• 제목/요약/키워드: Optical pumping

검색결과 154건 처리시간 0.023초

Development of Minimally Invasive Mid-infrared Lipolysis Laser System for Effective Fat Reduction

  • Lee, Ji-Young;Ryu, Han Young;Seo, Young-Seok
    • Medical Lasers
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    • 제10권2호
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    • pp.82-89
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    • 2021
  • Background and Objectives Due to changes in diet and lifestyle, the number of obese people worldwide is steadily increasing. Obesity has an adverse effect on a healthy life, so it needs treatment and improvement. Research related to this is continuously being conducted. Materials and Methods The laser system to compact designed using 808 nm laser diode and Neodymium Yttrium orthovanadate generates a 1064 nm wavelength, the periodically polarized nonlinear crystal pumping laser beam. The pulsed 1064 nm wavelength beam passing through the AO Q-switch is used as the pumping light of the nonlinear optical crystal and is irradiated to the periodic polarized nonlinear optical crystal with a quasi-phase matching period. Nonlinear optical crystals use an oven to control the temperature to generate the desired 1980 nm and 2300 nm wavelengths. Results The 1980 nm and 2300 nm wavelengths generated by temperature control of nonlinear optical crystals are effective for lipolysis. A fiber catheter was used so that the laser could be directly irradiated to the fat cells. In particular, the new wavelength (1980 nm, 2300 nm) can increase the fat reduction effect with low energy (1.3 W). When a laser with a combination wavelength of 1980 nm and 2300 nm was used, an average lipolysis effect of 20% was obtained. Conclusion A mid-infrared lipolysis laser system with excellent absorption of fat and water has been developed. We conducted a princlinical study to confirm the efficacy and safety of the lipolysis laser system, and obtained good results for lipolysis with low energy.

TIME VARIATION OF SiO (v=1, J=2-1) MASERS OF LONG PERIOD VARIABLES

  • LEE SANG GAK;KIM EUNHYEUK;LEE HYUNG MOK
    • Journal of The Korean Astronomical Society
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    • 제27권2호
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    • pp.133-146
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    • 1994
  • We have detected a SiO maser line (v=1, J=2- 1) for 15 stars out of about 80 long period variables in the wide range of period. No new sources are detected; all detected sources are variables with period longer than 300 days; no evidence is found that the dust grains in the outer envelope have influenced on this line. The time variation of this maser line for 7 stars, T Cep, ${\mu} Cep$, U Her, R Leo, R Lmi, U Ori, and R Ser is observed and compared with optical light curve at the same epoch of maser observation. No universial relation between the time variation and the optical light curve is found. It implies that the radiation from a central star does not much play an important role for the direct pumping of the SiO maser line.

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A Study on Pumping Effect of Oxygen in Polysilicon Gate Etching

  • Kim, Nam-Hoon;Shin, Sung-Wook;Bin, Shin-Seok;Yu chang-Il kim;Chang, Eui-Goo
    • Transactions on Electrical and Electronic Materials
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    • 제1권2호
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    • pp.1-6
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    • 2000
  • This article presents the experiments and considerations possible about gate etching in polysilicon when oxygen gas is added in chamber, We propose the novel study with optical emission spectroscopy in polysilicon etching. It is shown that added oxygen gases play an important role in enhencement of density in chlorine gases as a scavenger of silicon from SiCl$\_$x/. And a small amount of Si-O bonds are deposited and then the deposited thin film protect silicon dioxyde against reaction chlorine with silicon in SiO$_2$. Consequently, we can improve the selectivity of polysilicon the silicon dioxide, which is clearly explained in this model.

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Characteristics of Optical Phase Conjugate Wave Generated by Self-Pumping in Photorefractive $BaTiO_3$ Single Crystal ($BaTiO_3$ 광굴절 결정에서 자기 펌핑에 의해 발생되는 위상공액파의 특성)

  • 이장두
    • Proceedings of the Optical Society of Korea Conference
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    • 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
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    • pp.157-161
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    • 1990
  • Self-pumped phase conjugation(SPPC) in BaTiO3 single crystal is experimentally investigated at a wavelength of 514.5nm from an Ar+ laser. The incident Gaussian beam enters the crystal as an extraordinary ray. The maximum SPPC reflectivity of 48% is obtained at incident angle 80 degree. the SPPC wave demonstrates good image reconstruction. The response time (r) of SPPC wave as a function of incident intensity is measured to be r=36$\times$I-0.79sec.

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Measurement of isotopic shifts and hyperfine splittings for Yb in $^3p_1{\leftrightarrow}^3D_1$ transition by using velocity selective optical pumping spectroscopy (속도군선택광펌핑 분광을 이용한 이터븀 원자$^3p_1{\leftrightarrow}^3D_1$ 전이선에서의 동위원소 주파수 이동 및 초미세 구조의 측정)

  • Lee, Rim;Park, Hyeon-Min;Go, Gwang-Hun;Jeong, Do-Yeong
    • Proceedings of the Optical Society of Korea Conference
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    • 한국광학회 2009년도 창립 20주년기념 특별학술발표회
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    • pp.42-43
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    • 2009
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Construction and Study of Longitudinally Pumped single Mode Pulsed Dye Laser (종펌핑 단일 종모드 섹소레이저 제작 및 특성연구)

  • 이종훈
    • Proceedings of the Optical Society of Korea Conference
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    • 한국광학회 1989년도 제4회 파동 및 레이저 학술발표회 4th Conference on Waves and lasers 논문집 - 한국광학회
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    • pp.43-45
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    • 1989
  • Single mode pulsed incidence dye laser which has TEMoo spatial beam pattern, near gaussian temporal shape and narrow band width(less than 500MHz) has been constructed The improved performance comes as a results of cavity length(~5cm) and definition of optical path by means of longitudinal pumping. Using 1.0X10-4M RH-6G dye, conversion efficiency was approximately 2.2% and tuning range was 548-564nm.

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The Influence of Rapid Thermal Annealing Processed Metal-Semiconductor Contact on Plasmonic Waveguide Under Electrical Pumping

  • Lu, Yang;Zhang, Hui;Mei, Ting
    • Journal of the Optical Society of Korea
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    • 제20권1호
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    • pp.130-134
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    • 2016
  • The influence of Au/Ni-based contact formed on a lightly-doped (7.3×1017cm−3, Zn-doped) InGaAsP layer for electrical compensation of surface plasmon polariton (SPP) propagation under various rapid thermal annealing (RTA) conditions has been studied. The active control of SPP propagation is realized by electrically pumping the InGaAsP multiple quantum wells (MQWs) beneath the metal planar waveguide. The metal planar film acts as the electric contact layer and SPP waveguide, simultaneously. The RTA process can lower the metal-semiconductor electric contact resistance. Nevertheless, it inevitably increases the contact interface morphological roughness, which is detrimental to SPP propagation. Based on this dilemma, in this work we focus on studying the influence of RTA conditions on electrical control of SPPs. The experimental results indicate that there is obvious degradation of electrical pumping compensation for SPP propagation loss in the devices annealed at 400℃ compared to those with no annealing treatment. With increasing annealing duration time, more significant degradation of the active performance is observed even under sufficient current injection. When the annealing temperature is set at 400℃ and the duration time approaches 60s, the SPP propagation is nearly no longer supported as the waveguide surface morphology is severely changed. It seems that eutectic mixture stemming from the RTA process significantly increases the metal film roughness and interferes with the SPP signal propagation.