• Title/Summary/Keyword: magneto-optical

Search Result 257, Processing Time 0.026 seconds

A Study on Direct Current Measurement Using Magneto-Optical LMF Method (자기장학 누설자속법을 응용한 직류전류계측법에 관한 연구)

  • Lee, Jin-Yi
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.24 no.6
    • /
    • pp.566-572
    • /
    • 2004
  • It is necessary to measure the direct current with a non-contact methodology for the liquid or gas phase, as welt as the conducting metals. This paper described a theoretical consideration and experimental verification for a non-contact quantitative direct current measurement system using the Faraday effect and magnetic flux leakage. The leakage of magnetic flux occurs around a gap when a ferromagnetic core including the discontinuous gap is magnetized. Two large anisotropic domains in a magneto-optical film are occurred by the vertical component of leaked magnetic flux and the domain walls are paralleled to the center of the gap. Here, the symmetrical arrangement of domains are deflected when a vertical magnetic field is applied to the magneto-optical film. The domain wall of the magneto-optical film are relocated when a measuring current passes through the ferromagnetic core. Therefore, a direct current passing through the core can be determined quantitatively by the measurement of moving distance of the domain wall.

Development of Integrated Optical Adjustable Attenuator Using Magneto-Optic Effects (자기광학 효과를 이용한 집적형 가변 광감쇠기의 개발)

  • 김동일;정세모
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.24 no.6
    • /
    • pp.1025-1033
    • /
    • 1987
  • This paper describes the development of a new type of an integrated optical adjustable attenuator using magneto-optic effects in 4-layer slab waveguide. The characteristics of the proposed structure are analyzed and evaluated. Furthermore, the fabrication method and attenuation characteristics have been tested by experimets, therby confirming qualitatively the validity of the design theory.

  • PDF

A Study on the Realization of Magneto-Optic Current Transformer by Optical Fiber (광섬유를 이용한 Magneto-Optic Current Transformer실현에 관한 연구)

  • 이상효;김은수
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.8 no.4
    • /
    • pp.139-144
    • /
    • 1983
  • In this paper, the ploarization and Faraday rotation properties of the single mode optical fiber have been investigated for magnto-optic current transformer application. On the analysis, the optical fiber is modeled as a linear retarder and the intrinsic birefreingence of the optical fiber is approximately found to be 2.57'/m from the measurement, and the bend-induced birefringence is proportional to the inverse square of bending radius. The polarization rotation sensitivity is foung to be F/H=1.4x$10^-5$rad/[A/m] from the analysis of Faraday rotation of single mode optical fiber.

  • PDF

Inter Landau Level Optical Absorption in Graphene Under Ultra-high Magnetic Field

  • Saito, H.;Nakamura, D.;Takeyama, S.;Kim, Yong-Min;An, K.S.
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.02a
    • /
    • pp.360-360
    • /
    • 2012
  • Graphene shows diverse novel physical properties arising from its peculiar electronic states, so called Dirac electrons. Especially, effect of magnetic field is very unique, exhibiting exotic Landau level (LL) splitting. LLs are substantially modified by spins of Dirac electrons and pseudo-spins. The degeneracy of LLs is lifted to show splitting by electron-electron interaction and by the Zeeman effect. We investigated the magneto-optical absorption of graphene subjected to ultra-high magnetic field. Samples were prepared by the CVD method deposited on GaAs and Quart substrate. We have confirmed existence of graphene on each substrate by the micro-Raman spectroscopy. Next, we conducted magneto-absorption measurements in magnetic field up to 120 T by the single-turn coil (STC) method. We could observe absorption peak at 65 T and 100 T, respectively, probably arising from the LL inter-band transitions.

  • PDF