• Title/Summary/Keyword: High-intensity laser

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High Intensity Laser for Laser Acupuncture Application (침구치료에 사용되는 고출력 레이저에 대한 고찰)

  • Yang, Chang-Sop;Sun, Seung-Ho;Jang, In-Soo
    • Korean Journal of Acupuncture
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    • v.28 no.3
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    • pp.1-12
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    • 2011
  • Objectives : The purpose of this study is to review laser acupuncture studies to find possibility for applying high intensity laser to acupuncture and moxibustion treatment. Methods : Searching papers was performed using search engines of five electronic databases, including Pubmed, Thomson ISI, EMBASE, Sciencedirect, and EBSCO, from inception to May 2011 without language limitation. Inclusion criteria were clinical studies with human, randomized controlled trials (RCTs), case-control studies, and case reports. Selecting papers was performed with titles and abstracts in first step, scrutinize full text in second step, and then the extrated data was analyzed by two authors independently. The methodological quality for RCTs was evaluated using Jadad's scale. Results : Total 8 papers, (3 RCTs, 5 controlld studies, and 1 case reports), were finally selected. The study dealt with surgical laser, argon and $CO_2$ laser was one for each, with GaAs laser was two, and with new semiconductor laser, GaN, were four. The output range was from 110 mW to 15 W. The study diseases were alcohol addiction, knee osteoarthritis, bronchopneumonia and asthma for children, and circulation. All studies reported positive effect. The methodological quality in all RCTs was low because of below 3 points and all studies had few subject numbers. Conclusions : We suggest that high intensity laser can be applied to acupuncture and moxibustion. Further rigorous and well-designed study will be needed for various disease. The oriental medical society needs to take active measures to study and clinical application of acupuncture and moxibustion treatment with high intensity laser.

International and Asian Networks on Intense Laser Science

  • Kato, Yoshiaki
    • Journal of the Optical Society of Korea
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    • v.13 no.1
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    • pp.2-7
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    • 2009
  • This paper reviews evolution of the research networks on intense laser science under international and Asian frameworks during 2000 to 2008. The OECD Global Science Forum Steering Committee on Compact, High-Intensity Short-Pulse Lasers led to the establishment of the International Union of Pure and Applied Physics (IUPAP) Working Group: International Committee on Ultrahigh Intensity Lasers (ICUIL) and the Asian Intense Laser Network (AILN) in 2004. Through various activities under AILN such as the Asian Symposium on Intense Laser Science (ASILS), the Asian Summer School on Laser Plasma Acceleration and Radiation, and the High-Order Harmonics Workshops, closer relations are being formed among the scientists and also among the young generations working in intense laser science in the Asian regions.

The Effects of High Intensity Laser Therapy on Pain and Function of Patients with Frozen Shoulder

  • Jeon, Chun-Bae;Choi, Seok-Joo;Oh, Hyun-Ju;Jeong, Mu-Geun;Lee, Kwan-Sub
    • The Journal of Korean Physical Therapy
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    • v.29 no.4
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    • pp.207-210
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    • 2017
  • Purpose: This study was to identify the effectiveness of high-intensity laser therapy on pain and function of a frozen shoulder. Methods: Thirty patients were assigned to two groups: the experimental group (n=15) and the control group (n=15). Both groups received traditional therapy for 4 weeks, 3 days a week. The experimental group, however, received an additional high intensity laser therapy. Pain was measured using the visual analogue scale (VAS). The functional ability was measured using the patient specific functional scale (PSFS). A paired t-test was used to determine any differences before and after the treatment, and an independent t-test was used to determine any differences between treatment groups. Results: Both groups showed a statistically significant difference for VAS and PSFS score (p<0.05). In comparison between two groups, more experimental group than control group statistically significant difference (p<0.05). Conclusion: There seems to be a positive effect on pain and function of frozen shoulder from using high intensity laser therapy.

Novel Design of Ultrashort Pulse Excimer Laser Amplifier System I (Energy Characteristics)

  • Lee, Young-Woo
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.39-43
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    • 2003
  • The technology required to advance the state of the art of ultra-high-intensity excimer amplifier construction to the 100 J/100fs output pulse level is identified. The preliminary design work for very large final amplifier pumped by electron beam module is described, and key design problems and approaches are presented and discussed in detail based on the recent experimental and theoretical results.

Control of Intensity Distribution Profile of Laser Beam using Beam Shaping Mask with Random Array Slits (빔셰이퍼 마스크를 이용한 레이저 빔의 강도 분포 제어)

  • Oh, Jae-Yong;Park, Deog-Su;Shin, Bo-Sung
    • Laser Solutions
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    • v.15 no.2
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    • pp.11-14
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    • 2012
  • In this paper, we have made a proposal concerning the beam shaping mask(BSM) using random-array slits to control intensity distribution profile of laser beam and demonstrated its proprieties experimentally. When a lot of slits are set out irregularly, diffraction patterns of light does not appear but granularity patterns as a bundle of fibers appear. Intensity distribution profile is controlled by densities distribution of circular slits arrayed randomly because the number of slits and its area means amount of light energy through BSM. Namely as the number of slits in high intensity area is increased and that in low intensity area decreased, amount of light energy is same over all local parts. So gaussian intensity distribution could be changed to flat-top.

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Development of Real-time Monitoring System for Muscle Tension by High Intensity Laser Therapy (고출력 레이저 치료를 통한 근강직 완화의 실시간 모니터링 연구)

  • Hong, Jungsun;Youn, Jong-In
    • Journal of Biomedical Engineering Research
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    • v.33 no.3
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    • pp.128-134
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    • 2012
  • Currently, high-intensity laser therapy (HILT) is increasingly used in various muscle disorders like muscle tension. Our proposed study includes the development of the real-time monitoring system using a myotonometer for HILT. The developed system consists of a piezoelectric sensor and laser distance sensor for muscle stiffness monitoring during the treatments. The results demonstrated that the level of muscle tension was rapidly decreased after 3 minutes of the high-intensity laser treatment when compared to the control group. The combined HILT and realtime muscle tension monitoring system may help to evaluate the therapeutic procedure and efficient treatments for various muscle pains.

Evaluation of Muscle Tension in Hemiplegia Patients with a Real-time Monitoring System during High Intensity Laser Therapy

  • Lee, Sang-Kwan;Lee, Hyeong-O;Youn, Jong-In
    • Journal of the Optical Society of Korea
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    • v.19 no.3
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    • pp.277-283
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    • 2015
  • In this study, we evaluated the muscle tension in hemiplegia patients using a real-time monitoring system combined with high-intensity laser treatment (HILT) device. Five hemiplegia patients were treated with HILT in the left forearm muscle for 8 minutes, and the muscle was relaxed for 8 minutes following the treatment. Both the gradient of the force-displacement curves and the muscle hardness decreased during the therapy, and the effects were maintained following the treatment. The results show that muscle tension decreased rapidly during laser irradiation, and the efficacy of the treatment depended on the duration of the illness. Consequently, we conclude that this combined HILT and real-time muscle tension monitoring system is useful for evaluating the therapeutic procedure and for treatment of muscle pain.

Ultralow Intensity Noise Pulse Train from an All-fiber Nonlinear Amplifying Loop Mirror-based Femtosecond Laser

  • Dohyeon Kwon;Dohyun Kim
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.708-713
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    • 2023
  • A robust all-fiber nonlinear amplifying loop-mirror-based mode-locked femtosecond laser is demonstrated. Power-dependent nonlinear phase shift in a Sagnac loop enables stable and power-efficient mode-locking working as an artificial saturable absorber. The pump power is adjusted to achieve the lowest intensity noise for stable long-term operation. The minimum pump power for mode-locking is 180 mW, and the optimal pump power is 300 mW. The lowest integrated root-mean-square relative intensity noise of a free-running mode-locked laser is 0.009% [integration bandwidth: 1 Hz-10 MHz]. The long-term repetition-rate instability of a free-running mode-locked laser is 10-7 over 1,000 s averaging time. The repetition-rate phase noise scaled at 10-GHz carrier is -122 dBc/Hz at 10 kHz Fourier frequency. The demonstrated method can be applied as a seed source in high-precision real-time mid-infrared molecular spectroscopy.

Study on the characteristics of the plasma induced by lap-joint $CO_2$ laser welding of automotive steel sheets (자동차용 강판의 겹치기 $CO_2$ 레이저 용접에서 발생되는 플라즈마 특성에 관한 연구)

  • 남기중;박기영;이경돈
    • Laser Solutions
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    • v.5 no.1
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    • pp.33-42
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    • 2002
  • In order to investigate the characteristics of the plasma induced by lap-joint CO$_2$ laser welding of automotive steel sheets, the effects of welding speed, shield gas flow rate, gap size, and laser beam defocus to plasma intensity emitted from keyhole have been investigated. The plasma light is measured by fiber and photodiode. Also, the plasma images were captured by the high speed digital camera in 1000frames/sec in order to correlate the plasma light signal with plasma pattern. From the results, it is observed that the difference of the plasma intensity for between the deep penetration and partial penetration exists from 1.2 to 2 times. The plasma light intensity decreased in case of the deep penetration Is observed due to the exhausting of the plasma gas under the sheet. On the other hand, under the conditions of the deep penetration, the plasma intensity is significantly increased by controling the conditions decreasing the penetration depth. It was specially founded that the effect of 0.3mm gap size at partial penetration condition is approximately similar to deep penetration in 0mm gap. It is concluded that the plasma intensity is able to evaluate the penetration depth in lap-joint welding and appears to offer the most straightforward correlation to the welding process.

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Characteristics of Injection-Locked High Power Diode Laser (고출력 다이오드 레이저의 주입-잠금 과정 연구)

  • 문한섭;김중복;이호성;양성훈;김점술
    • Korean Journal of Optics and Photonics
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    • v.6 no.3
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    • pp.222-227
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    • 1995
  • A single mode, 100-mW diode laser was injection-locked by the master laser which was spectrally narrowed with Littman-type grating feedback. In the incomplete-injection-locking, we observed that two frequencies were simultaneously generated from the slave laser. The power ratio and frequency shift of two frequency components were proportional to the square of injected laser intensity. When the ratio of the injection intensity to the slave laser intensity was about $10^{-3}$, the injection-locking bandwidth was to be about 1.4 GHz. The bandwidth proportionally increased to the square root of the injection intensity, which was in good agreement with the theoretical predictions. The Iinewidth of the locked-laser was about 2.5 MHz, which was five times as narrow as that of free-running operation. ation.

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