• Korean Journal of Acupuncture
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• v.31 no.4
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• pp.195-207
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• 2014

Objectives : The purpose of this study is to examine the effects of laser acupuncture according to the wavelength(532 nm, 650 nm, 830 nm, 904 nm, and 1064 nm) at the acupoint of GB34 GB39 on neuropathic pain rat induced by tibial and sural nerve transection(TST). Methods : Neuropathic pain in rats was induced by tibial nerve and sural nerve transection. The rats were divided into the intact group, the TST control group, and the laser acupuncture therapy group. The laser acupuncture therapy groups were then divided into subgroups with 532 nm(L532), 650 nm(L650), 830 nm(L830), 904 nm(L904), and 1064 nm(L1064) laser acupuncture therapy. The acupoint of GB34 GB39 was selected, and laser acupuncture therapy was provided on both sides alternatively twice a week in a total of 6 sessions. Results : All the laser acupuncture groups showed a significant decrease in reaction time and force intensity. L532, L904, and L1064 groups showed a significant decrease in Bax, the L532 group showed a significant increase in Bcl-2, L532 and L1064 groups showed a significant decrease in the Bax/Bcl-2 ratio, and L532 and L650 groups showed a significant increase in mGluR5, as compared with the TST control group, among nerve tissue reaction. Conclusions : These results showed that laser acupuncture therapy at each of the wavelengths had some significance on neuropathic pain.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.4 s.19
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• pp.91-99
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• 2004

Laser materials for eyesafe wavelength generation and Q-switching crystals for short pulse operation were studied and compared with each other. Er,Yb:phosphate glass as a laser material and $Co^{2+}:MgA1_2O_4$ as a saturable absorber were found to be an effective pair for a compact, light-weight passively Q-switched eyesafe laser operation. Simplified rate equation was used to estimate pulse parameters of the diode-pumped passively Q-switched laser.

• Journal of the Korean Society of Combustion
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• v.11 no.3
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• pp.26-35
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• 2006

This work forcus on the development of gas sensor that measure the concentrations of exhaust gas using diode laser, Each diode laser for exhaust gas measurement is set to work at near-IR using both DA and WMS methods. Also use of fiber-coupled optical elements makes such a sensor rugged and easy to align. The results showed that gas concentrations of $O_2$, CO, $CO_2$, NO are accurately measured within ${\pm}2%$ error. The application of WMS method increased the beam intensity 2-3 times higher than DA method. It were experimentally compared WMS (Wavelength Modulation Spectroscopy) with DA (Direct Absorption) for the accuracy.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.1
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• pp.38-44
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• 1984

Subnanosecond optical pulses with 0.8-1.Bum wavelength are generated by experimentally realizing a single pass fiber Raman laser. This fiber Raman laser is pumped by a mode-locked and Q-switched Nd-YAG laser. Two wave sum frequency phenomenon is also obsenred in the course of the experimental work. The fiber Raman laser is then used to measure dispersion characteristics of a sin\ulcorner mode fiber in the long-wavelength lesion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.3
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• pp.246-250
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• 2001

ZnO thin films for light emission device have been deposited on sapphire and silicon substrates by pulsed laser deposition technique(PLD). A Nd:YAG laser was used with the wavelength of355 nm. In order to investigate the emission properties of ZnO thin films, Pl measurements with an Ar ion laser a light source using an excitation wavelength of 351 nm and a power of 100 mW are used. All spectra were taken at room temperature by using a grating spectrometer and a photomultiplier detector. ZnO exhibited Pl bands centers around 390, 510 and 640 nm, labeled near ultra-violet(UV), green and orange bands. Structural properties of ZnO thin films are analyzed with X-ray diffraction(XRD).

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.409-410
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• 2008

We have demonstrated a tunable Raman fiber laser using the combination of broadband CFBG and tunable fiber Bragg grating with the center wavelength 1415nm, which is tuned by adjusting longitudinal strain in the wavelength range from 1410 to 1420nm. A total output power of the tunable laser was about 0.9W with 13.8% of laser slope efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.539-542
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• 2000

ZnO thin films for light emission device have been deposited on sapphire and silicon substrates by pulsed laser deposition technique(PLD). A Nd:YAG laser was used with the wavelength of 355 nm. In order to investigate the emission properties of ZnO thin films, PL measurements with an Ar ion laser as a light source using an excitation wavelength of 351 nm and a power of 100 mW are used. All spectra were taken at room temperature by using a grating spectrometer and a photomultiplier detector. ZnO exhibited PL bands centered around 390, 510 and 640 nm, labeled near ultra-violet (UV), green and orange bands. Structural properties of ZnO thin films are analized with X-ray diffraction (XRD).

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.6
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• pp.260-264
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• 2002

We developed LD Pumped Nd:$VVO_4$ microchip laser with the cavity length of 1mm. The microchip laser output was 87.5㎽ at the wavelength of 1063.9nm with the input power of 241㎽ at the wavelength of 809nm. The slope efficiency was 40.7% and the threshold input power was 31.1㎽. We have also defined input power limit for the single longitudinal mode operation theoretically. It was 2.5 times larger than that of threshold input intensity. According to the results of simulation, the Nd:YVO$_4$ microchip laser can be operated with the maximum output of 15㎽ for the single longitudinal mode up to the input power of 77.75㎽.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1428-1429
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• 2006

We investigated the diffraction efficiency, erasing property and rewriting property of diffraction grating with each wavelength of recording beam. A (P:P) polarized light was exposed on AsGeSeS and Ag/AsGeSeS thin film to form a diffraction grating by HeNe(635nm) laser and DPSS(532nm) laser. At the maximum efficiency condition, unpolarized HeNe laser beam was irradiated to erase 1ha generated diffraction grating. The HeNe laser showed more higher diffraction efficiency and the DPSS laser showed more faster diffraction grating time. At erasing and rewriting process, AsGeSeS(61%-85%)thin film showed better property than Ag doped Ag/AsGeSeS(53%-63%) double layer structured thin film.

• The Journal of the Korean dental association
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• v.56 no.7
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• pp.385-390
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• 2018

Laser means "Light amplification by stimulated emission of radiation". Laser have unique characteristics according to wavelength. Wavelenth of Waterlase is 2780nm and it can be absorbed to water and hydroxyapatite. When laser is applied to some material, its temperature goes up due to laser's energy. But in dental treatment high temperature is not good for teeth. High temperature can make dental pulp and bone necrosis. Waterlase can be absorbed to water droplet, so when it burst, it can cut soft and hard tissue without raising temperature. so it is so proper to dental treatment.