• Title/Summary/Keyword: laser application

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The excimer laser ablation of PET for nickel electroforming (니켈 전주도금을 위한 PET의 엑시머 레이저 어블레이션)

  • Shin, Dong-Sik;Lee, Je-Hoon;Seo, Jung;Kim, Do-Hoon
    • Laser Solutions
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    • v.6 no.2
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    • pp.35-41
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    • 2003
  • In this study, manufacturing of polymer master and mold insert for micro injection molding was investigated. Ablation by excimer laser radiation could be used successfully to make 3-D microstructure of PET. The mechanism for ablative decomposition of PET with KrF excimer laser(λ: 248nm, pulse duration: 5ns) was explained by photochemical process. And this process showed PET to be adopted in polymer master for nickel mold insert. Nickel electroforming by using laser ablated PET master was preferable for replication method. Finally, it was shown that excimer laser ablation can substitute for X-ray lithography of LIGA process in microstructuring.

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An Analysis of the Correlation between He-Ne Laser Therapy in Literature and Clinical Application (He-Ne 레이저에 대한 문헌과 이를 근거로 한 임상 활용 예의 비교 고찰)

  • Youn, In-Hwan;Kim, Nam-Kwen
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.19 no.2
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    • pp.192-201
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    • 2006
  • Objectives : Recently, He-Ne laser has been used for clinical purpose. We study the medical basis of He-Ne laser therapy and We make a proposal concerning the clinical application of using He-Ne laser in Medicine. Methods : We have selected data related to He-Ne laser therapy and study how to use He-Ne laser in clinic. Results : In biology, He-Ne laser therapy has been effects of an improve in skin regeneration an improve in peripheral and central nerve regeneration an improve in muscle regeneration, an anti-inflammation an alleviation of pain and a bone repair. In oriental medicine, He-Ne laser has been used to laser acupuncture and laser oriental physical treatment. In clinic, He-Ne laser have been used to care several parts like as facial palsy, facial spasm, trigeminal neuropathy, rhinitis and tinnitus. Recently, there is argument that He-Ne laser therapy is suitable to medical insurance. Conclusions : Laser therapy in oriental medicine is widespread and We can apply He-Ne laser to facial palsy, facial spasm, trigeminal neuropathy, rhinitis, tinnitus by using laser acupuncture or laser oriental physical treatment. Till now the whole mechanisms are not fully understood, so we hope to study these mechanisms actively and make suitable to medical insurance device in the near future.

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Use of 1,064-nm Q-switched Neodymium:Yttrium-aluminum-garnet Laser Therapy Assisted with Diamond Particle Suspension and Gold Microparticle Application for Acne Vulgaris and Enlarged Facial Pores

  • Park, Hee Ung;Cho, Hangrae;Lee, Sang Ju;Cho, Han Kyoung
    • Medical Lasers
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    • v.10 no.4
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    • pp.242-245
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    • 2021
  • Acne vulgaris is a common inflammatory skin disease of the pilose-baceous unit. It appears as lesions consisting of comedones, papules, pustules, and nodules of varying shapes and severity. In general, the first-line treatment for acne vulgaris includes topical and oral medication. Recently, various physical modalities have also been investigated. The use of laser therapy is steadily increasing because of its fewer side effects, short procedure time, and rapid results. In particular, laser therapy assisted with carbon suspension application is effective for acne vulgaris but may sometimes result in discomfort due to odor and dust formation during the procedure. Herein, we report that acne vulgaris and enlarged facial pores can be safely and effectively treated with laser therapy assisted with diamond particle suspension and gold microparticle application, which can address the discomfort caused by the carbon suspension application.

Solidification Cracking Behavior in Austenitic Stainless Steel Laser Welds (Part 1) - Evaluation of Solidification Cracking Susceptibility by Laser Beam Welding Varestraint Test - (오스테나이트계 스테인리스강 레이저 용접부의 응고균열 거동 (Part 1) - 레이저 용접용 Varestraint 시험 시스템을 이용한 응고균열 민감도 평가 -)

  • Chun, Eun-Joon;Lee, Su-Jin;Suh, Jeong;Kang, Namhyun;Saida, Kazuyoshi
    • Journal of Welding and Joining
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    • v.34 no.5
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    • pp.54-60
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    • 2016
  • In order to quantitatively evaluate the solidification cracking susceptibility in laser welds of three types of austenitic stainless steels (type 310: A mode, type 316-A: AF mode, type 316-B: FA mode solidifications), the laser beam welding (LBW) transverse-Varestraint tests consisted of multi-mode fiber laser, welding robot and hydraulic pressure system were performed. As the welding speed increased from 1.67 to 40.0 mm/s, the solidification brittle temperature range (BTR) of laser welds for type 316 stainless steels enlarged (316-A: from 37 to 46 K, 316-B: from 14 to 40 K), while the BTR for type 310 stainless steel reduced from 146 to 120 K. In other words, it founds that solidification cracking susceptibility could not be simply mitigated through application of LBW process, and the BTR variation behavior is quite different upon solidification mode of austenitic stainless steels.

Laser Strengthening of $35kgf/\textrm{mm}^2$ Grade Steel Sheet far Automobile (자동차용 $35kgf/\textrm{mm}^2$급 강판의 레이저 강화)

  • Suh, Jeong;Lee, Jae-Hoon;Kim, Jeong-O;Oh, Sang-Jin;Cho, Won-Suk;Lee, Doo-Hwan;Shin, Chirl-Soo;Lee, Moon-Yong;Lee, Gyu-Hyun
    • Journal of Welding and Joining
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    • v.20 no.1
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    • pp.34-40
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    • 2002
  • The laser strengthening of $35kgf/\textrm{mm}^2$ grade steel sheet is investigated by using $CO_2$ laser beam irradiation. The increase of tensile strength is dominated by the number of fully penetrated melting lines. Also, the optimal laser irradiation pattern is obtained by 3-point bending test. Local laser strengthening clay be effective for the weight reduction of automobile components where the tailored welded blank can not be applied.

Experimental Investigation of a High-repetition-rate Pr3+:YLF Laser with Single-frequency Oscillation

  • Dai, Weicheng;Jin, Long;Dong, Yuan;Jin, Guangyong
    • Current Optics and Photonics
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    • v.5 no.6
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    • pp.721-729
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    • 2021
  • We demonstrate a Pr3+:YLF 639.7-nm laser with single-frequency output based on the Q-switched pre-lase technology, pumped by a fiber-coupled GaN blue laser diode. The pre-lase technology is realized by the step-type loss of the acousto-optical Q-switched device. The conclusions of the theoretical research are verified experimentally. The mode-suppression ratio was 44 dB at the single-frequency laser output. Detection by interferometer verified the realization of the stable single-frequency laser. In addition, the emission spectrum had a linewidth of 139.9 MHz, measured by Fabry-Perot interferometer. The single-frequency laser's single-peak power was over 19.7 W with 98.8-ns pulse duration, obtained under an absorption power of 1.74 W.

Laser micromachining of micron-size aperture for electron beam microcolumn application using the piezo-switched Nd:YAG laser (Piezo Q-Switched Nd:YAG 레이저에 의한 초미니 전자빔 장치용 Micron-Size Aperture의 레이저 미세가공)

  • 안승준;김대욱;김호섭;최성수
    • Journal of the Korean Vacuum Society
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    • v.8 no.4A
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    • pp.456-460
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    • 1999
  • Experimental studies of laser micromachining on Mo diaphragm using piezo Q-switched Nd:YAZ laser have been performed. Application of miniaturized micorcolumn electron gun arrays as a potential electron beam lithography or portable mini-scanning electron microscope (SEM) application have recently extensively examined. The conventional microcolumn fabrication technique would give a limitation on the minimization of aberration, In this paper, we obtained 20~30 $\mu \textrm m$aperture of laser micromachining on Mo diaphragm using piezo Q-swithed Nd:YAG laser. The geometrical figures, such as the diameter and the preciseness of the drilled aperture are dependent upon the total energy of the laser pulse train, laser pulse width, and the diameter of laser spot in addition to the materials-dependent parameters.

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Study on the Formation Mechanism of Electroless Plating Seeds on Polymer by Laser (레이저에 의한 폴리머상의 무전해 도금 시드 형성 메커니즘 연구)

  • Paik, Byoung-Man;Lee, Jae Hoon;Shin, Dong-Sig;Lee, Kun-Sang
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.1
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    • pp.41-47
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    • 2012
  • The LDS(Laser Direct Structuring) is one of the new direct writing methods to fabricate conductive patterns by energy beam. It uses thermoplastic polymers with an additive compound that serves as plating seed after the activation by laser. The advantages of LDS include the miniaturization of electrical components, design flexibility, and a reduced number of production steps. The purpose of this study is to investigate the fundamental mechanism for LDS and the characteristics of conductive patterns by laser parameters. These results were studied by SEM, EDX, and XPS analysis. We have used a 20W pulse-modulated fiber laser and copper electroless plating to fabricate conductive patterns on polymer. The result showed that electroless copper plating seed caused the laser cracking of additive compound. In particular, the additive compound contained in copper metal oxides atoms will be changed to copper metal elements. Also, the characteristics of conductive patterns were dependent on laser parameter, especially laser fluence.

$CO_2$ Laser Irradiation Strengthening by Defocused Beam (비집속빔을 이용한 $CO_2$ 레이저 빔 조사강화)

  • Seo, Jung;Lee, Je-Hoon;Kang, Hee-Sin;Kim, Jung-Oh;Lee, Moon-Yong;Oh, Sang-Jin;Lee, Kyu-Hyun
    • Laser Solutions
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    • v.6 no.2
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    • pp.1-7
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    • 2003
  • Defocused CO$_2$ laser beam irradiation strengthening of 60kgf/$\textrm{mm}^2$ grade steel sheet was investigated to obtain the tensile strength similar to that of fully penetrated one by the focused beam. The melted line width by the defocused beam was 3∼4 times larger compared to that of the focused beam. However, the increase of tensile strength with 1 line irradiation by the defocused beam was similar to that of 2~3 lines by the focused beam. The increase(37.6%) of bending strength with 1 line by the defocused beam was higher than the increase(12.9%) of tensile strength. Also, the effect of cooling gas to strengthening was observed.

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Study on Printing Roll Manufacturing by using 3 Dimensional Laser Scanner (3차원 레이저 스캐너를 이용한 인쇄롤 가공에 관한 연구)

  • Kang, Heeshin;Noh, Jiwhan;Sohn, Hyonkee
    • Laser Solutions
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    • v.16 no.4
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    • pp.17-23
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    • 2013
  • The research for the development of roll-to-roll printing process is actively underway on behalf of the existing semiconductor process. The roll-to-roll printing system can make the electronic devices to low-cost mass production. This study is performed for developing the manufacturing technology of the printing roll used in the printing process of electronic devices. The indirect laser engraving technology is used to create printable roll and the printable roll is made out of the chrome coated roll after coating copper and polymer on the surface of steel roll, ablating the polymer on the surface of roll and etching the roll. The 3 dimensional laser scanner and roll rotating systems are constructed and the system control program is developed. We have used the fiber laser of 100 W grade, the 3 dimensional laser scanner and the 3 axes moving stage system with a rotating axis. We have found the optimal conditions by performing the laser patterning experiments and can make the minimum line width of $24{\mu}m$ by using the developed 3 dimensional laser scanner system.

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