• Title/Summary/Keyword: Laser Power

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The effect of low power GaAlAs laser stimulation on anti-nociception and spinal neuronal activity related to pain sensation in the polyarthritis of rats (다발성 관절염 실험동물 모델에서 저출력 GaAlAs 레이저 자극의 진통효능 및 통증관련 척수내 신경세포의 활성변화에 관한 연구)

  • Chang, Moon-Kyung;Choi, Young-Duk;Park, Bong-Soon
    • Journal of Korean Physical Therapy Science
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    • v.10 no.1
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    • pp.180-189
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    • 2003
  • The experiments were designated to evaluate the anti-nociceptive effect of low power laser stimulation on acupoint or non-acupoint using arthrogenic solution induced poly arthritis animal model. Evaluation of potential antinociceptive effect of low power laser on arthritis has employed measurements of the foot bending test, the development of either thermal or mechanical hyperalgesia following the arthritis induction. The analysis of thermal hyperalgesia includes Hargreaves's method. Randall-Sellitto test was utilized for evaluating mechanical hyperalgesia. In addition, the antinociceptive effect of low power laser stimulation on arthritis induced spinal Fos expression was analyzed using a computerized image analysis system. The results were summerized as follows: 1. In laser stimulation on acupoint treated animal, laser stimulation dramatically inhibited the development of pain in foot bending test as compared to those of non acupoint treated animal group and non treated animal group. 2. The threshold of thermal stimulation was significantly increased by low power laser stimulation on acupoint as compared to that of non treated control group. 3. Laser stimulation on acupoint dramatically attenuated the development of mechanical hyperalgesia as compared to that of non treated group. 4. Low power laser stimulation on acupoint significantly suppressed arthritis induced Fos expression in the lumbar spinal cord at 3 week post arthritis induction. In conclusion, the results of the present study demonstrated that low power laser stimulation on acupoint has potent anti-nociceptive effect on arthritis. Additional supporting data for an antinociceptive effect of laser stimulation was obtained using Fos immunohistochemical analysis on spinal cord section. Those data indicated that laser stimulation induced antinociception was mediated by suppression of spinal neuron activity in pain sensation.

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Study on a New ACF Bonding Methods in LCD Module Using a High Power Diode Laser (다이오드레이저를 이용한 디스플레이 모듈 내 이방성 전도 필름(ACF) 접합 기술에 관한 연구)

  • Ryu K. H.;Seon M. H.;Nam G. J.;Kwak N. H.
    • Laser Solutions
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    • v.8 no.3
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    • pp.21-26
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    • 2005
  • A bonding process between tape-carrier package and a glass panel with anisotropic conductive film (ACF) has been investigated by making use of high power diode laser as a heat source for cure. The results from modeling of process and from optical properties of layers showed that heat absorbed from polyimide film surface and ACF layer is dominant source of curing during laser illumination. Laser ACF bonding has better bonding quality than conventional bonding in view of peel strength, flatness, pressure unbalance and processing time. New ACF bonding processes by making use of high power diode laser are proposed.

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Blue Laser Generated by Sum Frequency (합주파에 의한 청색레이저 발생)

  • Lee Young-Woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.2
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    • pp.224-227
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    • 2006
  • We have chained 459nm blue laser radiation generated by intracavity sum frequency generation( SFG ) due to the mixing of the 1064 nm laser output of a Nd:YVO4 pumped by diode and the 809nm radiation from higg-power semiconductor laser(500mW). The maximum blue output power of 0.95 mW was obtained using 400 mW input power of semiconductor laser at the type II phase matching condition (${\psi}=90^{\circ}\;{\theta}=90^{\circ}$). The threshold input power of blue laser generation was 120 mW.

A Design and Implement of the Medical Nd:YAG Laser Firmware under in ZCC method

  • Kim, Whi-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.40.3-40
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    • 2001
  • The pulsed Nd:YAG laser is the most commonly used type of solid-state laser in many fields. In material processing and medical treatment, the power density control of a laser beam Considered to be significant, which depends on the flashlamp current pulse width and pulse repetition rate. For general laser power supply to control the laser power density, the secondary of the power transformer is connected to the rectifier and filter capacitor. The output of a rectifier is applied to a switching element in the secondary of the transformer. So power supply is complicated and the loss of switching is considerably. In addition, according to increasing pulse repetition rate, charged energy of energy-storage capacitor bank is not transferred sufficiently to flashlamp, and laser output efficiency decreases. In this study, we have ...

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Characteristics of Output Energy and Optical Parameters in Welding of Braun Tubes by Pulsed Nd:YAG Laser (펄스 Nd:YAG 레이저에 의한 브라운관 부품의 용접시 빔의 출력특성과 광학변수)

  • Kim Jong-Do;Ha Seung-Hyup
    • Laser Solutions
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    • v.8 no.1
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    • pp.27-37
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    • 2005
  • During laser spot welding of the braun tube electron gun, phenomena such as serious spattering and oxidative reaction, etc. were occurred. The spatter occurred from weld pool affects the braun tube, namely it blocks up a very small hole on the shadow mask and causes short circuit between two poles of the electron gun. We guessed that high power density and oxidative reaction are main sources of these problems. So, we studied to prevent and to reduce spatter occurring in spot welding of the braun tube electron gun using pulsed Nd:YAG laser. The characteristics of laser output power was estimated, and the loss of laser energy by optical parameter and spatter was measured by powermeter. The effects of welding parameters, laser defocused distance and incident angle, were investigated on the shape and penetration depth of the laser welded bead in flare and flange joints. From these results, the laser peak power was a major factor to control penetration depth and to occur spatter. It was found that the losses of laser energy by optic parameter and sticked spatter affect seriously laser weldability of thin sheets.

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Influence of process parameters on the kerfwidth for the case of laser cutting of CPS 1N sheet using high power CW Nd:YAG laser (고출력 연속파형 Nd:YAG 레이저를 이용한 CSP 1N 냉연강판 절단시 공정변수의 절단폭에 미치는 영향)

  • Kim Min-Su;Lee Sang-Hoon;Park Hyung-Jun;Yoo Young-Tae;Ahn Dong-Gyu
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.7 s.172
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    • pp.19-26
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    • 2005
  • The objective of this study is to investigate the influence of process parameters, such as power of laser, cutting speed of laser and material thickness, on the practical cutting region and the kerfwidth fer the case of cutting of CSP IN sheet using high power Nd:YAC laser in continuous wave(CW) mode. In order to obtain the practical cutting region and the relationship between process parameters on the kerfwidth, several laser cutting experiments are carried out. The effective heat input is introduced to consider the influence of power and cutting speed of laser on the kerfwidth together. From the results of experiments, the allowable cutting region and the relationship between the effective heat input and kerfwidth fur the case of cutting of CSP 1N sheet using high power CW Nd:YAG laser have been obtained to improve the dimensionalaccuracyofthecutarea.

Thermal Lens Compensation in a Fiber-Coupled Laser-Diode Pumped Ceramic Nd:YAG Laser (광섬유 연결 반도체레이저 여기 세라믹 Nd:YAG 레이저에서 열렌즈 효과의 보상)

  • Kim, Duck-Lae;Kim, Yeong-Sik;Kim, Byung-Tai
    • Korean Journal of Optics and Photonics
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    • v.18 no.3
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    • pp.208-215
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    • 2007
  • A fiber-coupled laser-diode pumped ceramic Nd:YAG laser for compensating the thermal tensing effect was developed. The thermal tensing effect was compensated using a convex lens, which was 25 mm away from the laser rod, with a focal length of 30 mm and an effective clear aperture of 22 mm. Without a compensator, the laser output power decreased suddenly above a pump power of 6 W. Using a compensator, the laser output power increased linearly according to the pump power. The beam propagation factor $M^{2}$ was 2.4 under a pump power of 12 W.

200-W Continuous-wave Thulium-doped All-fiber Laser at 2050 nm

  • Shin, Jae Sung;Cha, Yong-Ho;Chun, Byung Jae;Jeong, Do-Young;Park, Hyunmin
    • Current Optics and Photonics
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    • v.5 no.3
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    • pp.306-310
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    • 2021
  • A 200-W continuous-wave thulium-doped all-fiber laser at 2050 nm was developed with a master oscillator power amplifier configuration. For the master oscillator, a single-mode thulium-doped fiber laser was built with fiber Bragg gratings. The operating power of the oscillator was 10.1 W at a pump power of 20.9 W, and the slope efficiency was measured to be 53.0%. All emitted wavelengths of the oscillator were located between 2049.2 nm and 2049.9 nm, and no other peaks in different wavelength ranges were observed. The maximum output power of the final amplified beam was 204.6 W at a pump power of 350.4 W. The slope efficiency of the amplifier was measured to be 58.4%.

Laser Cutting of Thick Diamond Films Using Low-Power Laser (저 출력 레이저를 이용한 다이아몬드 후막의 절단)

  • 박영준;백영준
    • Journal of the Korean Ceramic Society
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    • v.37 no.2
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    • pp.140-144
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    • 2000
  • Laser cutting of thick diamond films is studied using a low-power(10 W) copper vapor laser. Due to the existence of the saturation depth in laser cutting, thick diamond films are not easily cut by low-power lasers. In this study, we have adopted a low thermalconductivity underlayer of alumina and a heating stage (up to 500$^{\circ}C$ in air) to prevent the laser energy from consuming-out and, in turn, enhance the cutting efficiency. Aspect ratio increases twice fromm 3.5 to 7 when the alumina underlayer used. Adopting a heating stage also increases aspect ratio and more than 10 is obtained at higher temperatures than 400$^{\circ}C$. These results show that thick diamond films can be cut, with low-power lasers, simply by modifying the thermal property of underlayer.

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