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Three-dimensional residue-free volume removal inside sapphire by high-temperature etching after irradiation of femtosecond laser Pulses 飞秒激光脉冲辐照后蓝宝石内部高温蚀刻三维无残留体积去除
Laser Chemistry Pub Date : 2008-09-30 DOI: 10.1155/2008/892721
S. Matsuo, Kensuke Tokumi, T. Tomita, S. Hashimoto
{"title":"Three-dimensional residue-free volume removal inside sapphire by high-temperature etching after irradiation of femtosecond laser Pulses","authors":"S. Matsuo, Kensuke Tokumi, T. Tomita, S. Hashimoto","doi":"10.1155/2008/892721","DOIUrl":"https://doi.org/10.1155/2008/892721","url":null,"abstract":"We applied the femtosecond laser-assisted etching technique, that is, irradiation of focused femtosecond \u0000laser pulses followed by selective chemical etching, to volume removal inside sapphire. \u0000At room temperature, volume etching only slightly advanced while residue remained inside the \u0000volume. By increasing the etching temperature, complete volume etching without residue was \u0000achieved. Complete etching was, however, accompanied by undesirable phenomena of surface pits \u0000or cracks, which are expected to be excluded through further improvement of processing.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114032237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 12
Ultrafast Four-Wave Optical Parametric Amplification in Transparent Condensed Bulk Media 透明凝聚体介质中的超快四波光参量放大
Laser Chemistry Pub Date : 2008-09-21 DOI: 10.1155/2008/534951
A. Dubietis, G. Tamosauskas, G. Valiulis, A. Piskarskas
{"title":"Ultrafast Four-Wave Optical Parametric Amplification in Transparent Condensed Bulk Media","authors":"A. Dubietis, G. Tamosauskas, G. Valiulis, A. Piskarskas","doi":"10.1155/2008/534951","DOIUrl":"https://doi.org/10.1155/2008/534951","url":null,"abstract":"We present a short overview of recent advances in ultrashort pulse four-wave optical parametric \u0000amplification in transparent condensed bulk media with Kerr nonlinearity. Highly efficient (10% to 15% pump-to-signal energy conversion) four-wave optical parametric amplification in water and fused silica is experimentally demonstrated. The amplification process highly benefits from 1-dimensional spatial soliton propagation regime, which sets in under proper combination of cylindrical beam focusing and noncollinear phase matching geometry with millijoule pumping. Under these operating conditions, strong four-wave coupling quenches catastrophic beam break-up and filamentation, and the setup operates reasonably below the damage threshold of the nonlinear medium. The proposed methodology offers a number of advantages as compared to guided-wave configurations in gaseous media.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116450859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Induced Bragg Gratings in Optical Fibers and Waveguides Using an Ultrafast Infrared Laser and a Phase Mask 利用超快红外激光器和相位掩模在光纤和波导中诱导布拉格光栅
Laser Chemistry Pub Date : 2008-09-21 DOI: 10.1155/2008/416251
S. Mihailov, D. Grobnic, C. Smelser, P. Lu, R. Walker, H. Ding
{"title":"Induced Bragg Gratings in Optical Fibers and Waveguides Using an Ultrafast Infrared Laser and a Phase Mask","authors":"S. Mihailov, D. Grobnic, C. Smelser, P. Lu, R. Walker, H. Ding","doi":"10.1155/2008/416251","DOIUrl":"https://doi.org/10.1155/2008/416251","url":null,"abstract":"Since its development in 2003, the technique of Bragg grating inscription in optical fibers and waveguides with ultrafast infrared radiation and a phase mask has proven to be as simple as the standard UV-laser grating writing techniques but far more versatile. The ultrafast IR laser-based process allows for the creation of grating structures in glassy and crystalline materials that are not typically UV photosensitive. In this article, we will review the studies that have been performed at the Communications Research Centre Canada on the grating formation processes as well as applications of the ultrafast laser technique to fabricate gratings in various optical fibers and waveguides.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132178524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 41
Laser-Induced Photon-Branched Chain Reactionin a Chemically-Active Gas-Dispersed Medium 化学活性气体分散介质中激光诱导的光子支链反应
Laser Chemistry Pub Date : 2008-03-08 DOI: 10.1155/2008/839873
R. Letfullin, T. George, G. Duree
{"title":"Laser-Induced Photon-Branched Chain Reactionin a Chemically-Active Gas-Dispersed Medium","authors":"R. Letfullin, T. George, G. Duree","doi":"10.1155/2008/839873","DOIUrl":"https://doi.org/10.1155/2008/839873","url":null,"abstract":"A promising avenue in the development of high-energy pulsed chemical HF/DF lasers and amplifiers is the utilization of a photon-branched chain reaction initiated in a two-phase active medium, that is, a medium containing a laser working gas and ultradispersed passivated metal particles. These particles are evaporated under the action of IR laser radiation which \u0000 results in the appearance of free atoms, their diffusion into the gas, and the development of a photon-branching chain process, which involves photons as both reactants and products. The key obstacle here is the formation of a relatively large volume (in excess of 10 3 cm 3 ) of the stable active medium and filling this \u0000 volume homogeneously for a short time with a submicron monodisperse metal aerosol, which has specified properties. In this paper, results are presented for an extensive study of laser initiation of a photon-branched chain reaction in a gas-dispersed H 2 – F 2 medium.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133144757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Changes in Cell Viability of Wounded Fibroblasts following Laser Irradiation in Broad-Spectrum or Infrared Light 广谱或红外光激光照射后损伤成纤维细胞活力的变化
Laser Chemistry Pub Date : 2007-12-21 DOI: 10.1155/2007/71039
D. Hawkins, H. Abrahamse
{"title":"Changes in Cell Viability of Wounded Fibroblasts following Laser Irradiation in Broad-Spectrum or Infrared Light","authors":"D. Hawkins, H. Abrahamse","doi":"10.1155/2007/71039","DOIUrl":"https://doi.org/10.1155/2007/71039","url":null,"abstract":"Objective. This study aimed to establish if broad-spectrum or infrared (IR) light in combination with laser therapy can assist phototherapy to improve the cell function of wounded cells. Background. The effect of laser light may be partly or completely reduced by broad-spectrum light. Methods. Wounded human skin fibroblasts were irradiated with 5 J/ cm 2 using a helium-neon laser, a diode laser, or an Nd:YAG laser in the dark, in the light, or in IR. Changes in cell viability were evaluated by cell morphology, ATP cell viability, LDH membrane integrity, and caspase 3/7 as an early marker of apoptosis. Results. Wounded cells exposed to 5 J/ cm 2 using 632.8 nm in the dark or 830 nm in the light or 1064 nm in the dark showed an increase in ATP viability, an increase in cytokine expression, and a decrease in LDH cytotoxicity indicating that the metabolic activity of the wounded cells was stimulated. Conclusion. Wounded cells irradiated in IR light showed an undesirable thermal effect that was proportional to the duration of exposure.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131366720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 18
Cellular Damage in Diabetic Wounded Fibroblast Cells following Phototherapy at 632.8, 830, and 1064 nm 632.8、830和1064 nm光疗后糖尿病损伤成纤维细胞的细胞损伤
Laser Chemistry Pub Date : 2007-12-05 DOI: 10.1155/2007/80536
N. Houreld, H. Abrahamse
{"title":"Cellular Damage in Diabetic Wounded Fibroblast Cells following Phototherapy at 632.8, 830, and 1064 nm","authors":"N. Houreld, H. Abrahamse","doi":"10.1155/2007/80536","DOIUrl":"https://doi.org/10.1155/2007/80536","url":null,"abstract":"Objective. This study aimed to establish if laser irradiation induces cellular and genetic damage. Background. Phototherapy has been shown to induce wound healing in diabetic wounds, however little information is known regarding light-induced damage. Methods. Diabetic wounded fibroblasts were irradiated with 5 or 16 J/cm2 at 632.8, 830, and 1064 nm. Damage was assessed by measuring membrane and DNA damages. Cellular migration was determined by microscopy. Results. Cells irradiated with 5 J/cm2 at 632.8 and 830 nm showed a significant decrease in DNA damage while all cells irradiated with a fluence of 16 J/cm2 showed an increase in membrane and DNA damages. Conclusion. This study showed that the comet assay and LDH release were sensitive enough to pick up changes in laser-irradiated cells. This study also showed that cellular and genetic damage inflicted on diabetic wounded cells was dependent on dose and wavelength and that cells are able to recover and respond.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131108774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
Photostability of Uranine via Crossed-Beam Thermal Lens Technique 交叉光束热透镜技术研究铀的光稳定性
Laser Chemistry Pub Date : 2007-02-27 DOI: 10.1063/1.2711116
M. Z. el-din, K. Elsayed, M. Harith
{"title":"Photostability of Uranine via Crossed-Beam Thermal Lens Technique","authors":"M. Z. el-din, K. Elsayed, M. Harith","doi":"10.1063/1.2711116","DOIUrl":"https://doi.org/10.1063/1.2711116","url":null,"abstract":"Uranine is a diagnostic aid in ophthalmology and used as immuno‐histological stain. Photostability study on such important compound using crossed‐beam thermal lens (TL) technique was carried out. The study is based on the photodegradation (PD) behavior and rate regarding some parameters such as the incident laser power, wavelength, modulation frequency and sample concentration. The effects of such parameters on the TL signal and PD rate are discussed in details. The rate of PD is found to be proportional to the power of the pumping laser and concentration of the sample within the investigated range. The modulation frequency is found not to influence the PD rate. The photochemical quantum yield has been measured using potassium ferrioxalate actinometry and it was found to be very low.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123147763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Assisted Interpretation of Laser-Induced Fluorescence Spectra of Egg-Based Binding Media Using Total Emission Fluorescence Spectroscopy 全发射荧光光谱法辅助解释蛋基结合介质激光诱导荧光光谱
Laser Chemistry Pub Date : 2006-12-28 DOI: 10.1155/2006/82823
Austin Nevin, D. Anglos
{"title":"Assisted Interpretation of Laser-Induced Fluorescence Spectra of Egg-Based Binding Media Using Total Emission Fluorescence Spectroscopy","authors":"Austin Nevin, D. Anglos","doi":"10.1155/2006/82823","DOIUrl":"https://doi.org/10.1155/2006/82823","url":null,"abstract":"Laser-induced fluorescence (LIF) spectroscopy can provide nondestructive, qualitative analysis of protein-based binding media found in artworks. Fluorescence emissions from proteins in egg yolk and egg white are due to autofluorescent aromatic amino acids as well as other native and age-related fluorophores, but the potential of fluorescence spectroscopy for the differentiation between binding media is dependent on the choice of a suitable excitation wavelength and limited by problems in interpretation. However, a better understanding of emission spectra associated with LIF can be achieved following comparisons with total emission fluorescence spectra where a series of consecutive emission spectra are recorded over a specific range. Results using nanosecond UV laser sources for LIF of egg-based binding media are presented which are rationalised following comparisons with total emission spectra. Specifically, fluorescence is assigned to tryptophan and oxidation products of amino acids; in the case of egg yolk, fatty-acid polymerisation and age-related degradation products account for the formation of fluorophores.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130968524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 21
Characterization of Laser-Generated Microparticles by Means of a Dust Monitor and SEM Imaging 用粉尘监测仪和扫描电镜成像表征激光产生的微粒
Laser Chemistry Pub Date : 2006-12-27 DOI: 10.1155/2006/31862
R. Wurster, S. Pentzien, A. Conradi, J. Krüger
{"title":"Characterization of Laser-Generated Microparticles by Means of a Dust Monitor and SEM Imaging","authors":"R. Wurster, S. Pentzien, A. Conradi, J. Krüger","doi":"10.1155/2006/31862","DOIUrl":"https://doi.org/10.1155/2006/31862","url":null,"abstract":"Nanosecond laser (1064 nm wavelength) cleaning of artificially soiled paper as a model sample simulating a real-world artwork was performed. During the cleaning process, the ejection of particles was monitored in situ by means of a dust monitor (8 size classes, ranging from 0.3 μ m to > 2 μ m) and ex situ using a mini-cascade impactor (MKI, 5 stages). The cleaning \u0000result was analyzed by scanning electron microscopy (SEM) considering possible laser-induced damages to the substrate. Size distributions of emitted particles were measured depending on the processing parameters: laser fluence, F , and pulse number per spot, N . High numbers of large ( > 2 μ m) particles were collected by the mini-cascade impactor indicating \u0000a gas dynamical liftoff process. Obviously, these particles were not affected by the laser-matter interaction. The different methods (SEM, MKI, and dust monitor) are compared with respect to their usefulness for a proper interpretation of the cleaning results.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116290282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Laser Cleaning Tests on Archaeological Copper Alloys Using an ND:YAG Laser ND:YAG激光对考古铜合金的激光清洗试验
Laser Chemistry Pub Date : 2006-12-26 DOI: 10.1155/2006/75831
C. Korenberg, A. Baldwin
{"title":"Laser Cleaning Tests on Archaeological Copper Alloys Using an ND:YAG Laser","authors":"C. Korenberg, A. Baldwin","doi":"10.1155/2006/75831","DOIUrl":"https://doi.org/10.1155/2006/75831","url":null,"abstract":"Laser cleaning tests were performed on five archaeological copper alloy objects using a Q-switched Nd:YAG laser at 1064 nm. As a comparison, a section of each object was cleaned mechanically. Prior to cleaning, cross-sections were prepared to characterise the corrosion crust and help to locate the position of the original surface. Laser cleaning was not successful at removing burial deposits on two of the objects. For the other three objects, the laser removed most of the corrosion crust. This was not always satisfactory, as cleaning was sometimes accompanied by the loss of the original surface. In addition, laser-cleaned surfaces were matt compared to mechanically cleaned surfaces. In some instances, the former had a disfiguring purple hue which was attributed to the formation of particles that could be seen when examining the surface using scanning electron microscopy. For all the objects examined here, superior results were obtained by mechanical cleaning.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131385819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 15
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