• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.4
• /
• pp.531-538
• /
• 2006

Grating is an installed structure on the road for drain. This paper proposes a new product which can prevent the accumulation of earth and sand through the improvement of Grating structure. There were usually harmful insects and bad smell because of accumulated garbage in the frame of previous product. The product had a reverse-flowing sewage due to the bad draining in case of rain. The whole thing of the existing Grating installed with the one set of frame and main body should be changed when it was damaged. This study is to develop a structure which can separate grating main body from frame and grating main body can equip and separate after fixing frame to the manhole with cement. also install jig for the loss prevention and change for the better.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.5
• /
• pp.922-926
• /
• 2010

We have investigated the grating coupled surface plasmon resonance (GC-SPR) sensors using ZnO nano-grating structures to enhance the sensitivity of an SPR sensor. The GC-SPR sensors were analyzed using the finite-difference time-domain method. The optimum resonance angles of 49 degrees are obtained in the 150 nm wide grating structure with a period of 300 nm for the ZnO thickness of 30 nm. Then, the ZnO nano-grating patterns were fabricated by using laser interference lithography. The measured resonance angle of nano-grating patterns was around 49 degrees. Here, an enhanced evanescent field is obtained due to the surface plasmon on the edge of the bandgap when the ZnO grating structures are used to excite the surface palsmon.

• Applied Science and Convergence Technology
• /
• v.24 no.6
• /
• pp.250-253
• /
• 2015

High contrast grating (HCG) is the structure made up of the sub-wavelength grating of high-index and the surrounding layer of low-index, which reveals high contrast between two materials. Its advantages include high reflectivity over a broad bandwidth, polarization and wavelength selectivity, optical high-Q resonator, and phase modulation. In this work, the HCG structure comprising of indium tin oxide (ITO) and Silicon (Si), for the surrounding layer and the grating layer respectively, was studied. Its theoretical model was established, and transmittance, phase and optical behavior were calculated by rigorous coupled-wave analysis and finite element method. Furthermore, the established structure was fabricated to validate its feasibility. The fabricated structure shows the focusing capability whose length is about $10{\mu}m$, and the feasibility of the structure was demonstrated. It is also meaningful that ITO layer can contribute to the fabrication of the HCG structure, leading to enable the structure to be electrical-driven.

• Journal of Korean Association for Spatial Structures
• /
• v.8 no.6
• /
• pp.95-100
• /
• 2008

The object of this paper is to verify possible to monitor the deformation of cable in the tensegrity structure. Also, always monitoring system of tensegrity structure using Fiber Bragg Grating Sensor is described. We carry out experiments with measuring deformation of cable in the tensegrity structure based on loading conditions. In the result of experiment, the Fiber Bragg Grating Sensors shows accurate response to the loading conditions. Therefore, we can make sure the possibility of Fiber Bragg Grating Sensor in health monitoring of the cable structure like tensegrity structure.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.6
• /
• pp.189-196
• /
• 1996

We have studied sngle-frequency yield of 1.55${\mu}$m DFB lasers with uniform sinusoidal grating using an effective index transfer matrix method considering both threshold gain difference and spatial hole-burning effect. Optimum grating height and mirror reflectivities that maximize the single-frequency yield are found for a low-reflection (LR)/high-reflection(HR) mirror structure and a LR/as-cleaved miror structure for an assumed basic waveguide structure. LR/HR structure has a high yield of about 80% in a narrow range of grating height while LR/as-cleaved mirror structure has a low yield of about 50% in a relatively wide range of grating height. The effect of the low-reflection facet reflectivity is also studied.

• Korean Journal of Optics and Photonics
• /
• v.7 no.4
• /
• pp.370-374
• /
• 1996

A Superstructure Grating(SSG) Distributed-Bragg-Reflector(DBR) laser has a broad tuning range with a good mode suppression ratio. However, gaps of channel are observed in the wavelength-tuning characteristics of an SSGDBR laser which employs linearly-chirped DBR mirrors. We found by numerical simulation that the gaps may be attributed to the nonuniform reflection-peak heights of a linearly-chirped DBR mirrors. We propose a nonlinearly chirped grating DBR mirror structure that makes reflection-peak heights almost uniform. Therefore a nonlinearly chirped grating structure can be employed in an extended tuning range semiconductor laser to achieve gap-free tuning and low threshold current operation simultaneously.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.4
• /
• pp.713-720
• /
• 2007

Grating is an installed structure on the road for drain. This paper proposes a new product which can prevent the accumulation of earth and sand through the improvement of Grating structure. There were usually harmful insects and bad smell because of accumulated garbage in the frame of previous product. The whole thing of the existing. This study is to separate grating from body. Also body structure consists of frame and box for collecting sewage. Thus, earth and sewage are prevented from accumulating in the drain main hole. The contents of this study is designed safely after structure analysis and vibration shape analysis about new products.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.3
• /
• pp.311-317
• /
• 2019

We first numerically analyzed the characteristics of a silicon-based grating structure for beam steering. The analysis includes the basic principle of the grating structure according to the wavelength, peak radiation angle, radiation efficiency, and full-width at the half maximum(FWHM) of the radiation angle. Based on the analysis, we propose a silicon-based grating structure integrated with distributed Bragg reflector(DBR) to obtain a high radiation efficiency and narrow beam width simultaneously. We performed the numerical optimization of the radiation efficiency and FWHM of the radiation angle according to the DBR position. By the design optimization using the proposed grating structure compatible with the complementary metal-oxide semiconductor(CMOS) process, we achieved a maximum radiation efficiency of 87.1% and minimum FWHM of radiation angle of $4.68^{\circ}$.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.24 no.4
• /
• pp.553-558
• /
• 1987

A design method of dielectric image-guide grating structures which are applicable for the millimeter-wave system is presented. A dielectric image-guide grating with notches in the sides and also another grating with notches in the top have been designed, fabricated and tested with TM-and TE-mode excitations. From the esperimental results the relatin between TM-TE mode symmetry in the grating structure has been investigated.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.22 no.2
• /
• pp.129-134
• /
• 2022

The resonant bio-sensor of bi-level grating structure with mushroom profile has been designed for operating in the near-infrared (NIR) wavelength range under transverse electric (TE) polarization. The rigorous modal transmission-line theory (MTLT) is applied to determine the optical characteristics, and the reflection resonance of the grating structure is analyzed by varying their geometrical parameters. The numerical result shows that an excited sharp Fano resonance (FR), which does not occur in single layer grating, is demonstrated. The relationship between structure parameters of bi-level grating and the reflectance spectrum in order to guarantee the appearance of FR in the designed structure is fully investigated. An optical bio-sensor with a potential sensitivity of 112.9~214.3 deg/RIU and 447 nm/RIU is designed based on the proposed structure. The proposed mushroom profile may serve as a powerful sample for the design of optical bio-sensors with a wide range of applications.