• ETRI Journal
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• 제36권6호
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• pp.889-893
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• 2014

This paper presents a high-performance dual-circularly polarized feed employing a dielectric-filled circular waveguide. Novel features are incorporated in the proposed feed, such as a dielectric rod radiator for high gain and good impedance matching; dual quarter-wave chokes for low axial ratio over wide angles and for low back radiation; an integrated septum polarizer; and two end-launch-type coaxial-to-waveguide transitions. The proposed feed shows excellent performance at 5.0 GHz to 5.2 GHz.

• Journal of Information Display
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• 제5권2호
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• pp.27-38
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• 2004

We describe dried oriented films with anisotropic structural and optical properties prepared from the aqueous solutions of plank-like molecules, the so-called Lyotropic Chromonic Liquid Crystals (LCLCs). The dried LCLC films may be used as optical elements, such as polarizers, compensators, color filters, or retardation plates in the UV, visible, or infrared parts of spectrums. The optical quality of the films is determined by the uniformity of the molecular alignment, which often distorted by periodic variations of the director field. We describe different ways to improve the alignment properties of the films by using additives. We present compositions capable of polarizing effects in visible and UV parts of spectrum.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1250-1256
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• 2017

This paper proposes the design of microstrip patch antennas for dual-band polarization adjustment. The antenna has a multi-layer structure for dual-band operation, and each layer contains a resonating patch with surrounding strips separated into two parts. The antenna polarization is adjusted by varying the separated positions of the strips, while fixing other design parameters. To demonstrate the feasibility, an antenna sample with right-hand circular polarization is fabricated, and its antenna characteristics are measured in a full anechoic chamber. The operating principle of polarization adjustment in the dual frequency bands is also verified by observing near electromagnetic fields and the magnetic surface current density around the antenna.

• 한국인쇄학회지
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• 제18권2호
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• pp.113-124
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• 2000

It is well known that the characteristics of liquid crystal polymer composite(LCPC) films are possessed of large-area and flexible display, polarizer free, high contrast, wide angle of visual filed and high responsiveness. In this study, we have investigated to the best optimal mixing rates chiral nematic liquid crystals and UV-curable resins having different properties acrylate moleculars. The purpose of this study has been the development of new functional application with liquid crystal polymer composite films. For example the films were applied a new thermal sensor. In results, best phase separation behaviors turned out liquid crystal/monomer/oilgomer mixture system.

• 한국위성정보통신학회논문지
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• 제1권1호
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• pp.1-4
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• 2006

Ku band의 위성 신호 중계 기술은 수신 신호의 편파 변환을 통해 고층 건물이나 나무, 기타 지형지물에 의해 만들어진 전파 음영지역에서도 위성 방송 서비스의 적용이 가능하다. 본 논문은 안테나 패턴과 사용 주파수 대역에 대해 편파 특성을 만족시키는 고성능 편파 식별 안테나의 제작에 초점을 둔다. 축비 개선과 편파 식별 특성 향상의 관점에서 제작된 안테나는 위성 방송 서비스 중계 시스템에 적합한 특성을 보인다.

• 조명전기설비학회논문지
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• 제18권6호
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• pp.8-13
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• 2004

본 논문에서는 Wollaston prism을 이용한 Shearography에서 수동소자인 두 개의 Waveplate와 편광판의 조합을 통해 각각 90도의 위상천이를 가지는 4개의 스펙클 패턴을 얻고, 이로부터 스펙클의 각 지점에서의 위상을 얻을 수 있는 방법을 제시하고, Jones 행렬을 이용하여 이론적으로 입증하였다.

• 한국통신학회논문지
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• 제25권9B호
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• pp.1534-1541
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• 2000

광섬유고리에 편광제어를 통해 여러 광경로들에 대해서 손실을 조정함으로써 손실이 작은 광경로에서 발진하게 함으로써 발진 파장을 가변시킬 수 있는 편광제어 파장가변 고리형 광섬유레이저를 구현하였다. 1.5mm의 공극을 가진 내부공진편광기를 사용하여 1nm의 종모드간격으로 발진을 일으킬 수 있었고 편광제어기 및 내부공진편광기를 조절해서 1540!1560 nm의 파장가변을 시킬 수 있었다. 또한 실험적으로 나타난 발진특성을 광경로와 복굴절 손실의 개념을 사용하여 발진출력의 파장천이특성을 분석하였다.

• Transactions on Electrical and Electronic Materials
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• 제4권6호
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• pp.21-27
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• 2003

Methods of calculation of polarizers and splitters for visible spectra based on a multi-layer dielectric system are considered. Practical formulas for calculation are given. For example the cases of a splitter calculation when R$\_$s/ > 70% and R$\_$p/$\leq$ 30% or R$\_$s/=R$\_$p/ were considered. The formulas of the effective layers method are of practical use. The optical characteristics of calculated and fabricated polarizers and splitters for 650nm and 780nm wavelengths are presented.

• Journal of the Optical Society of Korea
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• 제9권4호
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• pp.151-156
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• 2005

A spatial-domain Fourier Transform (FT) infrared (IR) spectrometer coupled with a PtSi Schottky­barrier IR detector plane was developed in the spectral range of $2.0-2.5{\mu}m$ for noninvasive measurement of analyte concentrations in cell culture media during cell culture processing. A key optical component of the spectrometer is a Savart plate which is a birefringent polarizer generating coherent two rays for interfering. The spectral resolution of the spectrometer was determined as $71cm^{-1}$ (${\~}0.05{\mu}m$ at $2.5{\mu}m$). Clear IR fringe patterns were imaged on the IR detector plane. The feasibility of the spectrometer for our application was investigated by measuring absorbance spectra of glucose and fetal bovine serum (FBS) which are important compounds in cell culture media. Experiment results show that the spectral quality of glucose and FBS was comparable with the standard spectra acquired with a commercial FT-IR spectrometer, presenting the feasibility of the spectrometer to perform analyte measurement in cell culture media.

• Current Optics and Photonics
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• 제4권4호
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• pp.353-360
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• 2020

Adopting an elaborately designed reflective objective consisting of four mirrors, we have developed a rotating-polarizer-type microspot spectroscopic ellipsometer (SE) with an ultra-small spot size. The diameter of the focused beam, whether evaluated using a direct-image method or a knife-edge method, is less than 8.4 ㎛. After proper correction for the polarizing effect of the mirrors in the reflective objective, we unambiguously determine the dispersion of the complex refractive index and the thickness of monolayer MoS₂ using the measured microspot-spectroellipsometric data. The measured ellipsometric spectra are sensitive enough to identify small variations in thickness of MoS₂ flakes, which ranged from 0.48 nm to 0.67 nm.