• 제목/요약/키워드: diode laser

검색결과 1,017건 처리시간 0.031초

3차원 레이저 스캐너용 ND 필터의 시뮬레이션 (Simulation of ND Filter for Terrestrial Laser Scanner)

  • 양수효;오동근;정중연
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2009년도 춘계학술발표회 논문집
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    • pp.65-73
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    • 2009
  • The terrestrial laser scanner measures the signal delay time of electronic circuit in EDM(Electronic Distance Measurement) Module for distance measurement. To measure signal delay time precisely, transmitting laser beam of terrestrial laser scanner is divided optically. Therefore, 10% of the laser beam power is entered into the electronic circuit and the others go out through lens. But, measure of delay time is severe in the laser scanner system that the laser beam power is changed dynamically by reflectance of a object, because characters like gain of electronic circuit involving APD(Avalanche Photo Diode) and so on are changed by incident laser beam. Therefore, we adapt ND(Neutral Density) filter that has grid pattern to the laser scanner system to keep constant the incident laser beam power. In this paper, we propose the simulation program for efficient design of ND filter pattern. Finally, to affirm simulation program, we conduct the experimental test of simulated ND filter that has linearly transmittance change, and we consider the experiment result.

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측량용 레이저 스캐너의 정밀도 개선을 위한 송신부설계 (Study on terrestrial LIDAR transmitter designed to improve accuracy)

  • 유현국;정중연;오동근;김재순
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2009년도 춘계학술발표회 논문집
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    • pp.41-48
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    • 2009
  • 본 논문에서는 측량용 3차원 레이저 스캐너의 소형화를 위해 광원으로 레이저 다이오드를 사용한 송신부 광학계의 설계를 다루었다. 레이저 다이오드를 사용할 경우 활성층의 특성상 타원형의 Beam shape를 갖게 되고 또한 비점수차를 지닐 수 밖에 없는 문제를 가지고 있다. 본 연구에서는 레이저 다이오드의 비점수차를 제거하기 위하여 시준렌즈와 원통형렌즈를 사용하였으며 1mrad 의 빔 발산각을 갖는 평행광을 만들기 위해 핀홀과 Aperture의 사용을 제안하였다. 이를 바탕으로 실제 제작된 소형 광학계를 사용하여 직경 3.5mm, 0.3mrad 이하의 빔 발산각을 갖는 평행광을 구현하였다.

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다이오드 레이저 노출시간에 따른 Te-doped G $e_{15}Sb_{85}$ 박막의 광학 상수 변화 (The Variation in Optical Constants of Te-doped G $e_{15}Sb_{85}$ Thin Films with Diode-Laser Exposing Time)

  • 김홍석;정진만;이현용;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.30-33
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    • 1997
  • In this paper, we studied the variation in optical constants of Te-doped G $e_{15}$ /$Sb_{85}$ thin films with 7800$\AA$ diode-laser exposing time and power. The reflectances were increased with the increase of laser exposure time and the laser power in all films. Also, the refractive indices of the films after exposing were higher than those of the as-deposited films. Thus, the fast crystallization was caused by addition to the more Te content at the lower lacer power. It was observed that the surface morphologies of the exposed films are higher than those of the as-deposited films by SEM analysis. Therefore, it is considered that the T $e_{0.5}$(G $e_{15}$ /$Sb_{85}$)$_{99.5}$ thin films will show the high contrast ratio and high SNR and have fast erasing time due to crystallization when these films is applied to optical recording materials.terials.s.

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