• 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.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.12
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• pp.894-898
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• 2013

Zinc oxide(ZnO) was sputtered on various glass and flexible substrates such as polyethylene terephthalate(PET) and polycarbonate(PC). A Q-switched $Nd:YVO_4$ laser with a wavelength of 1,064 nm was used for the direct etching of ZnO films. It was possible to obtain laser etched line patterns on the ZnO films on PC substrate at some specific laser beam conditions. In the flexible substrates, more thermal energy of laser beam is expected to be spreaded for the etching process.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.94-98
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• 2007

AC PDP에 사용되는 ITO 전극의 공정시간을 단축시키고 생산성을 향상시키기 위해서 $Nd:YVO_4$ laser(${\lambda}=1064\;nm$)를 사용하여 ITO 전극 패턴을 형성하였다. ITO etchant를 사용하여 ITO 전극 패턴을 형성한 샘플과 비교해서 laser를 사용하여 제작한 샘플은 ITO 라인 가장자리에 shoulder와 물결무늬를 형성했다. Q스위치 $Nd:YVO_4$ laser와 갈바노메트릭 스캐닝 시스템을 사용하여 500 mm/s의 스캔속도와 40 kHz의 펄스 반복 율을 기본조건으로 결정했다. PDP 테스트 샘플을 제작하여 방전 테스트를 진행하였다. 사진식각공정을 이용하여 만든 PDP 샘플과 비교해서 laser를 이용하여 제작한 PDP 샘플의 최소 방전유지전압은 더 높게 측정됐다. 이것은 ITO 라인의 shoulder와 물결무늬의 형성과 관련이 있다고 판단된다. 본 실험을 통해 레이저를 이용한 PDP용 ITO 전극막의 직접 패터닝 가능성을 확인할 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1335-1336
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• 2008

A compact diode-pumped microchip(DPM) green light source which consist of pump LD, $Nd:YVO_4$, KTP and a built-in thermoelectric element has been fabricated for laser projection display. The volume of the source is as small as $0.7\;cm^3$ and we obtained the output power of 25mW with the average electric power consumption in pump LD of 304mW which correspond to the electrical-to-optical efficiency of 7.8%. Another approach using quasi phase matching(QPM) technique has been attempted. We obtained the output power of 90mW of green beam with 350mW pumping of a $Nd:YVO_4$ laser with 20-kHz rep. rate and 10-ns pulse duration. Detailed characteristics and issues of the DPM and QPM green light sources will be addressed.

• Journal of the Optical Society of Korea
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• v.9 no.2
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• pp.64-67
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• 2005

A diode-pumped $Nd:YVO_4$ laser is developed. The laser has a closely folded resonator. The laser beam in two arms of the folded resonator passes the same acousto-optic modulator. The laser output power and pulsewidth dependence on a Q-switching frequency were measured. It is found that the newly proposed geometry provides an effective means for reducing the pulsewidth while maintaining almost the same output power compared with the usual folded resonator, where the beam in one arm of the resonator passes the acousto-optic modulator.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1496-1499
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• 2009

A diode-pumped Nd:$YVO_4$ laser was used to obtain indium tin oxide (ITO) patterns on glass substrate with various overlapping rates. The results showed that the overlapping rate of laser beam influences on the edge structure of ITO pattern and the surface roughness of ablated groove bottom. At a laser repetition rate of 40 kHz, the optimized condition of overlapping rate was 75 %.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.3
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• pp.146-150
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• 2014

As a method of simple patterning of transparent conductive oxide (TCO) films deposited on flexible substrates, laser direct etching was carried out on TCO films sputtered on polycarbonate (PC) substrates. As a result of different binding energies in TCO films, indium tin oxide (ITO) and indium gallium zinc oxide (IGZO) were more easily etched than zinc oxide with different $Nd:YVO_4$ laser beam conditions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.2
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• pp.133-136
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• 2010

Laser direct patterning is one of new methods which are able to replace a conventional photolithography. In order reduce the fabrication cost and to improve the luminous efficiency of AC plasma display panels (PDPs), in this experiment, a Q-switched Nd:$YVO_4$ laser was used to fabricate T-shaped indium tin oxide (ITO) display electrodes. For the laser beam scanning speed from 100 mm/sec to 800 mm/sec, T-shaped ITO patterns were clearly obtained and investigated. The experimental results showed that the optimized T-shaped ITO electrode was obtained when the lasers scanning speed was 300 mm/s.

• Korean Journal of Optics and Photonics
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• v.14 no.3
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• pp.292-297
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• 2003

A diode-pumped single-mode Nd:YV $O_4$ green laser was developed. Frequency doubling of the laser was achieved by using an intracavity KTP generated green beam (532 nm). By comparing the diode laser spectrum with absorption spectrum of the Nd:YV $O_4$ crystal, we found optimal operating temperature of the diode laser. From output power measured for various mirror curvatures and cavity lengths, we found the optimal matching of TE $M_{00}$ mode with the pump beam gives the best efficiency. When the pump power was 1.9 W, 80 ㎽ of TE $M_{00}$ mode green beam was obtained. We tried to get a single longitudinal mode lasing as the fluctuation of the laser power was caused by the shift of longitudinal modes and the beating between the modes. We tested the intracavity etalon method and birefringent filter method for single mode operation. The etalon method resulted in the best single mode output power of 60 ㎽. The power fluctuation of the single-mode laser was reduced to 1/10 of that of the multi-mode laser.

• Journal of Powder Materials
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• v.25 no.1
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• pp.12-18
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• 2018

Cost-effective functional phosphor nanoparticles are prepared by introducing low-cost $SiO_2$ spheres to rare-earth phosphor ($YVO_4:Eu^{3+}$, $YVO_4:Er^{3+}$, and $YVO_4:Nd^{3+}$) shells using a sol-gel synthetic method. These functional nanoparticles are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and general photoluminescence spectra. The $SiO_2$ sphere occupying the interior of the conventional phosphor is advantageous in significantly reducing the cost of expensive rare-earth phosphor nanoparticles. The sol-gel process facilitates the core-shell structure formation; the rare-earth shell phosphor has strong interactions with chelating agents on the surfaces of $SiO_2$ nanoparticles and thus forms layers of several nanometers in thickness. The photoluminescence wavelength is simply tuned by replacing the active materials of $Eu^{3+}$, $Er^{3+}$, and $Nd^{3+}$. Moreover, the photoluminescent properties of the core-shell nanoparticles can be optimized by manipulating the specific contents of active materials in the phosphors. Our simple approach substitutes low-cost $SiO_2$ for expensive rare-earth-based phosphor materials to realize cost-effective phosphor nanoparticles for various applications.