• Journal of the Optical Society of Korea
• /
• 제15권2호
• /
• pp.128-131
• /
• 2011

After the successful extension of the rotating planar waveguide model to Wave Optics, where a clear identification between the angular velocity of one hypothetical waveguide and the phase differences between two points on the path of one bounded mode was found, an application of the model to explain the interference theory is presented. We demonstrate that, for two bounded modes to create an interference pattern, a constrain to the relative parameters among both is imposed by the fiber optics. This result, not reported in the literature up to date, provides a new horizon to understand the interaction light-light when propagated within optical fibers.

• 한국광학회지
• /
• 제16권3호
• /
• pp.196-200
• /
• 2005

[ $0.75delta\%$ ]의 평판광회로(PLC;Planar Lightwave Circuit)소자의 설계 및 제작기술을 가지고 저손실과 높은 누화율을 가진 파장 다중화 및 역다중화 소자를 개발하였다. C-band AWG(Arrayed Waveguide Grating)에서의 삽입손실은 2.503이하, 누화율은 35dB이상, 균일도는 1dB이하이며 L-band에서는 Vernier 디자인을 적용하여 ITU-T의 파장 정확도가 0.04nm이하가 되도록 제작하였다.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
• /
• pp.136-136
• /
• 2003

In fiber optic networks, system size and cost can be significantly reduced by development of optical components through planar optical waveguides. One important step to realize the compact optical devices is to develop planar optical amplifier to compensate the losses in splitter or other components. Planar amplifier provides optical gain in devices less than tens of centimeters long, as opposed to fiber amplifiers with lengths of typically tens of meters. To achieve the same amount of gain between the planar and fiber optical amplifier, much higher Er doping levels responsible for the gain than in the fiber amplifier are required due to the reduced path length. These doping must be done without the loss of homogeniety to minimize Er ion-ion interactions which reduce gain by co-operative upconversion. Sol-gel process has become a feasible method to allow the incorporation of Er ion concentrations higher than conventional glass melting methods. In this work, Er-doped $SiO_2$-A1$_2$ $O_3$ films were prepared by two different method via sol -Eel process. Tetraethylorthosilicate(TEOS)/aluminum secondary butoxide [Al (OC$_4$ $H_{9}$)$_3$], methacryloxypropylcnethoxysaane(MPTS)/aluminum secondary butofde [Al(OC$_4$ $H_{9}$)$_3$] systems were used as starting materials for hosting Er ions. Er-doped $SiO_2$-A1$_2$ $O_3$ films obtahed after heat-treating, coatings on Si substrate were characterized by X-ray din action, FT-IR, and N-IR fluorescence spectroscopy. The luminescence properties for two different processing procedure will be compared and discussed from peak intensity and life time.

• 한국전기전자재료학회논문지
• /
• 제18권12호
• /
• pp.1106-1110
• /
• 2005

We fabricated (110) silicon hard master by using anisotropic wet etching for embossing. The etching chemical for the silicon wafer was a TMAH $25\%$ solution. The anisotropic wet etching produces a smooth sidewall surface and the surface roughness of the fabricated master is about 3 nm. After spin coating an organic-inorganic sol-gel hybrid material on a silicon substrate, we employed hot embossing technique operated at a low pressure and temperature to form patterns on the silicon substrate by using the fabricated master. We successfully fabricated the multi-mode planar optical waveguides showing low propagation loss of 0.4 dB/cm. The surface roughness of embossed patterns was uniform for more than 10 times of the embossing processes with a single hydrophobic surface treatment of the silicon hard master.

• 한국광학회지
• /
• 제18권3호
• /
• pp.190-195
• /
• 2007

광 평면 유전체 기판 위에 형성된 금속격자구조의 누설특성을 이용한 새로운 광 결합용 필터를 제안하였고, Bragg 조건들을 모드 전송선로 이론을 사용하여 정확하게 분석하였다. 수치해석 결과, 유전체격자구조로 구성된 기존의 DFB는 전송 모드들의 피드백특성에 기인한 차단대역을 형성하지만 금속격자구조는 누설파특성에 기인한 차단대역을 형성하는 것으로 나타났다. 결국, 누설파 필터특성을 적용한 광 결합용 필터는 LD나 광섬유와 같은 광통신용 소자들과 집적이 가능함을 보였다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.67-67
• /
• 2012

Graphene, two-dimensional one-atom-thick planar sheet of carbon atoms densely packed in a honeycomb crystal lattice, exhibits fascinating electrical properties, such as a linear energy dispersion relation and high mobility in addition to a wide-range optical absorption and high thermal conductivity. Graphene's outstanding tensile strength allows graphene-based electronic and photonic devices to be flexible, bendable, or even stretchable. Recently many groups have reported high performance electronic and optoelectronic devices based on graphene materials, i.e. field-effect transistors, gas sensors, nonvolatile memory devices, and plasmonic waveguides, in which versatile properties of graphene materials have been incorporated into a flexible electronic or optoelectronic platform. However, there are several fundamental or technological hurdles to be overcome in real applications of graphene in electronics and optoelectronics. In this tutorial we will present a short introduction to the basic material properties and recent progresses in applications of graphene to electronics and optoelectronics and discuss future outlook of graphene-based devices.

• 한국고분자학회:학술대회논문집
• /
• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
• /
• pp.309-309
• /
• 2006

Latest developments on hybrid nanostructured materials fabricated by applying self-assembly strategies on organic/inorganic nanotemplates are discussed. Within this frame, numerous functional nanomaterials including arrays of composite metal/semiconductor nanoparticles, planar waveguides and functional multilayer thin films are generated using self-assembled polymers as templates or building blocks. In particular, surface plasmon resonance based optical sensing is employed to investigate nanofabrication processes occurring in nanoscale dimention. We also suggest unprecedented pathways to hybrid supramolecular multilayer nanoarchitectures in 1D or 2D geometry via layer-by-layer self-assembly.

• Journal of the Optical Society of Korea
• /
• 제17권6호
• /
• pp.538-542
• /
• 2013

We propose a simple model to elucidate the dispersion behavior of spiraling modes on silver nanowire by finding correspondence parameters and building a simple equivalent relationship with the planar insulator-metal-insulator geometry. The characteristics approximated for the proposed structure are compared with the results from an exact solution obtained by solving Maxwell's equation in cylindrical coordinates. The effective refractive index for our proposed equivalent model is in good agreement with that for the exact solution in the 400-2000 nm wavelength range. In particular, when the radius of the silver nanowire is 100 nm, the calculated index shows typical improvements; the average percentage error for the real part of the effective refractive index is reduced to only 5% for the $0^{th}$ order mode (11.9% in previous results) and 1.5% for the $1^{st}$ order mode (24.8% in previous results) in the 400-800 nm wavelength range. This equivalent model approach is expected to provide further insight into understanding the important behavior of nanowire waveguides.

• ETRI Journal
• /
• 제27권1호
• /
• pp.89-94
• /
• 2005

This paper describes a low-loss, compact, 40-channel arrayed waveguide grating (AWG) which utilizes a monolithically integrated spot-size converter (SSC) for lowering the coupling loss between silica waveguides and standard single-mode fibers. The SSC is a simple waveguide structure that is tapered in both the vertical and horizontal directions. The vertically tapered structure was realized using a shadow-mask etching technique. By employing this technique, the fabricated, 40-channel, 100 GHz-spaced AWG with silica waveguides of 1.5% relative index-contrast showed an insertion-loss figure of 2.8 dB without degrading other optical performance.

• 대한전자공학회논문지SD
• /
• 제38권12호
• /
• pp.36-43
• /
• 2001

${\lambda}$/4 천이영역을 갖는 평면 DFB 도파로의 광학적특성을 분석하였다. 그 도파로의 필터특성과 공진특성을 정확히 분석하기 위하여 Floquet 이론과 Babinet 원리에 기초한 새로운 모드 전송선로 이론을 유도하였다. 수치해석 결과, 본 논문에서 제시한 해석법은 ${\lambda}$/4 천이영역을 갖는 평면 DFB 도파로의 필터 특성과 공진특성을 간단히 해석할 수 있는 알고리즘을 제공하며, 다른 근사적 해석법들에서 얻을 수 없는 새로운 물리적 특성을 보여 주었다.