• Title/Summary/Keyword: anisotropic reflection

Search Result 48, Processing Time 0.018 seconds

Ellipsometric Expressions for a Sample Coated with Uniaxially Anisotropic Layers (단축 이방성 박막들이 코팅된 시료의 타원식)

  • Kim, Sang Youl
    • Korean Journal of Optics and Photonics
    • /
    • v.26 no.5
    • /
    • pp.275-282
    • /
    • 2015
  • The effective reflection coefficients for light obliquely incident upon a substrate coated with uniaxially anisotropic films and with isotropic films are derived. Multiple reflections inside anisotropic films, as well as those inside isotropic films, are properly treated. These expressions, together with the related ellipsometric expressions, can be used to find the nonuniform distribution of an uniaxially anisotropic film perpendicular to the film's surface, by approximating it as consisting of uniaxially anisotropic uniform layers and applying the conventional modeling technique for spectroscopic ellipsometry.

Ellipsometric Expressions for Two Uniaxially Anisotropic Layers Coated on a Multilayered Substrate (두개의 단축이방성 박막이 있는 다층박막 시료의 타원식)

  • Kim, Sang Youl
    • Korean Journal of Optics and Photonics
    • /
    • v.26 no.2
    • /
    • pp.115-120
    • /
    • 2015
  • Explicit expressions are derived for the effective reflection coefficients of obliquely incident light on a multilayered substrate coated with two uniaxially anisotropic films. Based on these reflection coefficients, ellipsometric constants are obtained as function of the tilt and azimuthal angles of the optical axes of the uniaxial films. Explicit expressions are provided, which can be used to separate the effects of surface anisotropy for anisotropic film from that of its bulk anisotropy, so that these expressions may be utilized in characterizing the surface anisotropy of alignment layers.

Polarized Light Out-coupling in Backlight by Collimating the Beam into Lightguide Plate

  • Hwang, Seong-Mo;Kim, Yeun-Tae;Nam, Seung-Ho;Lee, Sin-Doo
    • Journal of Information Display
    • /
    • v.8 no.1
    • /
    • pp.18-21
    • /
    • 2007
  • We developed a new configuration of polarized light out-coupling lightguide plate (LGP) in the LCD backlight. By collimating the light into the LGP, one linear polarization component experienced total internal reflection at the planar interface of LGP and anisotropic layer, whereas the orthogonal polarization was out-coupled along the normal direction through a birefringent layer and subsequent isotropic microstructures.

Ellipsometric Expressions of Multilayered Substrate Coated with a Uniaxially Anisotropic Alignment Layer (단축이방성 배향막이 코팅되어 있는 다층박막시료의 타원식)

  • Kim, Sang Youl
    • Korean Journal of Optics and Photonics
    • /
    • v.24 no.5
    • /
    • pp.271-278
    • /
    • 2013
  • The effective reflection coefficients of an obliquely incident wave on a multi-layered substrate coated with a uniaxially anisotropic alignment layer are derived. The effective reflection coefficients as well as explicit ellipsometric expressions are provided as a function of film constants of multiple layers together with magnitude of anisotropy, direction of optic axis, and thickness of the alignment layer. It is expected that by adapting these expressions to the conventional modelling technique, the ordinary refractive index, the extra-ordinary refractive index, the azimuth angle and the tilt angle of the optic axis, and the thickness of the aligned surface can be determined simultaneously together with the thickness and volume fraction of each layer beneath the alignment layer.

Photoelectrochemical Hydrogen Production on Textured Silicon Photocathode

  • Oh, Il-Whan
    • Journal of the Korean Electrochemical Society
    • /
    • v.14 no.4
    • /
    • pp.191-195
    • /
    • 2011
  • Wet chemical etching methods were utilized to conduct Si surface texturing, which could enhance photoelectrochemical hydrogen generation rate. Two different etching methods tested, which were anisotropic metal-catalyzed electroless etching and isotropic etching. The Si nano-texture that was fabricated by the anisotropic etching showed ~25% increase in photocurrent for H2 generation. The photocurrent enhancement was attributed to the reduced reflection loss at the nano-textured Si surface, which provided a layer of intermediate density between water and the Si substrate.

Polarization Analysis of Light Passing Through Non-uniform Uniaxial Media (비균일 단축 이방성 매질을 투과하는 빛의 편광상태 변화 표현)

  • Ryu, Jang-Wi;Kim, Sang-Youl;Kim, Yong-Ki
    • Korean Journal of Optics and Photonics
    • /
    • v.21 no.4
    • /
    • pp.161-167
    • /
    • 2010
  • We suggest an effective expression of transmission coefficients between uniaxial anisotropic media. To study the transmission of oblique incident light by stratified anisotropic planar structures, we included an imaginary isotropic layer sandwiched between those anisotropic media, and then considered multiple reflection within the imaginary layer. The adequacy of this expression is confirmed by comparing the polarization analysis of light passing through the anisotropic medium and the multi.layered anisotropic media.

Formation of Neutral Beam by Low Angle Reflection

  • Lee, Do-Haing;Jung, Min-Jae;Bae, Jung-Woon;Kim, Sung-Jin;Lee, Jae-Koo;Yeom, Geun-Young
    • Journal of Korean Vacuum Science & Technology
    • /
    • v.7 no.1
    • /
    • pp.23-26
    • /
    • 2003
  • In this study, a neutral beam was formed using a low angle forward reflection of the ion beam and its degree of neutralization at different reflection angles was investigated. When the ion beam was reflected by a reflector at the angles lower than 15$^{\circ}$, most of the ions reflected were neutralized and the lower reflector angle showed the higher degree of neutralization. Photoresist(PR) and SiO$_2$ etchings were carried out with the neutralized oxygen and fluorine radical fluxes, respectively, and highly anisotropic etch profiles could be obtained suggesting the formation of highly directional neutral flux.

  • PDF

A Study on Interpretation of Seismic Reflection Traveltimes in Anisotropic Layers (이방성 지층에서의 탄성파 반사 주시자료의 해석에 관한 연구)

  • Hwang, Se Ho;Yang, Seung Jin;Jang, Seong Hyung;Kim, Jung Yul
    • Economic and Environmental Geology
    • /
    • v.27 no.2
    • /
    • pp.201-207
    • /
    • 1994
  • This paper presents a technique to determine anisotropic elastic coefficients from traveltimes of seismic reflections or vertical seismic profiling (VSP) in tranversely isotropic layers whose thicknesses are known. The elastic coefficients are calculated from three different velocities (vertical, horizontal and skew velocities) which are determined from skew hyperbolic traveltimes by least-square fitting or semblance analysis. This interpretation technique is tested for synthetic traveltime data obtained for transversely isotropic models. The test shows that the anisotropic elastic constants of the models are determined accurately by this interpretation method.

  • PDF

Using the Monte Carlo method to solve the half-space and slab albedo problems with Inönü and Anlı-Güngör strongly anisotropic scattering functions

  • Bahram R. Maleki
    • Nuclear Engineering and Technology
    • /
    • v.55 no.1
    • /
    • pp.324-329
    • /
    • 2023
  • Different types of deterministic solution methods were used to solve neutron transport equations corresponding to half-space and slab albedo problems. In these types of solution methods, in addition to the error of the numerical solutions, the obtained results contain truncation and discretization errors. In the present work, a non-analog Monte Carlo method is provided to simulate the half-space and slab albedo problems with Inönü and Anlı-Güngör strongly anisotropic scattering functions. For each scattering function, the sampling method of the direction of the scattered neutrons is presented. The effects of different beams with different angular dependencies and the effects of different scattering parameters on the reflection probability are investigated using the developed Monte Carlo method. The validity of the Monte Carlo method is also confirmed through the comparison with the published data.

Reflection and propagation of plane waves at free surfaces of a rotating micropolar fibre-reinforced medium with voids

  • Anya, Augustine Igwebuike;Khan, Aftab
    • Geomechanics and Engineering
    • /
    • v.18 no.6
    • /
    • pp.605-614
    • /
    • 2019
  • The present paper seeks to investigate propagation and reflection of waves at free surfaces of homogeneous, anisotropic and rotating micropolar fibre-reinforced medium with voids. It has been observed that, in particular when P-wave is incident on the free surface, there exist four coupled reflected plane waves traveling in the medium; quasi-longitudinal displacement (qLD) wave, quasi-transverse displacement (qTD) wave, quasi-transverse microrotational wave and a wave due to voids. Normal mode Analysis usually called harmonic solution method is adopted in concomitant with Snell's laws and appropriate boundary conditions in determination of solution to the micropolar fibre reinforced modelled problem. Amplitude ratios which correspond to reflected waves in vertical and horizontal components are presented analytically. Also, the Reflection Coefficients are presented using numerical simulated results in graphical form for a particular chosen material by the help of Mathematica software. We observed that the micropolar fibre-reinforced, voids and rotational parameters have various degrees of effects to the modulation, propagation and reflection of waves in the medium. The study would have impact to micropolar fibre-reinforecd rotational-acoustic machination fields and future works about behavior of seismic waves.