters as they will provide additional pressure support to the intracluster medium as well as inhibit transport mechanisms such as thermal conduction. Here, we review the current observational state of Faraday rotation measure studies of the cluster fields. The fields are generally found to be a few to 10 $\mu$G in non-cooling core clusters and ordered on scales of 10 - 20 kpc. Studies of sources at large impact parameters show that the magnetic fields extend from cluster cores to radii of at least 500 kpc. In central regions of cooling core systems the field strengths are often somewhat higher (10 - 40 $\mu$G) and appear to be ordered on smaller scales of a few to 10 kpc. We also review some of the recent work on interpreting Faraday rotation measure observations through theory and numerical simulations. These techniques allow us to build up a much more detailed view of the strength and topology of the fields.

• 한국광학회지
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• 제6권4호
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• pp.352-358
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• 1995

$Tb^{3+}$이온이 첨가된 Hoya FR5 유리와 $Ce^{3+}$이론이 첨가된 Hoya FR4 유리의 Faraday 회전과 자기화를 4.2K-10K 저온 영역에서 자기장을 80kG까지 증가시키면서 온도 T와 자기장 H의 함수로 측정하였다. 사용파장은 아르곤 레이저의 514.5nm였다. H/T> $5kG.K^{-1}$ 이상에서 나타난 자기화 및 Faraday 회전의 포화현상을 상자성체 양자이론으로 해석할 수 있었다. 계산된 맺음변수들로부터 $Ce^{3+}$ 유리의 큰 Verdet 상수는 $4f\rightarrow5d$궤도 유효 전기쌍극자 전이효과에 기인되고 $Tb^{3+}$ 유리의 큰 Verdet 상수는 자기화에 기인됨을 알 수 있었다.

• 천문학회보
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• 제42권1호
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• pp.56.1-56.1
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• 2017

When turbulent motions perturb magnetic field lines and produce magnetic fluctuations, the perturbations leave imprints of turbulence statistics on magnetic field. Observation of synchrotron radiation is one of the easiest ways to study turbulent magnetic field. Therefore, we study statistical properties of synchrotron polarization emitted from media with magnetohydrodynamic (MHD) turbulence, using both synthetic and MHD turbulence simulation data. First, we obtain the spatial spectrum and its derivative with respect to wavelength of synchrotron polarization arising from both synchrotron radiation and Faraday rotation. The study of spatial spectrum shows how the spectrum is affected by Faraday rotation and how we can recover the statistics of underlying turbulent magnetic field as well as turbulent density of electrons from interferometric observations that incorporate the effects of noise and finite telescopic beam size. Second, we study quadrupole ratio to quantitatively describe the degree of anisotropy introduced by magnetic field in the presence of MHD turbulence. We consider the case that the synchrotron emission and Faraday rotation are spatially separated, as well as the situation that the sources of the synchrotron radiation and thermal electrons causing Faraday rotation exist in the same region. In this study, we demonstrate that the spectrum and quadrupole ratio of synchrotron polarization can be very informative tools to get detailed information about the statistical properties of MHD turbulence from radio observations of diffuse synchrotron polarization.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.223-224
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• 2009

• 한국자기학회지
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• 제5권5호
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• pp.810-814
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• 1995

LPE growth experiment were carried out to make garnet crystal for Faraday rotator and we have evaluated the characteristics of Faraday rotator by a measurement system which is consist of electromagnet and optical components, also done Laue pattern analysis. The thickness of garnet film was $180\;\mu\textrm{m}$ and the Faraday rotation of this film was 388 deg/Cm at wavelength $1.55\;\mu\textrm{m}$, room temperature.

• 대한전자공학회논문지SD
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• 제41권6호
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• pp.33-41
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• 2004

본 논문에서는, 편광측정법에 의한 광섬유 전류 센서(P-FOCS)를 실험·제작하여, 실제 필드에 적용할 수 있는 P-FOCS의 상용화 가능성에 대하여 연구하였다. P-FOCS는 인가된 전류에 의해 발생한 자기장에 비례하는 Faraday 회전각을 측정함으로서 인가된 전류를 측정한다. P-FOCS의 센싱 광섬유로는 저복굴절 광섬유를 사용하여 밴딩에 의한 선복굴절의 영향을 최소화하였으며, 벌크(bulk)한 광학소자의 사용으로 인한 광 손실을 막기 위해 전 광섬유 소자를 사용하였다. 또한, 구성된 신호처리회로는 광섬유 소자들의 연결부에서의 손실로 인한 출력 신호의 강도 변화를 제거하기 위해 사용된다. Faraday 회전각은, 632.8nm 파장의 광원을 이용하여 권선수가 약 1500인 솔레노이드에 전류를 인가해 7500A의 전류원의 효과를 얻도록 하여, 솔레노이드 내부에 센싱 광섬유를 통과시켜 측정하였다. $1000A{\sim}7500A$ 범위에서, 선형성의 측정 오차는 약 1.5% 이내였다.