• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1072-1075
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• 2001

$Al_2O_3$ ceramics are generally used as components in processing equipment, devices or machinery because it can perform some functions better than competing metals or polymers. Many of these applications rely on $Al_2O_3$ ceramics special electromagnetic properties, its relative chemical inertness, hardness, strength and its temperature capabilities. But $Al_2O_3$ ceramics are brittle materials, a fact that may cause problems and at the same time be helpful while machining with laser. This study described a basic study of the input parameters effect on the dimension of the microhole at the $Al_2O_3$ ceramics using Excimer laser. In the laser microhole machining of $Al_2O_3$ ceramics, major input parameters are pulse energy, pulse power, pulse frequency and pulse numbers. In conclusion, we can get a smaller microhole and diameter rate by an appropriate pulse energy, pulse frequency and pulse number.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.630-633
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• 2003

Integrating the driver circuitry directly onto the glass substrate would be one of the advantages of polycrystalline Si (poly-Si) TFT-(LCD). Low-temperature poly-Si TFT(LTPS) is well-suited for higher-definition display applications due to its intrinsically superior electrical characteristics. In order to improve LTPS electrical characteristics, currently the excimer laser-induced crystallization (ELC) processes and sequential lateral solidification method were developed. Grain size of the poly-Si is mainly affected by beam pitch and energy density. Key parameter for making a larger poly-Si using excimer laser annealing(ELA) and increasing a throughput is due to increase in beam pitch and energy density to a certain degree. Furthermore, thin $SiO_{2}$ capping is effective to suppress the protrusion of the poly-Si thin films and to reduce the interface state density. From the ELA process, we are able to control grain size by varying different parameters such as number of shots and energy density.

• 한국자동차공학회논문집
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• 제2권4호
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• pp.91-99
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• 1994

Tunable KrF Excimer Laser is used here for measuring OH and $O_2$ density distribustion in an open $H_2$/air premixed flame and in a combustion bomb. Laser Rayleigh Scattering(LRS) and Planar Laser Induced Predissociative Fluorescence(PLIPF) methods are used to obtain two-dimensional images of total and specific densities. Laser Excitation wavelengths are calibrated via flame images and combustion bomb images show good qualitative a greement with theoretical calculation. Furthermore images in a combustion bomb can be developed to study real Spark-Ignition engine combustions. Our experimental images show that there are no more collisional quenching problem at high pressure environment(including atmospheric pressure) using predissociative fluorescence technique. Further development to obtain two-dimensional temperature dustribution is ready to use eventhough it is not reported in this paper.

• 한국레이저가공학회지
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• 제8권2호
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• pp.21-32
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• 2005

The excimer laser ablation of a polymer occurs by the excitation of chemical bonds to energy levels that are above the dissociation energy. In this process, however, fragmented debris is finally ejected explosively by the scission of bonds and accumulates on the material surface. In the present work, a process for eliminating surface debris contamination generated by the laser ablation of a polymer is developed. The proposed approach for removing surface debris utilizes an erasable ink pasted on a polymide. The ink pasted polyimide is ablated by KrF excimer laser. The surface debris ejected from the polyimide is then combined with the ink layer on the polymer. Finally, both the surface debris and the ink layer are removed using adhesive tape or alcohol solvent. The results suggest that the erasable ink method is a simple, low cost, and extremely effective debris eliminating process.

• Journal of Yeungnam Medical Science
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• 제17권1호
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• pp.55-65
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• 2000

VISX 엑시머레이저 굴절교정각막절제술의 경우 근시는 다영역 단연마법(Multi-zone, Single pass Ablation)으로, 근시성난시는 타원형 방식(Elliptical mode)에 의해 교정하는 원리를 채택하고 있다. VISX 20/20B $VisionKey^{TM}$ 엑시머레이저의 version 4.01 software를 이용하여 시술한 근시교정술(PRK)과 근시성난시교정술(PARK)의 임상성적에 차이가 있는지 알아보고자 하였다. 1995년 3월부터 1996년 12월까지 엑시머레이저 굴절교정각막절제술을 시행하고 술후 1년까지 경과관찰이 가능했던 PRK 152안, PARK 203안을 대상으로 후향적 연구를 시행하였다. 나안시력, 교정시력, 굴절력, 안압, 각막 혼탁, 각막지형도 등을 술후 1, 3, 6 및 12개월에 검사하였으며, 모든 환자는 12개월 이상 경과 관찰하였다. 술후 1년에 나안시력이 0.7 이상인 경우가 -7D 미만의 PRK군(110안)에서 94.8%, PARK군(104안)에서 88.1%이었고, -7D 이상의 PRK군(31안)에서 86.1%, PARK군(57안)에서 67.1%이었다. 예측도가 ${\pm}1D$ 이내인 경우가 PRK 및 PARK에 따라 -7D 미만에서 97.4%, 93,2%이었고, -7D이상에서는 각각 80.6%, 70.6%이었다. 본 연구에서 종전의 보고된 연구 결과들에 비해 나안시력 개선 및 예측도 등에서 상대적으로 우수한 성적을 나타내었음을 알 수 있었다. 대부분의 근시와 근시성난시는 VISX 20/20B $VisionKey^{TM}$ 엑시머레이저를 이용하여 효과적으로 치료할 수 있었고 PARK에서도 PRK와 유사한 정도의 우수한 성적을 얻었으나, PRK에 비해 보다 정확한 중심잡기와 축정렬 등의 중의가 요망된다. 향후 멕시머레이저와 소프트웨어의 발전에 의해 두 군 모두에서 성적향상을 기대할 수 있으리라 생각된다.

• 광학세계
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• 제6권6호통권34호
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• pp.61-70
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• 1994

• 한국광과학회:학술대회논문집
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• 한국광과학회 1999년도 학술대회지
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• pp.91-91
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• 1999

• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제14회 학술발표회 논문개요집
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• pp.188-188
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• 1998

• 한국광학회:학술대회논문집
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• 한국광학회 1996년도 Advance Program of 13th optics andquantum Electronics conference, 1996제13 회 광학 및 양자전자 학술 발표회 논문 요약집
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• pp.34-34
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• 1996

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.993-996
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• 2012

We investigated fluorescence and fluorescence excitation of diphenylsilane (DPS) in a solution and molecular beams in combination with the aid of the DFT method. When the molecule was photoexcited at 250 nm in a cyclohexane solution, normal and excimer fluorescences were observed in the ranges of 260-320 and 330-450 nm, respectively. The fluorescence excitation spectrum indicates that the channel leading to the intramolecular excimer formation is not efficient in comparison with the normal fluorescence. Vibrationally resolved fluorescence excitation spectra were measured for the DPS molecules cooled in pulsed supersonic expansion of He in the range 262.2-271.7 nm, in which we can see several electronic excitation spectra exhibiting the electronic band origins. We found that the simulated absorption spectrum based on the time-dependent densityfunctional theory calculations accords well with the absorption spectrum.