• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 추계학술대회논문집
• /
• pp.61-64
• /
• 2004

Recently, as the requirements of several mobile products come to the front, to cope with the market needs, various mobile storage applications have appeared. Therefore, the core components and technologies for mobile optical disc drives have been developed continuously. In case of the optical storage, the small sized optical pickup is necessary to realize the mobile optical disc drive, because the optical pickup height is determined by the optical parts and an actuator. In this paper, we propose the optical pickup actuator using the horizontally arranged magnetic circuit, and apply to 5mm height Small Form-factor Optical Drive.

• 한국광학회지
• /
• 제20권6호
• /
• pp.361-365
• /
• 2009

본 연구에서는 패턴 빔을 이용하여 표면이 거친 물체의 단차를 비접촉 방식으로 측정 하는 방법에 대하여 연구하였다. 본 연구에 사용된 방법은 장치가 매우 간단하고 스페클 노이지가 영상에 미치는 영향이 작아 재현성 면에서 매우 우수하였다. 특히 기준면에 문양이 없는 경우에는 기존의 자동 초점 측정 장치로는 측정하기 어려우나, 본 연구 방법에 의해 측정이 가능함을 보였다. 그리고 측정 시간이 매우 짧고 재현성이 좋으며 장치가 간단하여 산업 현장에서 응용하기 적절한 방법이다.

• 접착 및 계면
• /
• 제23권2호
• /
• pp.39-43
• /
• 2022

디스플레이, 태양전지와 같이 전기를 빛으로, 또는 빛을 전기로 변환시켜주는 광전자소자는 효율 향상을 위하여 빛의 거동 제어가 매우 중요하다. 즉, OLED의 경우 내부 빛 제어를 통해 더 많은 빛이 외부로 나갈 수 있도록 유도해 줄 때 발광효율을 향상시킬 수 있으며, 외부 빛 제어를 통해 광흡수층에서의 광경로를 증대시킬 경우 태양전지의 에너지 변환효율을 증가시킬 수 있다. 본 연구에서는 이러한 광거동 제어가 가능한 구조로서 주름구조에 대한 연구를 진행하였으며 응력 해소 시간을 제어하여 구조의 주기와 높이를 독립적으로 제어하고자 하였다. 주기와 높이의 변화가 광거동에 어떠한 영향을 미치는지 살펴보기 위하여 일정한 주기에서 높이 변화 및 유사한 높이에서 주기 변화에 따른 자외선/가시광선 분광분석(UV/Vis spectroscopy)을 실시하였으며 구조의 종횡비가 클수록 직진광의 비율이 낮고 분산광의 비율이 높음을 확인하였다. 이를 통해 광경로 변화 및 광경로 증가를 위하여 큰 종횡비의 주름구조가 요구됨을 확인할 수 있었다.

• 정보저장시스템학회논문집
• /
• 제1권1호
• /
• pp.67-72
• /
• 2005

This study proposes a design methodology to determine the optimum configurations of the optical flying head (OFH) for near-field recording systems. Since the OFH requires stricter static and dynamic characteristics of slider air-bearings within an optical tilt tolerance over the entire recording band, an optimum design to keep the focusing and tracking ability stable is essential. The desired flying characteristics considered in this study are to minimize the variation in flying height between the SIL and the disk from a target value, satisfying the restriction of the minimum flying height, to keep the pitch and roll angles within an optical tilt tolerance, and to ensure a higher air-bearing stiffness. Simulation results demonstrate the effectiveness of the proposed design methodology by showing that the static and dynamic flying characteristics of the optimally designed OFH are enhanced in comparison with those of the initial. The gap between the SIL and the disk can be kept at less than 100 nm even if the optical tilt tolerance of the SIL is considered.

• 한국도로학회논문집
• /
• 제17권4호
• /
• pp.63-68
• /
• 2015

PURPOSES : A study on the efforts to minimize the road traffic noise has been underway. An attempt has been made to measure the noise level using a noise map; however, the attempt is limited to certain areas only. In general, a noise barrier is employed to prevent road traffic noise; however, unplanned noise barriers developed without considering the surrounding environment, including excessively high walls, cause problems such as infringement on prospect right. Noise ceiling at daytime in Korea is 68 dB(A), which is relatively higher than in other countries. METHODS: The noise barrier used mainly for road noise reduction was analyzed to estimate the optimal height. Related variables such as road width, the height of the upper part, distance to the building, and angle (for instance, $30^{\circ}$). RESULTS : A formula to calculate the optical height of the noise barrier, considering the road environment (i.e., parameters such as road width and distance to building), was developed in this study in an attempt to mitigate the noise generated from the road. CONCLUSIONS : The formula to calculate the noise barrier is expected to lead to cost saving, accurate installation of barriers, and protection of the right of prospect.

• 마이크로전자및패키징학회지
• /
• 제26권2호
• /
• pp.55-58
• /
• 2019

최근 표면 플라즈몬 효과는 광 신호 향상에 중요하게 대두되고 있는 분야로써, 약한 광학적 신호를 증가시킴에 따라 바이오 분야나 뉴로사이언스에 매우 중요한 분야로 대두되었다. 플라즈모닉 구조를 제작하기 위해선 나노 구조의 크기 높이 그리고 입사광의 입사각 등 다양한 변수들이 존재하는데 본 논문에서는 플라즈모닉 나노구조의 제작을 위한 은 증착 높이에 따른 플라즈모닉 나노구조의 광학적 특성에 대한 연구를 진행하였다. 은 증착은 플라즈모닉 효과를 보기 위해 다양하게 사용하고 있는 금속으로 특정 파장에 반응을 보기 위해 제작한 구조 형태와 유사한 구조를 시간영역 유한차분(FDTD)법을 통해 광 특성을 예측하여, 최종적으로 제작한 구조의 은 나노 입자 부근에 에너지가 집중되는 결과를 확인하였다.

• Journal of the Optical Society of Korea
• /
• 제20권2호
• /
• pp.228-233
• /
• 2016

In this paper, we propose a nonlinear maximum average correlation height (MACH) filter for information authentication of photon counting double random phase encryption (DRPE). To enhance the security of DRPE, photon counting imaging can be applied because of its sparseness. However, under severely photon-starved conditions, information authentication of DRPE may not be implemented successfully. To visualize the photon counting DRPE, a three-dimensional imaging technique such as integral imaging can be used. In addition, a nonlinear MACH filter can be utilized for helping the information authentication. Therefore, in this paper, we use integral imaging and nonlinear MACH filter to implement the information authentication of photon counting DRPE. To verify our method, we implement optical experiments and computer simulation.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.770-774
• /
• 2003

We propose the re-design method of modal parameters to depress the 2nd resonance peak of the ultra-slim-height optical pick-up actuator. With the addition of tile counter mode near the 2nd resonance frequency, we can achieve the gain margin which is sufficient to meet the system requirement. It would alleviate the burden of the additional filter for a high-speed drive.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2003년도 춘계학술대회논문집
• /
• pp.1165-1169
• /
• 2003

This paper presents an approach to optimally design the air-bearing surface (ABS) of the optical flying head for near-field recording technology (NFR). NFR is an optical recording technology using very small beam spot size by overcoming the limit of beam diffraction. One of the most Important problems in NFR is a head disk interface (HDI) issue over the recording band during the operation. A multi-criteria optimization problem is formulated to enhance the flying performances over the entire recording band during the steady state. The optimal solution of the slider, whose target flying height is 50 nm, is automatically obtained. The flying height during the steady state operation becomes closer to the target values than those fur the initial one. The pitch and roll angles are also kept within suitable ranges over the recording band. Especially, all of the air-bearing stiffness are drastically increased by the optimized geometry of the air bearing surface.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2004년도 하계학술발표회
• /
• pp.28-29
• /
• 2004

Optical wireless mobile communications have the potential to provide wide bandwidth and security . We have proposed and designed the 2-dimensional tracking optical receiver systems for optical wireless mobile communication. The receiver system consist of 4${\times}$4 photodiode array can receive optical signal from the transmitter. The room size is 5${\times}$5m$^2$ and the room height is 3m.