레이저를 이용한 3차원 공간 연출 조형에 관한 연구 -레이저아트를 중심으로-

조정호,김형기 한국일러스아트학회 2019 조형미디어학 Vol.22 No.3

Laser is a light made by humans that has an amazing characteristic that is not found in natural white light. Since it was first discovered in the 1960s, it has an infinite range of possibilities for applications based on user ideas, expresses formative forms and has a fantastic yet strong impact. The strong energy and intensity of laser are used in various forms, creating new technologies one after another and creating new industries. One of them is laser art. Because the pure color of lasers has a high degree of transparency and can make fantastic and vivid production, they can be combined with various IT technologies to make new laser art. One example is the laser-based media facade with intense effects. With the recent improvement in laser production technology, many small, high-powered lasers have been produced, and artists are producing kinetic art in combination with audio and visual. At this point, we are going to identify the characteristics of light art using laser as a technical part and visual art to find laser art as a better content production. As a research method, the characteristics of each type of laser used in media art are classified and the application method of laser art is studied accordingly. We propose a research and improvement method of the advantages and disadvantages of the technology according to the laser directing method by producing the media art using the laser. 레이저는 인간에 의해 만들어진 빛으로서 자연발생적으로 존재하는 백색광에는 없는 놀라운 특성을 갖는다. 레이저는 1960년대 처음 발견된 이후 사용자의 아이디어에 따라 응용 범위의 무한한 가능성을 갖고 있으며 조형적인 형태를 표출, 환상적이면서도 강한 Impact를 갖고 있다. 레이저가 가진 강한 에너지와 집광성은 다양한 형태로 이용되고 새로운 기술을 창조하고 산업 분야를 만들었다. 그중 하나로 레이저아트가 있다. 레이저의 순수한 빛깔은 투명도가 높고 환상적이며 생생한 연출을 할 수 있기 때문에 각종 IT 기술과 접목하여 새로운 레이저아트를 할 수 있다. 그 예의 하나로 레이저를 이용한 미디어파사드가 강렬한 효과로 연출되고 있다. 최근 레이저 생산 기술이 향상됨에 따라 소형 고출력 레이저들이 많이 생산되어 예술가들이 오디오ㆍ비주얼과 결합하여 키네틱 아트로도 제작되고 있다. 이 시점에서 레이저를 이용한 라이트아트의 특징을 기술적인 부분과 시각적 예술로서 특징을 규명하여 더 나은 콘텐츠 제작으로서의 레이저아트를 알아보고자 한다. 연구방법으로 미디어아트에 사용되어지는 레이저 종류별 특징을 분류하고 이에 따라 연출되는 레이저아트 적용방법을 연구하고자 한다. 레이저를 이용한 미디어아트를 제작하여 레이저 연출방식에 따른 기술의 장단점에 대한 연구 및 개선 방법을 제시하고자 한다.

Characteristics of Cutting Surface According to Cutting Direction and Laser Output During Laser-Oxygen Hybrid Cutting for Nuclear Power Plant Dismantling Application

DoYeong Mun,SunIl Kim,MinGyu Choi,DongHyun Kim,IlWoo Moon 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

Thermal cutting processes that can be applied to dismantling nuclear power plants include oxygen cutting, plasma cutting, and laser cutting. According to the global trend, research projects are being carried out in various countries to upgrade laser cutting, and many studies are also being conducted in Korea with plans to apply laser cutting processes when dismantling nuclear power plants. However, with the current technology level of the laser cutting process, the maximum thickness that can be cut is limited to 250 mm. Therefore, in this study, a laser-oxygen hybrid cutting process was implemented by adding a laser heat source to the oxygen cutting process that can cut carbon steel with a thickness of 250 mm or more (RV, beam, column, beam, etc.) when dismantling the nuclear power plant. This has the advantage of improving the cutting speed and reducing the cutting width Kerf compared to conventional oxygen cutting. In this research, the laser-oxygen hybrid cutting process consisted of laser cutting to which Raycus’ 8 kW Fiber Laser power source was applied and oxygen cutting to which hydrogen was applied with Fuel Gas. The oxygen torch was placed perpendicular to the test piece, and the laser head was irradiated by tilting 35° to 70°. The effects of cutting directions on quality and performance were studied, and cutting paths were selected by comparing cutting results. Thereafter, it was confirmed that there is an optimal laser output power according to the cutting thickness by studying the effect on the cutting surface quality by changing only the laser output power under the same cutting conditions. The results of this study are expected to be helpful in the remote cutting process using laser-oxygen hybrid cutting when dismantling domestic nuclear power plants in the future.

577 nm 레이저 섬유주성형술의 단기 임상효과

김종민,조경진,경성은,장무환,Jong Min Kim,MD,Kyong Jin Cho,MD,Sung Eun Kyung,MD,PhD,Moo Hwan Chang,MD,PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.4

Purpose: To evaluate the pressure-lowering effects of single-spot laser trabeculoplasty and patterned laser trabeculoplasty using a 577-nm wavelength laser. Methods: A total 35 eyes of 35 patients with primary open-angle glaucoma were enrolled in this study. Eighteen eyes of 18 patients were treated with 360° single-spot laser trabeculoplasty and 17 eyes of 17 patients were treated with 360° patterned laser trabeculoplasty. All patients were evaluated after laser trabeculoplasty at 1 week, 1 month, 3 months, and 6 months using slit lamp examination and Goldmann applanation tonometry. Results: At 6 months postoperatively, the single-spot laser trabeculoplasty group had a mean IOP of 15.89 ± 3.89 mm Hg with a mean IOP reduction of 37.1%, while the patterned laser trabeculoplasty group had a mean IOP of 17.57 ± 2.64 mm Hg with a mean IOP reduction of 27.1%. Conclusions: Laser trabeculoplasty with a 577-nm optically pumped semiconductor laser was safe and demonstrated an IOP lowering effect. There were no significant differences in the IOP lowering effects between the single-spot laser trabeculoplasty and the patterned laser trabeculoplasty. J Korean Ophthalmol Soc 2014;55(4):563-569

High power-pulsed Nd:YAG laser as a new stimulus to induce BMP-2 expression in MC3T3-E1 osteoblasts

Kim, In Sook,Cho, Tae Hyung,Kim, Kwansik,Weber, Franz E.,Hwang, Soon Jung Wiley Subscription Services, Inc., A Wiley Company 2010 Lasers in surgery and medicine Vol.42 No.6

<B>Background and Objective</B><P>High-power laser has recently become a physical stimulus for bone regeneration. Little is known about how high-power laser irradiation affects osteoblast differentiation. This study investigated osteoblast responses to high-power laser and combined irradiation with BMP-2 treatment.</P><B>Study Design/Materials and Methods</B><P>MC3T3-E1 pre-osteoblasts were exposed to laser irradiation, 100 ng/ml BMP-2 or both. Cells were irradiated with a Q-switched, pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a 1,064 nm wavelength and 0.75 W output power under 1.5, 3, or 5 J/cm<SUP>2</SUP> energy densities. Cell proliferation was evaluated using tetrazolium salt, WST-8. To determine the effect of these treatments on in vitro osteogenesis, we examined alkaline phosphatase (ALP) activity, mineral deposition, and expression of genes associated with osteogenesis. Quantitative real time PCR or ELISA was used to examine cytokine expression. In each experiment, either non-irradiated or BMP-2 (100 ng/ml)-treated cells were used as controls.</P><B>Results</B><P>High-power, low-level, Nd:YAG laser irradiation significantly increased ALP activity, when combined with BMP-2 or not. Cell proliferation declined in the irradiation and combined irradiation/BMP-2 groups. Interestingly, Nd:YAG laser stimulation resulted in significant induction of endogenous BMP-2 protein and gene expression. The increased expression of upstream regulators cbfa1 by Nd:YAG laser alone was comparable to exogenous BMP-2 treatment (100 ng/ml). Combined laser/BMP-2 treatment was synergistic in the expression of some genes (IGF-1, cbfa1) and ALP activity, compared to both BMP-2 treatment and laser irradiation alone. In vitro matrix mineralization was significantly accelerated by laser stimulation compared to that of the control, more so than with the combined laser/BMP-2 treatment.</P><B>Conclusions</B><P>The present in vitro findings demonstrate that high-power, low-level Nd:YAG laser increased osteoblast activity, very efficiently accelerating mineral deposition. Osteoinductive effect of laser is likely mediated by activation of BMP-2-related signaling pathway. Lasers Surg. Med. 42:510–518, 2010. © 2010 Wiley–Liss, Inc.</P>

레이저침 시술에 사용되는 레이저 기기의 적용 범위에 대한 고찰

황의형,양창섭,장인수 대한침구의학회 2009 대한침구의학회지 Vol.26 No.1

Objectives : During the past three decades there has been a significant evolution of laser acupuncture application in the nature of the clinical approach and the research of traditional medicine and laser therapy field. However, there have been no standard and guideline of laser equipment can be applied as laser acupuncture. This study aims to investigate the condition of laser equipment required as a laser acupuncture method. Methods : First, we performed literature search using the Medline (from 1999 to Oct 2008) to confirm types and ranges of laser equipments that can be applied as laser acupuncture. In addition, we investigated the characters of acupoints such as sites and depths, and compared with penetrating depths of each laser. Results : A total of 37 articles for clinical studies using laser acupuncture were selected, and 41 lasers were used. GaAs laser was used three times, GaAlAs laser 14, InGaAlP 18, HeNe laser 4, and Argon laser and CO2 laser were used one time, respectively. From all 361 points of fourteen meridians, depths of 341 points(94.5%) were 1 cun (2.3-3.2cm) or less. The mean depth of all points was 0.48 cun(1.1-1.5cm). Hence, it appeared that the majority of therapeutic lasers satisfied with the condition. HeNe, InGaAlP, GaAlAs, GaAs lasers are recommended for laser acupuncture, however, it may plausible that other surgical lasers could be used as the laser acupuncture, because it have the biostimulation effect to some extent, too. Conclusions : It is suggested that to select appropriate laser type and give the adequate output power to reach the acupoints under the skin using laser acupuncture. Further evaluation and research for the condition of laser acupuncture are warranted.

Digital selective laser methods for nanomaterials: From synthesis to processing

Hong, Sukjoon,Lee, Habeom,Yeo, Junyeob,Ko, Seung Hwan Elsevier 2016 Nano Today Vol.11 No.5

<P><B>Abstract</B></P> <P>Laser has long been used for material processing, and its applications to nanomaterials for their direct synthesis, positioning and processing are currently active fields of study. The main mechanism of typical laser processes is photothermal reaction by a focused laser that remotely generates confined temperature field at a desired position with high controllability. The laser-induced elevated temperature enables direct synthesis of nanomaterials in both gas and liquid environment as well as photophysical processing of nanomaterials through melting or vaporization, represented by laser sintering and ablation processes, in spatially selective manners. On the other hand, recent advances in laser process further incorporates not only different optical responses such as optical forces and photochemical reactions for more advanced manipulation of nanomaterials, but also the interaction between electromagnetic waves, nanostructures and underlying substrates to facilitate novel processing those cannot be achieved by any other means including laser nanowelding for percolation network and laser thinning for two dimensional nanomaterials. At the same time, the shortcomings of laser process in nanomaterial processing such as limited resolution and low throughput are tackled through introducing different optical schemes together with the integration with other systems. In this review, we summarize the development and current status of digital selective laser methods for nanomaterials in broad aspects that cover from nanomaterial synthesis to its processing.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Digital selective laser processes for nanomaterials are summarized in this review. </LI> <LI> Nanomaterials are selectively synthesized, positioned, controlled and manipulated. </LI> <LI> These processes rely on photothermal, photochemical or photothermochemical reaction. </LI> <LI> More emphasis is placed on the processes for nanoparticles, nanowires and nanosheets. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The Advent of Laser Therapies in Dermatology and Urology: Underlying Mechanisms, Recent Trends and Future Directions

이호,정연욱,Kin F. Chan 한국광학회 2009 Current Optics and Photonics Vol.13 No.3

Following their applications in cardiology, ophthalmology and dentistry among others, the advent of lasers in dermatology and urology had become the success story of the past decade. Laser-assisted treatments in dermatology and urology are mainly based on the laser-induced tissue injury/coagulation and/or ablation, depending upon the desirable clinical endpoint. In this review, we discussed the underlying mechanisms of the laser induced tissue ablation. In any medical laser application, the controlled thermal injury and coagulation, and the extent of ablation, if required, are critical. The laser thermal mechanism of injury is intricately related to the selective absorption of light and its exposure duration, similarly to the laser induced ablation. The laser ablation mechanisms were categorized into four different categories (the photo-thermally induced ablation, the photo-mechanically induced ablation, the plasma induced ablation and the photoablation) and their fundamentals are herein described. The brief history of laser treatment modality in dermatology and urology are summarized.

A comparison of efficacy in ablative fractional laser assisted photodynamic therapy according to ablative depth for actinic keratosis

( Jeong-wan Seo ),( Yeo-rye Cho ),( Ho-jin Kim ),( Tae-hoon Kim ),( Ki-hoon Song ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

Background: Er:YAG ablative fractional laser-assisted photodynamic therapy (AFL-PDT) has shown significant benefit for the treatment of actinic keratosis(AK). However, no comparison of the PDT efficacy with ablative laser parameters has been completed. Objectives: To investigate whether the use of increased laser depth affects the efficacy, side effects, cosmetic outcomes, and protoporphyrin IX(PPIX) accumulation of AFL-PDT for facial AK. Methods: 309 AK lesions of 36 patients were included. Patients were randomly allocated to the 150-μm, 350-μ m, and 500-μm laser depth groups. After AFL was performed with either different laser depth, all patients underwent one session of PDT. Patients were followed up with at 1week, 1month, and 3months post treatment. Efficacy, side effects, cosmetic outcomes, and accumulated levels of PPIX were assessed. Results: Increasing laser depth did not enhance PPIX fluorescence. However, three months after treatment, the treatment of the higher laser depth groups(500μm) appeared to be significantly more effective than that of the lower laser depth groups(150μm) in terms of the management of Olsen grade III AK lesions. No significant differences were found with respect to side effects, cosmetic outcomes and safety. Conclusion: Higher laser depth does not increase PPIX accumulation, but does improve the treatment effect of AFL-PDT for high-grade AK lesions. We recommend AFL-PDT using higher laser depth parameters in cases of high-grade AK lesions.

Interaction of Laser Beam with PZT - Target and Observation of Laser - Induced Plume and Particle Ejection

이병우,Lee, Byeong-U Korean Society of Marine Engineers 1996 한국마린엔지니어링학회지 Vol.20 No.5

Laser-induced plume and laser-target interaction during pulsed laser deposition are demonstrated for a lead zirconate titanate (PZT). A KrF excimer laser (wavelength 248nm) was used and the laser was pulsed at 20Hz, with nominal pulse width of 20ns. The laser fluence was~$16J/cm^2,$ with 100mJ per pulse. The laser-induced plasma plume for nanosecond laser irradiation on PZT target has been investigated by optical emission spectra using an optical multichannel analyzer(OMA) and by direct observation of the plume using an ICCD high speed photography. OMA analysis showed two distinct ionic species with different expansion velocities of fast or slow according to their ionization states. The ion velocity of the front surface of the developing plume was about $10^7$cm/sec and corresponding kinetic energy was about 100eV. ICCD photograph showed another kind of even slower moving particles ejected from the target. These particles considered expelled molten parts of the target. SEM morphologies of the laser irradiated targets showed drastic melting and material removal by the laser pulse, and also showed the evidence of the molten particle ejection. The physics of the plasma(plume) formation and particle ejection has been discussed.

A Split-Face, Single-Blinded, Randomized Controlled Comparison of 532 nm Picosecond Neodymium-Doped Yttrium Aluminum Garnet Laser versus 532 nm Q-Switched Neodymium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Solar Lentigines

( Jung Yup Kim ),( Junghwa Yang ),( Gyoo Huh ),( Young-jun Choi ),( Won-serk Kim ) 대한피부과학회 2020 Annals of Dermatology Vol.32 No.1

Background: Solar lentigines are the most common form of benign epidermal pigmentation and one of the major cosmetic concerns in Korea. A 532 nm Q-switched neodymium: yttrium-aluminum-garnet (QSND) laser is typically used for the treatment, but the occurrence of post-inflammatory hyperpigmentation (PIH) is not rare. Recently, the use of picosecond (PS) lasers has emerged in pursuit of better outcomes. Objective: To objectively compare the efficacy and safety of 532 nm PS and QSND lasers for the treatment of solar lentigines. Methods: Twenty patients with solar lentigines were enrolled in a prospective, randomized split-face, single- blind study. One side of each face was treated using a 532 nm PS laser, and the other side using a 532 nm QSND laser. After one treatment, all patients were followed up for evaluation after 2, 4, 8, and 12 weeks. The clinical clearance was assessed by three blinded dermatologists using a 5-point quartile improvement scale (QIS). Subjective satisfaction, development of PIH, pain scale during treatment, and adverse problems were also recorded. Results: Clinical clearance measured by QIS showed that the PS laser was more effective than the QSND laser. Subjective satisfaction and pain scale did not significantly differ between the two groups. The incidence of PIH was 5% in sides treated with the PS laser, and 30% with the QSND laser. Conclusion: Both 532 nm PS laser and QSND laser were effective for the treatment of solar lentigines, but the PS laser was more effective with less PIH development. (Ann Dermatol 32(1) 8∼13, 2020)