• 제목/요약/키워드: LASER Diode

검색결과 1,015건 처리시간 0.03초

다이오드 레이저를 이용한 광흡수 농도 계측 기법 (I) (Species Concentration Measurement Using Diode Laser Absorption Spectroscopy (I))

  • 안재현;김용모;김세원
    • 한국연소학회지
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    • 제9권3호
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    • pp.27-35
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    • 2004
  • Diode laser absorption sensors are advantageous because they may provide fast, sensitive, absolute, and selective measurements of species concentration. These systems are very attractive for practical applications owing to its compactness, resonable cost, robustness, and ease of use. In addition, diode lasers are fiber-optic compatible and thus enable simultaneous measurements of multiple species along a line-of-sight. Recent advances of room-temperature, near-IR and visible diode laser sources for telecommunication, optical data storage applications make it possible to be applied for combustion diagnostics based on diode laser absorption spectroscopy. Therefore, combined with fiber-optics and high sensitive detection strategies, compact and portable sensor systems are now appearing for variety of applications. The objectives of this research are to develope a new gas sensing system and to verify feasibility of this system. Wavelength and power characteristics as a function of injection current and temperature are experimentally found out. Direct absorption spectroscopy has been demonstrated in these experiments and has a bright prospect to this diode laser system.

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Histological Change and Collagen Formation on Laser Wounded Rat using 808 nm Diode Laser and $CO_2$ Laser

  • ;;;안진철
    • 대한의생명과학회지
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    • 제15권1호
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    • pp.81-86
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    • 2009
  • Lasers are necessity in our life related to the fields of medicine and cosmetic surgery. With 808 nm diode laser and $CO_2$ laser, we made some wounds on a dorsum of rat by laser irradiation. All of irradiations shows thermal effects on the whole region of skin tissues. They make wound damage depending on laser power and irradiation time. Because a collagen is plays an important role in tissue repair, we studied collagen accumulation in wound tissue. For wound healing, collagen accumulation was found in the near region of damage in epidermis and dermis layer of the rat skin. In case of the quantitative analysis of collagen in wound tissue, the amount of collagen in wound tissue by $CO_2$ laser irradiation is higher than that of 808 nm diode laser irradiation. And re-epithelialization was significantly faster in wound by $CO_2$ laser irradiation compared with that of 808 nm diode laser irradiation.

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레이저 다이오드 Mirror면의 Anti-Reflection 코팅 박막 제작 및 특성 분석 (The Manufacture and Properties Analysis of Anti-Reflection Coating Thin Film of Laser Diode Mirror)

  • 기현철;김선훈;김상택;김효진;김회종;홍경진;민용기;조재철;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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    • pp.103-106
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    • 2006
  • Semiconductor laser diode has a reflective facet in a both-ends side fundamentally. Laser performance for improving, Anti-Reflection and High-reflection coating on the facet of semiconductor laser diode. To prevent internal feedback from both facets for realizing superluminescent diode and reducing the reflection-induced intensity noise of laser diode, it's key techniques are AR/HR coatings. In the study AR coating film were manufactured by Ion-Assisted Deposition(IAD) system. Then manufactured coating film measurement electrical properties(L-I-V, Se, Resistor) and Optical properties (wavelength FFP)

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780nm Monolithic 4-Beam 레이저 다이오드의 Droop 특성 개선 (The Improvement of Droop Characteristic of 780nm Monolithic 4-Beam Laser Diode)

  • 홍현권;김지호;지유상;성영운;이상돈
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.285-287
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    • 2009
  • When the laser diode is operated with continuous current, the light intensity from the laser diode deceases with time due to the temperature rise in the active layer. The phenomena, which is often called as DROOP, should be minimized in order to be used as a light source for the laser beam printer. We experimently examined the influences of the laser parameters such as threshold current, differential quantum efficiency on droop. It was found that decreasing the differential quantum efficiency of the laser diode is the effective way to minimize droop.

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치주치료 후 지각과민 감소를 위한 다이오드 레이저와 Ms coat 처치 직후 임상적 효과 비교 (The comparison clinical study effect of Diode Laser & Ms coat usage for dentinal hypersensitivity following Periodontal therapy)

  • 최현복;홍기석;정진형;임성빈
    • Journal of Periodontal and Implant Science
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    • 제37권2호
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    • pp.201-208
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    • 2007
  • The purpose of this study was to evaluate the effect of diode laser & desensitizing agents to overcome hypersensitizing root surfaces problem after periodontal treatment. 20 patients(60 teeth) presented were volunteered in this study. Diode laser & MS coat was respectively applied on hypersensitizing root surfaces after periodontal treatments. Following application they were evaluated immediately. The results were as follows: 1. The frequency and degree of root surface hypersensitivity levels were measured by the sequence of tactile and air stream. 2. Reduction of root surfaces hypersensitivity by tactile were for Diode laser and Ms coat application respectively $3.0294{\pm}2.0224$ and $3.2692{\pm}1.6139$. 3. Reduction of root surfaces hypersensitivity by air stream were for Diode laser and Ms coat apapplication respectively $3.0294{\pm}2.0224$ and $2.2692{\pm}1.6139$. 4, It could be said that Diode Laser and Ms coat application were significantly effective in reducing dentin hypersensitivity as far as concerned effect, Ms coat applicatio showed more effective than Diode laser. In conclusion, both methods were significantly effective in reducing dentinal hypersensitivity. Therefore, it was recommended that Diode laser and desensitizing agents could be used routinely for patients dentinal hypersensitivity following periodontal treatment.

DH Laser Diode의 전기적 포화현상에 관한 이론적 해석 (Theoretical Analysis of the Electrical Saturation Behavior of the DH Laser Diode)

  • 박영규;권영기
    • 대한전자공학회논문지
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    • 제15권5호
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    • pp.34-38
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    • 1978
  • rate equation을 사용하여 DH Laser Diode에서 나타나는 전기적 포화현상이 이론적으로 설명되었다. Carrier density는 threshold 이후에 서서히 ns에 접근해가며 이론적으로 계산된 곡선과 예측된 ΔVj는 전에 보고된 실험결과를 정확히 설명한 수 있음이 입증되었다. carrier saturation factor kβ를 제안하였으며 kβ는 L.D의 이상성을 결정하는 중요한 factor 임이 설명되었다. kβ와 β와의 관계를 통해 β가 작으면 작을수록 diode의 특성은 이상적 diode에 가까와짐이 밟혀졌다.

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3mW 850nm Laser Diode가 Rat BM-Cell에 미치는 효과 (The effect of 3mW 850nm Laser Diode on RAT BM-cell)

  • 천민우;김성환;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.514-515
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    • 2008
  • Low level laser therapy has various therapy effects. This paper performed the basic study for developing the Low Level Laser Therapy Equipment for medical treatment. The apparatus has been fabricated using the laser diode and microprocessor unit. This equipment was fabricated using a micro-controller and a laser diode, and designed to enable us to control light time, frequency and so on. In this study, the designed device was used irradiation to find out how 850 nm laser diode affected the cell proliferation of RAT bone-marrow cells. Experiment was performed to irradiation group and non-irradiation group for Rat bone marrow cells. MTT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring 590 nm transmittance of micro plate reader. As a result, the cell increase of Rat bone marrow cells was verified in irradiation group as compared to non-irradiation group. The fact that specific wavelength irradiation has an effect on cell vitality and proliferation is known through this study.

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1.48$\mu\textrm{m}$ Diode Laser로 보조 부화처리 후 이식된 생쥐배의 정상임신에 관한 연구 (Normal Pregnancy of Mouse Embryos Transferred after Assisted Hatching by a 1.48$\mu\textrm{m}$ Diode Laser)

  • 김은영;이봉경;남화경;이금실;윤산현;박세필;정길생;임진호
    • 한국가축번식학회지
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    • 제22권3호
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    • pp.287-292
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    • 1998
  • 본 실험은 1.48$\mu\textrm{m}$ diode laser의 인간배에 대한 적용 가능성 여부를 조사하기 위한 예비실험으로, 체외생산된 생쥐배에 1.48$\mu\textrm{m}$ diode laser를 이용한 zona pellucida (ZP) drilling 처리가 배의 부화와 체내발달에 효과적인지를 조사하고자 실시하였다. 그 결과는 다음과 같다. 발달단계가 상이한(4-세포기배, 배반포기배) 생쥐배에 laser ZP drilling 처리한 후 72시간 (배반포기배) 또는 120시간 (4-세포기배) 동안 배양하였던 바, laser ZP drilling 처리를 받은 배반포기배의 부화율(81.8%)이 대조군 (54. 2%)이나 laser ZP drilling 처리를 받은 4-세포기배 (45.5%) 보다 유의하게 높게 나타났다(p<0.05). 또한, laser ZP drilling된 배반포기배를 가임신이 유도된 대리모에 이식하였던 바, 처리군 (48.7%)의 착상율이 대조군 (43.6%)보다 약간 높게 나타났다. 한편, 임신된 대리모 일부는 분만을 유도하였던 바, 태어난 모든 새끼는 처리군에 관계없이 정상적인 염색체수 (n=40), 정상적인 성장과 생식기능을 나타내었다. 이러한 결과는 1.48$\mu\textrm{m}$ diode laser를 이용한 ZP drilling이 생쥐배의 부화를 증진시키고 정상적인 임신을 유도할 수 있어 인간배에 대한 적용 간으성을 시사한다고 하겠다.

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Laser Diode Tester 개발과 비젼 피드백을 이용한 위치 보정 (Development of Laser Diode Tester and Position Compensation using Feedback with Machine Vision)

  • 김재희;유철우;박상민;유범상
    • 한국공작기계학회논문집
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    • 제13권4호
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    • pp.30-36
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    • 2004
  • The development of LD(Laser Diode) tester and its control system based on the graphical programming language(LabVIEW) is addressed. The ill tester is used to check the optic power and the optic spectrum of the LD Chip. The emitter size of LD chip and the diameter of the Detector(optic fiber and photo diode) are very small, therefore the test device needs high accuracy. But each motion part of the test device could not accomplish high accuracy due to the limit of the mechanical performance. So, an image processing with machine vision is proposed to compensate for the error. By adopting our method we can reduce the error of position within $\pm$5$\mu\textrm{m}$.

파장변조 광흡수 분광법을 이용한 농도 계측 기법 (Species Concentration Measurement Technique Using Wavelength Modulation Absorption Spectroscopy)

  • 안재현;김용모
    • 한국분무공학회지
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    • 제9권4호
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    • pp.67-76
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    • 2004
  • Diode laser absorption sensors are advantageous because they may provide fast, sensitive, absolute, and selective measurements of species concentration. These systems are very attractive for practical applications owing to its compactness, reasonable cost, robustness, and ease of use. In addition, diode lasers we fiber-optic compatible and thus enable simultaneous measurements of multiple species along a line-of-sight. Recent advances of room-temperature, near-IR and visible diode laser sources for telecommunication, optical data storage applications make it possible to be applied for combustion diagnostics based on diode laser absorption spectroscopy. Therefore, combined with fiber-optics and high sensitive detection strategies, compact and portable sensor systems are now appearing for variety of applications. The objectives of this research are to develop new gas sensing system and to verify feasibility of this system. Wavelength modulation spectroscopy has been demonstrated in these experiments and has a bright prospect to this diode laser system.

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