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Sample records for gengival laser neodimio

  1. HIPERPLASIA GENGIVAL EM CRIANÇAS: USO DE ANTICONVULSIVANTES E HIGIENE ORAL

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    GUARÉ Renata de Oliveira

    1998-01-01

    Full Text Available A hiperplasia gengival tem sido relatada em pacientes tratados com vários anticonvulsivantes, sendo geralmente associada a presença de placa, inflamação gengival e predisposição genética. As autoras avaliaram, em 117 crianças de 4 a 19 anos do setor escolar da Associação de Assistência à Criança Defeituosa (AACD, o uso de drogas anticonvulsivantes por grupo etário, associando-as com o grau de hiperplasia gengival e de higiene bucal. Das crianças avaliadas, apenas 29,05% (34 crianças utilizavam medicação, sendo que, destas, 8,82% (3 crianças apresentavam hiperplasia gengival. Dentre os três grupos etários analisados, podemos inferir que uma eficiente higienização auxilia no controle e pode influir na presença de hiperplasia gengival

  2. FREQUÊNCIA DE HIGIENE BUCAL NA MANUTENÇÃO DA SAÚDE GENGIVAL

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    Tatiana Militz Perrone Pinto

    2012-01-01

    O objetivo deste ensaio clínico randomizado cego foi avaliar, em indivíduos com adequado método de higiene bucal, a frequência de remoção de placa para manter saúde gengival. Pacientes elegíveis (máximo 15% de sangramento gengival a sondagem) passaram por um período pré-experimental a fim de remover fatores que pudessem interferir no controle da placa, e alcançar saúde gengival (máximo 5% de sítios com sangramento gengival). Cinquenta e dois pacientes foram randomizados em quatro grupos de ac...

  3. Influência da exposição gengival na estética do sorriso

    OpenAIRE

    Dutra,Milene Brum; Ritter,Daltro Enéas; Borgatto,Adriano; Derech,Carla D'Agostine; Rocha,Roberto

    2011-01-01

    OBJETIVO: este estudo se propôs a avaliar a influência da quantidade de exposição gengival na estética do sorriso para os sexos feminino e masculino, e se existe diferença de opinião entre ortodontistas, clínicos gerais e pessoas leigas. MÉTODOS: utilizaram-se fotografias da face durante o sorriso de um indivíduo do sexo feminino e de um indivíduo do sexo masculino. As fotos foram alteradas digitalmente para produzir cinco diferentes níveis de exposição gengival, que variaram de exposição gen...

  4. Clinical study on the removal of gingival melanin pigmentation: comparison between Nd:YAG laser ablation and mechanical abrasion; Estudo clinico comparativo entre as tecnicas de despigmentacao melanica gengival: laser neodimio (1064 nm) e gengivoabrasao

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    Lopes, Luis Mario de Melo

    2002-07-01

    Melanin pigmentation occurs as a result of excessive deposition of melanin, produced by the melanocytes present in the basal layer of the epithelium. This study compares clinical parameters such as inflammation and/or hemorrhage, healing process and re-pigmentation, caused by the Nd:YAG laser ablation and the mechanical abrasion of the melanin, by means of photographic images, taken during the first 30 days after the treatment. The patients comfort was monitored during the first ten days after the treatment using the method of the Visual Analog Scale to measure the pain. Six patients with gingival melanin pigmentation were selected. The left upper gingival quadrant was treated with the Nd:YAG laser using 125 mJ per pulse and 20 Hz, the right upper gingival quadrant received mechanical abrasion and the lower quadrants served for control. Both techniques did not result in inflammation and/or hemorrhage. The healing process was slower with the laser. Using mechanical abrasion, ali patients showed remaining pigmentation or re-pigmentation of varying intensity after a period of 30 days. With the laser 50 % of the patients did not show any re-pigmentation after this period. The pain analysis showed that the pain sensed 24 hours after the treatment with the laser is higher than using mechanical abrasion. (author)

  5. Hipertrofia gengival em transplantados renais Cyclosporine induced gingival hyperplasia in kidney transplants

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    Paulo Roberto Torrezan

    2005-08-01

    Full Text Available OBJETIVO: Avaliar os fatores associados ao crescimento gengival excessivo em transplantados renais. MÉTODOS: A pesquisa foi realizada no Hospital Cajuru de Curitiba, no período de abril a outubro de 2002, com a participação de 60 transplantados renais, em uso diário de ciclosporina e com pelo menos um segmento dentário. O protocolo de ensaio foi observacional transversal. O exame odontológico dos indivíduos consistiu da avaliação dos segmentos dentários com verificação do grau de crescimento da gengiva e do índice de placa bacteriana. Todos os participantes preencheram questionário com dados relacionados ao transplante renal, realizaram coleta de material para controle do nível sérico de ciclosporina e foram avaliados quanto ao peso e altura. Na comparação dos resultados de amostras categóricas, utilizou-se o teste do Qui-quadrado e a correlação de classes de Spearman. O teste t foi aplicado na comparação das variáveis contínuas. RESULTADOS: Em pacientes tratados somente com ciclosporina, 47,2% não apresentavam alterações da gengiva, enquanto 52,8% cursaram com crescimento gengival, sendo 30,6% com grau > 2. Nos pacientes tratados com ciclosporina e nifedipina, notou-se que 29,2% tinham gengiva normal e 70,8% apresentaram crescimento gengival, sendo que em 45,8% o comprometimento foi grau > 2. Não foi observada diferença significativa dos resultados entre os gêneros masculino e feminino. Foi encontrada correlação positiva entre o índice de placa bacteriana e o volume gengival (r = 0,3295; pOBJECTIVE: Assess the influence of cyclosporine on the gingival growth of 60 patients with kidney transplant through a research carried out at the Hospital Cajuru in Curitiba, (April to October of 2002. METHODS: Regardless of age, gender, ethnic or social condition, all patients received cyclosporine daily and had, at least, one dental segment. They monthly returned to the Hospital for medical control and for several

  6. Motivação no controle do biofilme dental e sangramento gengival em escolares Motivation on plaque control and gengival bleeding in school children

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    Ramona Fernanda Ceriotti Toassi

    2002-10-01

    Full Text Available O objetivo do estudo foi avaliar a eficácia de duas estratégias motivacionais em relação ao controle do biofilme dental e sangramento gengival em 135 escolares da rede estadual e municipal de ensino do município de Santa Tereza, RS, 1999. O programa de motivação a que os escolares tinham acesso constou da utilização de diversos recursos aplicados em dois grupos de intervenção: Grupo A, motivação em sessão única, e Grupo B, motivação em quatro sessões. Para a avaliação da metodologia empregada foram realizados levantamentos do índice de placa visível (IPV de Ainamo & Bay (1975, e do índice de sangramento gengival (ISG. Em ambos os grupos houve redução tanto do ISG quanto do IPV após as sessões de intervenção (pThe objective of the study is to evaluate the impact of two pedagogical motivational approaches for plaque and gingival bleeding control among 135 students of local public schools in Santa Tereza, Brazil, in 1999 The motivational program consisted of different educational strategies offered to two distinct groups: Group A, who attended only one explanatory session about oral hygiene, and Group B, who attended a total of four pedagogical sessions. In order to evaluate the methodology applied, the visible plaque index (according to Ainamo & Bay, 1975 and gingival bleeding index (according to Löe and Silness, 1963 were calculated. A highly statistically significant reduction in the visible plaque index and gingival bleeding index was observed in both groups after the educational sessions (p<0.001. Moreover, a higher reduction in the gingival bleeding index and an even more accentuated decrease in the visible plaque index was found in group B when compared to group A (p<0.001. In conclusion, the motivational reinforcement in educational and preventive programs has a positive effect for the reduction and control of gingival bleeding and bacterial plaque.

  7. Superinfecting microorganisms in patients under treatment with cyclosporin-A and its correlation to gingival overgrowth Microrganismos superinfectantes em pacientes submetidos a terapia com ciclosporina-A e sua correlação com crescimento gengival

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    Giuseppe Alexandre Romito

    2003-03-01

    Full Text Available The aim of this study was to identify the presence of superinfecting microorganisms (Gram-negative enteric rods and Candida sp. in heart transplant patients and correlate this with gingival overgrowth. Thirty patients (10 females, 20 males - mean age 45 years were examined. All were under cyclosporin-A (CsA therapy. Patients who had taken any antibiotics 3 months prior the study or had been submitted to periodontal therapy were not enrolled. Patients were required to have at least 6 teeth. The plaque index (PI, gingival index (GI, pocket depth (PD and clinical attachment level (CAL were recorded. Microbiological samples were taken from sulcus/pocket (s/p and from stimulated saliva (ss and submitted to analysis. Patients were divided into two groups: the ones with gingival overgrowth (GO and those without gingival overgrowth (WGO. After statistical analysis (chi-square test, Student's t-test, Fisher test, p A proposta deste trabalho foi identificar a presença de microrganismos superinfectantes (bastonetes entéricos Gram-negativos e Candida sp. em pacientes transplantados cardíacos e correlacioná-la com a presença de crescimento gengival. Foram examinados 30 pacientes (10 mulheres e 20 homens - média de idade: 45 anos. Todos os pacientes estavam sob terapia com ciclosporina-A (CsA sem terem sido submetidos a antibioticoterapia e nem a tratamento periodontal prévio, por pelo menos três meses antes do início do estudo. O paciente deveria ter, no mínimo, seis dentes. Foram registrados os índices de placa bacteriana (IP, índice gengival (IG, valores de profundidade clínica de sondagem (PCS e nível clínico de inserção (NCI. Análise microbiológica foi realizada a partir de amostras coletadas de sulco/bolsa gengival (s/b e da saliva estimulada (se. Os pacientes foram divididos em dois grupos: com crescimento gengival (CCG e sem crescimento gengival (SCG. Após análise estatística (teste do qui-quadrado; teste t de Student; prova

  8. Avaliação da condição gengival e microbiológica subgengival de pacientes sadios periodontalmente submetidos a tratamento ortodôntico

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    Menezes Cardoso, Randerson

    2011-01-01

    Objetivo: Avaliar a condição gengival e a presença na microbiota subgengival das bactérias Aggregatibacter actinomycetemcomitans (Aa) e Tannerella forsythia (Tf) em pacientes periodontalmente saudáveis submetidos a tratamento ortodôntico com aparelho fixo. Material e Métodos: Vinte pacientes foram distribuídos em dois grupos (n=10) de acordo com a necessidade de tratamento ortodôntico (Grupo Teste = apresentavam má oclusão e receberam tratamento ortodôntico; Grupo Controle =...

  9. Estudo dos parâmetros periodontais para a avaliação morfológica da papila gengival interdental na região anterior da maxila

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    Marinho, Carlos Frederico de Carvalho

    2007-01-01

    O alto grau de exigência estética de pacientes e profissionais no atual estágio da implantodontia implica num exame de diagnóstico extremamente apurado, devido as possíveis alterações na margem gengival e na papila interproximal advindas do tratamento com implantes unitários. O objetivo deste trabalho foi avaliar o efeito dos parâmetros periodontais sobre a altura da papila interdental na região de incisivos centrais, incisivos laterais, caninos e primeiros pré-molares superior...

  10. Influência da exposição gengival na estética do sorriso Influence of gingival exposure on the smile aesthetics

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    Milene Brum Dutra

    2011-10-01

    Full Text Available OBJETIVO: este estudo se propôs a avaliar a influência da quantidade de exposição gengival na estética do sorriso para os sexos feminino e masculino, e se existe diferença de opinião entre ortodontistas, clínicos gerais e pessoas leigas. MÉTODOS: utilizaram-se fotografias da face durante o sorriso de um indivíduo do sexo feminino e de um indivíduo do sexo masculino. As fotos foram alteradas digitalmente para produzir cinco diferentes níveis de exposição gengival, que variaram de exposição gengival de 4mm até a cobertura dos incisivos superiores pelo lábio superior em 4mm. As fotografias foram impressas em tamanho real da face, dispostas aleatoriamente em um álbum e foram classificadas por 30 ortodontistas, 30 clínicos gerais e 30 leigos, quanto à atratividade do sorriso, em péssimo, ruim, regular, bom ou ótimo. RESULTADOS: o sorriso mais estético para o indivíduo do sexo feminino, tanto para ortodontistas, clínicos gerais e leigos, foi aquele em que o lábio superior repousa na margem cervical dos incisivos superiores, mostrando toda a coroa dos incisivos (pOBJECTIVE: The purpose of this study is to evaluate the gingival exposition influence on the smile esthetics and if exists different opinions about it between orthodontists, clinical dentists and lay person. METHODS: Photographs of male and female smiling faces were manipulated on the computer with different gingival exposition levels, which ranges from 4 mm gingival exposition to 4 mm upper lip incisor coverage. The photos were printed on a real face size, placed unordered to be analyzed by 30 orthodontists, 30 clinical dentists and 30 lay person. They had to rate between very bad, bad, regular, good and very good judging on smile attractiveness. RESULTS: The more attractive smile for the female individuals judged by the orthodontists, clinical dentists and lay person were the one in which the upper lip rest on the cervical edge on the upper incisor, showing all the

  11. Saúde gengival de adolescentes e a utilização de serviços odontológicos, Estado de São Paulo Gingival health of adolescents and the utilization of dental services, state of São Paulo, Brazil

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    José Leopoldo Ferreira Antunes

    2008-04-01

    Full Text Available OBJETIVO: Avaliar a associação de condições de saúde gengival com a utilização de serviço odontológico. MÉTODOS: Realizou-se levantamento epidemiológico de saúde bucal de 1.799 adolescentes, em 35 cidades do Estado de São Paulo, em 2002. A saúde gengival foi avaliada pela prevalência de sangramento na gengiva à sondagem e cálculo dentário (índice periodontal comunitário e oclusão dentária (índice de estética dentária. A utilização de serviços odontológicos foi medida pelo índice de cuidado (O/CPO para cada cidade. Análise multinível de regressão logística ajustou modelos explicativos para fatores associados aos desfechos de interesse. RESULTADOS: A prevalência de sangramento gengival à sondagem foi 21,5%; de cálculo dentário foi 19,4%. Os participantes do sexo masculino, negros e pardos, moradores em áreas rurais, residentes em domicílios aglomerados e com atraso escolar apresentaram chance significantemente mais elevada para os agravos que seus respectivos pares de comparação. Características de oclusão dentária também associaram com gengiva não-saudável: apinhamento dos segmentos incisais, mordida aberta vertical anterior, relação molar antero-posterior. Cidades com maior utilização de serviço odontológico tiveram menor proporção de adolescentes com sangramento gengival e cálculo. CONCLUSÕES: A utilização de serviços odontológicos foi significativamente associada a melhores condições de saúde gengival (sangramento e cálculo. Essa associação independeu das características sociodemográficas individuais e contextuais, e de oclusão dentária.OBJECTIVE: To evaluate the association between gingival health conditions and dental service utilization. METHODS: An epidemiological survey of the oral health of 1,799 adolescents was carried out in 35 cities of the state of São Paulo, in 2002. Gingival health was assessed through the prevalence of gingival bleeding on probing and dental

  12. Chemical and physical analysis on hard tissues after irradiation with short pulse Nd:YAG laser; Alteracoes quimicas e fisicas de tecidos duros irradiados por laser de neodimio chaveado

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    Pereira, Andrea Antunes

    2003-07-01

    This work reports on a study that was designed to investigate chemical, physical and morphological alterations in the dental enamel surface. The influence of application of laser in enamel surface by microscopic technical, X-ray fluorescence for chemical analysis, physical property as well as hardness and thermal analysis with Nd:YAG laser is also pointed out. A prototype of Nd:YAG (Q-switched) laser developed at the Center of Lasers and Applications - Institute of Energetic and Nuclear Research, aiming applications in the Medical Sciences that typical wavelength of 1.064 nm was used. The modifications in human dental enamel chemical composition for major and trace elements are here outlined. The accuracy of procedures was performed by analysis of natural hydroxyapatite as standard reference material. The identification and quantification of the chemical elements presented in the dental tissue samples were performed trough EDS, XRF and INAA. We determined the rate Calcium/Phosphorus (Ca/P) for different techniques. We performed an analysis in different regions of the surface and for different areas allowing a description of the chemical change in the total area of the specimen and the assessment of the compositional homogeneity of the each specimen. A comparison between XRF and INAA is presented. Based on morphological analysis of the irradiated surfaces with short pulse Nd:YAG laser we determined the area surrounded by the irradiation for the parameters for this thesis, and this technique allowed us to visualize the regions of fusion and re-solidification. The energy densities ranged from 10 J/cm{sup 2} to 40 J/cm{sup 2}, with pulse width of 6, 10 e 200 ns, and repetition rates of 5 and 7 Hz. In this thesis, FTIR-spectroscopy is used to analyze powder of mineralized tissue as well as enamel, dentine, root and cementum for human and bovine teeth after irradiation with short-pulse Nd:YAG laser. Characteristic spectra were obtained for the proteins components and

  13. Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

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    Carlos Vallejos; Job Balladares

    2014-01-01

    La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes d...

  14. Modeling of thermal and optical effects in dental pulp during the irradiation with neodymium and diode lasers; Modelagem dos efeitos termicos e opticos na polpa dentaria durante a irradiacao com os lasers de diodo de neodimio

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    Farhat, Patricia Bahls de Almeida

    2003-07-01

    During the development of applications of high intensity lasers in the enamel and dentine, adverse thermal effects into the entire dental structure, including the pulp, must be verified. The measurement of the temperature in the intact pulp, however, is not a solved problem. For this purpose, models have been used frequently, using extracted teeth, with pulpal cavities filled with materials that simulate only thermal properties of the pulp. Current models, however, do not simulate optical properties of the pulp, not taking the remaining radiation in the pulp chamber into account. The aim of this study was to verify if the remaining radiation from neodymium and diode lasers that reach the pulp chamber, at the models using extracted bovine teeth, can cause local thermal effects. For this purpose, two models were developed, using extracted bovine teeth with their pulp chambers filled with water (simulating pulp thermal characteristics) without (model 1) and with (model 2) an optical absorbent. Models were radiated with 1 W. The obtained results show that, for both lasers, the temperature rise in model 2 pulp chamber is: up to 11 % higher than in the model 1 when the enamel is radiated; and up to 37% higher than in the model 1 when dentine is radiated (1 mm from the pulp), indicating that the level of the remaining radiation is relevant for the construction of models excited by the neodymium and diode lasers. (author)

  15. O uso do laser na reabilitação das desordens temporomandibulares

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    Thiago de Oliveira Assis

    Full Text Available INTRODUÇÃO: Entende-se disfunção temporomandibular comoum termo coletivo que envolve um grande número de problemas clínicos que afetam os músculos mastigatórios, a articulação temporomandibular (ATM e estruturas associadas. Dentre os principais sinais e sintomas, incluem-se dores nos músculos da mastigação ou na ATM, ruídos articulares, limitação de abertura, retração gengival, oclusão inadequada, distúrbios auditivos, cefaleias, sensibilidade em toda a musculatura do sistema estomatognático e cervical. OBJETIVOS: Estudar a influência da laserterapia de baixa intensidade (diodo no tratamento das desordens temporomandibulares. MATERIAIS E MÉTODOS: Trata-se de uma revisão sistemática. Foram consultadas as seguintes bases de dados: BIREME, MEDLINE, PubMed, Science Direct e LILACS. Os termos de busca utilizados foram "temporomandibular laser therapy" e "ATM laser treatment", em inglês e português. Não foram estabelecidos limites de busca. Após a busca independente de dois revisores, foram encontrados 1.344 artigos e, após a aplicação dos critérios de exclusão, 12 artigos foram selecionados para a análise. RESULTADOS: Dos 12 artigos selecionados, apenas em 1 (um deles não foi verificada qualquer melhora do quadro doloroso na ATM em virtude dos diversos tipos de DTM. CONCLUSÃO: Apesar dos resultados satisfatórios do uso do laser na redução sintomática da dor nos DTM, ainda é controversa a utilização dos seus parâmetros para cada caso. Por isso, sugerimos a realização de outros estudos para que essas lacunas sejam preenchidas com o objetivo maior de promover uma melhor qualidade de vida para as pessoas que sofrem quaisquer transtornos na região da ATM.

  16. Efectividad del Nd- Yag láser en la capsulotomía posterior Effectiveness of Nd-Yag laser in posterior capsulotomy

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    Alina Pedroso Llanes

    2004-06-01

    Full Text Available Este trabajo se propuso determinar la efectividad del neodimio YAG láser (Nd-YAG láser en la realización de capsulotomía posterior a 150 pacientes (ojos operados de catarata senil o presenil en el centro de Microcirugía Ocular en Serie del Hospital Oftalmológico Docente "Ramón Pando Ferrer" en el período comprendido de febreroa diciembre de 1999. En este grupo se analizaron como variables la edad, sexo, raza, implante o no de lente intraocular, tipo de opacidad de cápsula posterior, agudeza visual con corrección pre y postratamiento, complicaciones encontradas, comportamiento de la presión intraocular, así como la energía empleada para realizar dicho proceder. Estos datos se analizaron a través de tablas de contingencias Chi cuadrado. Como resultado de esta investigación se encontró que el láser es altamente efectivo para el mejoramiento de la agudeza visual en los pacientes afectados de catarata secundaria (74,7 %. Se observó además aumento transitorio de la presión intraocular en las dos primeras horas posteriores al láser (60,7 %, y no se encontró ninguna complicación que afectara la visión de los ojos estudiadosThe aim of this paper was to determine the effectiveness of neodymium YAG laser (Nd-YAG laser on performing the posterior capsulotomy in 150 patients (eyes operated on of senile or presenile cataract at the Center of Serial Ocular Microsurgery (CSOM of "Ramón Pando Ferrer" Ophthalmological Teaching Hospital from February to December 1999. Age, sex, race, implantation or not of the intraocular lens (IOL, type of opacity of the posterior capsule, visual acuity with pre- and posttreatment correction (Avcc, complications found, behavior of the intraocular pressure (IOP, as well as the energy used to carry out such procedure, were analyzed. The Chi square contingency tables were used to this end. As a result of this research, it was found that the laser is highly effective for improving visual acuity in patients

  17. Gingival healing after gingivectomy procedure and low intensity laser irradiation. A clinical and biometrical study in anima nobile; Reparacao gengival apos a tecnica de gengivectomia e aplicacao de laser em baixa intensidade. Avaliacao clinica e biometrica em humanos

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    Amorim, Jose Claudio Faria

    2001-07-01

    For the present study seven patients presenting periodontal disease were selected in a way that they required the performance of gingivectomy procedure in the region of premolars in both sides, being this in the upper or lower region. After the surgical procedure one side was submitted to low intensity laser radiation, wavelength 685 nm, power 50 mW and fluency of 4J/cm{sup 2}, contact mode. The other side was used as a control, not receiving any laser irradiation. Healing process for both sides, was clinically and biometrically evaluated and compared using photographs for the periods: pre-operative, immediate post-operative, 3, 7,14,21, 28 and 35 days. The analysis was performed by 3 specialists in Periodontology considering aspects of healing. Results were submitted to statistical analysis. Biometrical evaluation showed improvement of healing for the period of 21 and 28 days in the lased group. Clinical evaluation showed better reparation mainly after the third day for the active group. Laser group was considered to present an improved healing when compared to the control group. (author)

  18. Vilkår og muligheder i det sociale web

    DEFF Research Database (Denmark)

    2009-01-01

    Dette podcast gengiver et indlæg på Forskningsnetkonferencen 2007 om muligheder og vilkår i det sociale web med særligt henblik på e-læring. Fysisk medie: Flash-fil......Dette podcast gengiver et indlæg på Forskningsnetkonferencen 2007 om muligheder og vilkår i det sociale web med særligt henblik på e-læring. Fysisk medie: Flash-fil...

  19. Avaliação in vitro da microinfiltração em cavidades classe II de molares decíduos, restaurados com resina composta auto e fotopolimerizável

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    CAVALCANTI Alessandro Leite; CHELOTTI Adolpho

    1999-01-01

    Estudou-se a microinfiltração marginal presente na interface da parede gengival de cavidades classe II em molares decíduos, restaurados com resina composta (auto e fotopolimerizável), através da penetração de uma solução corante. Os preparos cavitários apresentavam a parede gengival em esmalte e foram restaurados segundo 4 diferentes técnicas: 1) resina composta fotopolimerizável; 2) resina composta autopolimerizável; 3) resina composta auto e fotopolimerizável; e 4) ionômero de vidro/resina ...

  20. Estudo dos efeitos vasculares secundários à presença de periodontite em ratos.

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    Paula Campi Locatelli Favalli

    2012-01-01

    A destruição crônica do aparelho de inserção periodontal devido a uma intensa resposta inflamatória a bactérias conduz a uma condição clínica conhecida como doença periodontal. A inflamação periodontal geralmente provoca úlceras superficiais no sulco gengival, onde os capilares sanguíneos estão expostos a bactérias. Patógenos periodontais, assim como seus produtos podem ser translocados e liberados do sulco gengival para a corrente sanguínea e, portanto, ter efeitos periféricos. A bolsa perio...

  1. Bráquetes convencionais e autoligados: detecção de micro-organismos na saliva e in situ, avaliação de parâmetros periodontais e quantificação de citocinas no fluido crevicular

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    Ana Zilda Nazar Bergamo

    2014-01-01

    O aparelho ortodôntico promove alterações microbiológicas na cavidade bucal, em função da variedade de materiais sólidos e elásticos que possuem, os quais funcionam como áreas de retenção, levando a um acúmulo de biofilme e predispondo o hospedeiro à cárie dental e à doença periodontal. Os objetivos do presente estudo, in vivo, foram: 1) Avaliar, as alterações no índice de placa (PI), índice gengival (GI), índice de sangramento gengival (GBI) e no volume do fluido crevicular, em pacientes com...

  2. Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

    Directory of Open Access Journals (Sweden)

    Carlos Vallejos

    2014-12-01

    Full Text Available La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes de desechos tecnológicos. Como resultado de la investigación se concluyó que tales imanes son aptos para este propósito, con un rango de optimización en la combustión del gas de entre el 13 y el 20%. Esto pudo demostrarse mediante la aplicación de principios generales de la mecánica de fluidos, del campo magnético y de la termodinámica. Los resultados contribuyen a la búsqueda de estrategias para disminuir el uso de combustibles fosiles en los hogares y otros espacios donde se utiliza gas licuado para la cocción de los alimentos, así cómo para contribuir al bienestar de la microeconomía.

  3. Avaliação in vitro da microinfiltração em cavidades classe II de molares decíduos, restaurados com resina composta auto e fotopolimerizável

    Directory of Open Access Journals (Sweden)

    CAVALCANTI Alessandro Leite

    1999-01-01

    Full Text Available Estudou-se a microinfiltração marginal presente na interface da parede gengival de cavidades classe II em molares decíduos, restaurados com resina composta (auto e fotopolimerizável, através da penetração de uma solução corante. Os preparos cavitários apresentavam a parede gengival em esmalte e foram restaurados segundo 4 diferentes técnicas: 1 resina composta fotopolimerizável; 2 resina composta autopolimerizável; 3 resina composta auto e fotopolimerizável; e 4 ionômero de vidro/resina composta. Após a análise estatística dos resultados, concluiu-se que todos os grupos apresentaram microinfiltração em graus variados; todavia, os grupos 2, 3 e 4 apresentaram os menores graus de infiltração.

  4. New solid laser: Ceramic laser. From ultra stable laser to ultra high output laser

    International Nuclear Information System (INIS)

    Ueda, Kenichi

    2006-01-01

    An epoch-making solid laser is developed. It is ceramic laser, polycrystal, which is produced as same as glass and shows ultra high output. Ti 3+ :Al 2 O 3 laser crystal and the CPA (chirped pulse amplification) technique realized new ultra high output lasers. Japan has developed various kinds of ceramic lasers, from 10 -2 to 67 x 10 3 w average output, since 1995. These ceramic lasers were studied by gravitational radiation astronomy. The scattering coefficient of ceramic laser is smaller than single crystals. The new fast ignition method is proposed by Institute of Laser Engineering of Osaka University, Japan. Ultra-intense short pulse laser can inject the required energy to the high-density imploded core plasma within the core disassembling time. Ti 3+ :Al 2 O 3 crystal for laser, ceramic YAG of large caliber for 100 kW, transparent laser ceramic from nano-crystals, crystal grain and boundary layer between grains, the scattering coefficient of single crystal and ceramic, and the derived release cross section of Yb:YAG ceramic are described. (S.Y.)

  5. Software og kvalitativ dataanalyse

    DEFF Research Database (Denmark)

    Kristiansen, Søren

    Denne bog handler om brug af softwareprogrammer til håndtering og analyse af kvalitative data. Den gengiver og diskuterer nogle af de væsentligste problemstillinger, muligheder og perspektiver, som knytter sig til indførelsen af softwareredskaber til analyse af kvalitative data med udgangspunkt i...

  6. Isolamento e caracterização de fibroblastos gengivais positivos para fosfatase alcalina de pacientes portadores de periodontite crônica e hiperplasia gengival medicamentosa = Isolation and characterization of gingival fibroblasts positive for alkaline phosphatase in patients with chronic periodontitis and drug-induced gingival hyperplasia

    Directory of Open Access Journals (Sweden)

    Santos, Vagner Rodrigues

    2010-01-01

    Full Text Available Objetivo: Investigar a expressão da atividade de fosfatase alcalina (ALP em fibroblastos gengivais de sujeitos com periodontite crônica (PC e hiperplasia gengival medicamentosa (HGM induzida por difenilhidantoína. Metodologia: Os fragmentos gengivais foram obtidos de 13 pacientes (8 mulheres e 5 homens, 22 a 74 anos, sendo 4 fragmentos procedentes de gengiva clinicamente normal (GN, 5 de biópsias de bolsas periodontais com PC e 4 de HGM induzida pela difenilhidantoína. Através de digestão enzimática, suspensões de células gengivais foram preparadas contendo fibroblastos ALP-positivos sem afetar a atividade da enzima ALP. Análises citoquímica e histoquímica foram realizadas. Resultados: Fibroblastos de GN apresentaram fraca positividade para ALP quando comparados com PC e HGM. PC e HGM exibiram níveis elevados e intermediários, respectivamente, de ALP. Observou-se menor proliferação celular na cultura de células em PC e HGM que em GN. Entretanto, a quantidade de células recuperadas das sub-culturas foi similar à quantidade recuperada na cultura inicial para as três linhagens. Conclusões: A expressão de ALP na PC e na HGM encontra-se aumentada e ocorre baixa proliferação de fibroblastos na PC e na HGM. Isto sugere que a inflamação periodontal e a difenilhidantoína podem influenciar a expressão de ALP e a multiplicação de fibroblastos gengivais humanos. Outros estudos são necessários para melhor avaliar a importância de ALP no desenvolvimento e na progressão de PC e HGM

  7. Laser-diode pumped Nd:YAG lasers; Laser diode reiki Nd:YAG lasear

    Energy Technology Data Exchange (ETDEWEB)

    Yuasa, H.; Akiyama, Y.; Nakayama, M. [Toshiba Corp., Tokyo (Japan)

    2000-04-01

    Laser-diode pumped Nd:YAG lasers are expected to be applied to laser processing fields such as welding, cutting, drilling, and marking due to their potential for high efficiency and compactness. We are designing and developing laser-diode pumped Nd:YAG lasers using numerical analysis simulation techniques such as ray tracing and thermal analysis. We have succeeded in achieving a laser power of more than 3 kW with 20% efficiency, which is the best ever obtained. In addition, we have developed a laser-diode pumped green laser by second harmonic generation, for precision machining on silicon wafers. (author)

  8. Lasers '89

    International Nuclear Information System (INIS)

    Harris, D.G.; Shay, T.M.

    1990-01-01

    This book covers the following topics: XUV, X-Ray and Gamma-Ray Lasers, excimer lasers, chemical lasers, nuclear pumped lasers, high power gas lasers, solid state lasers, laser spectroscopy. The paper presented include: Development of KrF lasers for fusion and Nuclear driven solid-state lasers

  9. Laser safety at high profile laser facilities

    International Nuclear Information System (INIS)

    Barat, K.

    2010-01-01

    Complete text of publication follows. Laser safety has been an active concern of laser users since the invention of the laser. Formal standards were developed in the early 1970's and still continue to be developed and refined. The goal of these standards is to give users guidance on the use of laser and consistent safety guidance and requirements for laser manufacturers. Laser safety in the typical research setting (government laboratory or university) is the greatest challenge to the laser user and laser safety officer. This is due to two factors. First, the very nature of research can put the user at risk; consider active manipulation of laser optics and beam paths, and user work with energized systems. Second, a laser safety culture that seems to accept laser injuries as part of the graduate student educational process. The fact is, laser safety at research settings, laboratories and universities still has long way to go. Major laser facilities have taken a more rigid and serious view of laser safety, its controls and procedures. Part of the rationale for this is that these facilities draw users from all around the world presenting the facility with a work force of users coming from a wide mix of laser safety cultures. Another factor is funding sources do not like bad publicity which can come from laser accidents and a poor safety record. The fact is that injuries, equipment damage and lost staff time slow down progress. Hence high profile/large laser projects need to adapt a higher safety regimen both from an engineering and administrative point of view. This presentation will discuss all these points and present examples. Acknowledgement. This work has been supported by the University of California, Director, Office of Science.

  10. Influência do complexo flúor-xilitol no controle da placa dentária e do sangramento gengival em pacientes herbiátricos com aparelho ortodôntico fixo Influence of fluorine-xylitol complex in the dental plaque and gingival bleeding control in herbiatric patients with fixed orthodontic brace

    Directory of Open Access Journals (Sweden)

    Fabíola Elias

    2006-10-01

    Full Text Available OBJETIVO: avaliar os efeitos de um dentifrício contendo flúor/xilitol na redução da adesão da placa à estrutura dentária, bem como no índice de sangramento gengival, em portadores de aparelho ortodôntico fixo. METODOLOGIA: foram avaliados 22 jovens, com idade entre 14 e 17 anos. Após a quantificação inicial dos índices, os jovens receberam instruções de escovação e começaram a utilizar somente os dentifrícios da pesquisa. Houve uma divisão aleatória da amostra em dois grupos (A e B. Na primeira semana todos utilizaram um dentifrício padrão e a partir da segunda semana os jovens do grupo A receberam um dentifrício contendo flúor, enquanto os do grupo B receberam um dentifrício contendo o complexo flúor-xilitol, que utilizaram durante vinte e oito dias, quando foram novamente avaliados (T1. Para a segunda fase (T2 houve inversão dos dentifrícios. RESULTADOS: foram comparados os resultados intra-grupo e nos dois grupos houve redução estatisticamente significante entre as fases inicial e T1, inicial e T2 e entre T1 e T2. Já na comparação entre os grupos não houve diferença estatisticamente significante entre eles, embora o dentifrício contendo flúor/xilitol tenha proporcionado uma porcentagem de redução do índice de sangramento gengival maior que o dentifrício contendo apenas o fluoreto de sódio, principalmente entre as fases inicial e T2, onde a redução no grupo A foi de 90,13% e no grupo B foi de 78,84%. CONCLUSÃO: a utilização de dentifrícios contendo flúor e xilitol, associada à instrução e motivação, parece ser um recurso bastante promissor para a manutenção da saúde bucal nos pacientes ortodônticos.AIM: to evaluate the effects of a dentifrice containing fluorine/xylitol in the reduction of the adhesion of the plaque to the dental structure, as well as in the gingival bleeding index in patients who had orthodontic braces. METHODS: 22 teenagers, in between 14 and 17 years old were

  11. Laser in urology. Laser i urologien

    Energy Technology Data Exchange (ETDEWEB)

    Breisland, H.O. (Aker Sykehus, Oslo (Norway))

    1991-09-01

    The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs.

  12. Laser system using ultra-short laser pulses

    Science.gov (United States)

    Dantus, Marcos [Okemos, MI; Lozovoy, Vadim V [Okemos, MI; Comstock, Matthew [Milford, MI

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  13. Application of Various Lasers to Laser Trimming Resistance System

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-feng

    2007-01-01

    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  14. Laser optically pumped by laser-produced plasma

    International Nuclear Information System (INIS)

    Silfvast, W.T.; Wood, O.R. II.

    1975-01-01

    Laser solids, liquids and gases are pumped by a new technique in which the output from an efficient molecular laser, such as a CO 2 laser, ionizes a medium, such as xenon, into a generally cylindrical plasma volume, in proximity to the pumped laser body. Breakdown yields a visible and ultraviolet-radiation-emitting plasma in that volume to pump the laser body. The spectral radiance of the plasma is significantly higher than that produced by a dc-discharge-heated plasma at nearly all wavelengths in the plasma spectrum. The risetime of radiation from the laser-produced plasma can also be significantly shorter than that of a dc heated plasma. A further advantage resides in the fact that in some applications the attenuating walls needed by flashlamps may be eliminated with the result that laser threshold is more readily reached. Traveling wave excitation may be provided by oblique incidence of the pumping laser beam through the ionizable medium to create sequential ionization of portions of that medium along the length of the pumped laser body. (auth)

  15. Diode laser-pumped Ho:YLF laser

    International Nuclear Information System (INIS)

    Hemmati, H.

    1987-01-01

    The author reports laser action in Ho:YLF at 2.06 μm following optical pumping with a cw diode laser array. Diode laser-pumped Nd-YAG and Ho:YAG have been reported recently. Lasers with a wavelength of 2 μm have medical and optical communication applications. The diode laser light is focused with a 60-mm focal length lens onto the YLF crystal. A high-reflectivity mirror with 100-mm radius of curvature was used as the output coupler. The lasing threshold was at 5 mWof incident power. This is higher than expected considering that a high reflector was used as the output coupler. However, a more uniform cooling of the crystal is expected to lower the lasing threshold. With 100 mW of pump power coupled into the crystal, --20 mW of 2-μm radiation was observed from this unoptimized setup. The 2-μm laser output is highly sensitive to output coupler alignment, YLF crystal temperature, and pump laser wavelength. The 20% optical conversion efficiency achieved in his preliminary measurements is expected to be improved by better crystal cooling, proper matching of laser wavelength to crystal absorption, variations in the concentration of Ho and sensitizers and use of a proper output coupler. A study of the parameters mentioned above and the effect of crystal temperature on the laser output is under way

  16. Lasers for the SILVA laser isotope separation process

    International Nuclear Information System (INIS)

    Lapierre, Y.

    1997-01-01

    The main principles of the laser isotope separation process for the production of enriched uranium at lower cost, are reviewed and the corresponding optimal laser characteristics are described. The development of the SILVA laser isotope separation process involved researches in the various domains of pump lasers, dye lasers, laser and optics systems and two test facilities for the feasibility studies which are expected for 1997

  17. Development of frequency tunable Ti:sapphire laser and dye laser pumped by a pulsed Nd:YAG laser

    International Nuclear Information System (INIS)

    Yi, Jong Hoon; Horn, Roland; Wendt, K.

    2001-01-01

    We investigated lasing characteristics of two kinds of tunable laser, liquid dye laser and solid Ti:sapphire crystal laser, pumped by high pulse repetition rate Nd:YAG laser. Dye laser showed drastically reduced pulsewidth compared with that of pump laser and it also contained large amount of amplified spontaneous emission. Ti:sapphire laser showed also reduced pulsewidth. But, the laser conversion pump laser and Ti:sapphire laser pulse, we used a Brewster-cut Pockel's cell for Q-switching. The laser was frequency doubled by a type I BBO crystal outside of the cavity.

  18. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  19. Laser power sources and laser technology for accelerators

    International Nuclear Information System (INIS)

    Lowenthal, D.

    1986-01-01

    The requirements on laser power sources for advanced accelerator concepts are formidable. These requirements are driven by the need to deliver 5 TeV particles at luminosities of 10/sup 33/ - 10/sup 34/ cm/sup -2/ sec/sup -1/. Given that optical power can be transferred efficiently to the particles these accelerator parameters translate into single pulse laser output energies of several kilojoules and rep rates of 1-10 kHz. The average laser output power is then 10-20 MW. Larger average powers will be needed if efficient transfer proves not to be possible. A laser plant of this magnitude underscores the importance of high wall plug efficiency and reasonable cost in $/Watt. The interface between the laser output pulse format and the accelerator structure is another area that drives the laser requirements. Laser accelerators break up into two general architectures depending on the strength of the laser coupling. For strong coupling mechanisms, the architecture requires many ''small'' lasers powering the accelerator in a staged arrangement. For the weak coupling mechanisms, the architecture must feature a single large laser system whose power must be transported along the entire accelerator length. Both of these arrangements have demanding optical constraints in terms of phase matching sequential stages, beam combining arrays of laser outputs and optimizing coupling of laser power in a single accelerating stage

  20. Laser pumped lasers for isotope separation

    International Nuclear Information System (INIS)

    Fry, S.M.

    1976-01-01

    A study of the isotope separation laser requirements reveals that high pressure polyatomic molecular gas laser pumped lasers can attain the necessary characteristics including tunability, energy output, pulse width, and repetition rate. The results of a search, made for molecules meeting the appropriate requirements for one of several pump schemes utilizing a CO 2 laser and with output in the 12 μm or 16μm wavelength range, are presented. Several methods of pumping are reviewed and two novel pump schemes are presented. A laser pumped laser device design is given, and operation of this device and associated diagnostic equipment is confirmed by repeating experiments in OCS and NH 3 . The results of OCS laser experiments show that an improvement in pump rate and output per unit length is obtained with the device, using a wedged transverse pumping scheme. A new multi-line laser system in NH 3 pumped by a TEA CO 2 laser is reported. More than forty transitions spanning the wavelength range of 9.2 to 13.8 μm are observed and identified. A strong output at 12.08 μm is one of the closest lines yet found to the required laser isotope separation wavelength. Far infrared emission near 65 μm is observed and is responsible for populating levels which lase in pure ammonia near 12.3 μm. Buffer gas (e.g., N 2 or He) pressures of approximately 40--800 torr cause energy transfer by collision-induced rotationaltransitions from the pumped antisymmetric to the lasing symmetric levels in the nu 2 = 1 band of ammonia. Most of the observed lines are aP(J,K) transitions which originate from the nu 2 /sup s/ band. Measurements of the pressure dependence of the laser output shows that some lines lase at pressures greater than one atmosphere. Transient behavior of the 12.08 μm line is calculated from a simplified analytic model and these calculations are compared to the experimental results

  1. Future prospects of laser diodes and fiber lasers

    International Nuclear Information System (INIS)

    Ueda, Ken-ichi

    2000-01-01

    For the next century we should develop new concepts for coherent control of light generation and propagation. Owing to the recent development of ultra fine structures in semiconductor lasers, fiber lasers, and various kinds of waveguide structure, we can make optical devices which control the light propagation artificially. But, the phase locking and phase control of multiple laser oscillators are one of the most important directions of laser science and technology. The coherent summation has been a dream of laser since 1960. Is it possible to solve this old and quite challenging problem for laser science? This is also a very basic concept because the laser action based on the stimulated emission is the process of coherent summation of huge number of photons emitted from individual atoms. In this paper, I discuss the fundamental direction of laser research in the next ten or twenty years. The active optics and laser technology should be combined intrinsically in near future. (author)

  2. YCOB lasers

    International Nuclear Information System (INIS)

    Richardson, Martin; Hammons, Dennis; Eichenholz, Jason; Chai, Bruce; Ye, Qing; Jang, Won; Shah, Lawrence

    1999-01-01

    We review new developments with a new laser host material, YCa 4 O(BO 3 ) 3 or YCOB. Lasers based on this host material will open new opportunities for the development of compact, high-power, frequency-agile visible and near IR laser sources, as well as sources for ultrashort pulses. Efficient diode-pumped laser action with both Nd-doped and Yb-doped YCOB has already been demonstrated. Moreover, since these materials are biaxial, and have high nonlinear optical coefficients, they have become the first laser materials available as efficient self-frequency-doubled lasers, capable of providing tunable laser emission in several regions of the visible spectrum. Self-frequency doubling eliminates the need for inclusion of a nonlinear optical element within or external to the laser resonator. These laser materials possess excellent thermal and optical properties, have high laser-damage thresholds, and can be grown to large sizes. In addition they are non-hygroscopic. They therefore possess all the characteristics necessary for laser materials required in rugged, compact systems. Here we summarize the rapid progress made in the development of this new class of lasers, and review their potential for a number of applications. (author)

  3. Parameters in fractional laser assisted delivery of topical anesthetics: Role of laser type and laser settings.

    Science.gov (United States)

    Meesters, Arne A; Nieboer, Marilin J; Kezic, Sanja; de Rie, Menno A; Wolkerstorfer, Albert

    2018-05-07

    Efficacy of topical anesthetics can be enhanced by pretreatment of the skin with ablative fractional lasers. However, little is known about the role of parameters such as laser modality and laser density settings in this technique. Aims of this study were to compare the efficacy of pretreatment with two different ablative fractional laser modalities, a CO 2 laser and an Er:YAG laser, and to assess the role of laser density in ablative fractional laser assisted topical anesthesia. In each of 15 healthy subjects, four 10 × 10 mm test regions on the back were randomized to pretreatment (70-75 μm ablation depth) with CO 2 laser at 5% density, CO 2 laser at 15% density, Er:YAG laser at 5% density or Er:YAG laser at 15% density. Articaine hydrochloride 40 mg/ml + epinephrine 10 μg/ml solution was applied under occlusion to all four test regions. After 15 minutes, a pass with the CO 2 laser (1,500 μm ablation depth) was administered as pain stimulus to each test region. A reference pain stimulus was given on unanesthetized skin. The main outcome parameter, pain, was scored on a 0-10 visual analogue scale (VAS) after each pain stimulus. Median VAS scores were 1.50 [CO 2 5%], 0.50 [CO 2 15%], 1.50 [Er:YAG 5%], 0.43 [Er:YAG 15%], and 4.50 [unanesthetized reference]. VAS scores for all pretreated test regions were significantly lower compared to the untreated reference region (P laser pretreated regions. However, VAS scores were significantly lower at 15% density compared to 5% density for both for the CO 2 laser (P laser (P laser was considered slightly more painful than pretreatment with Er:YAG laser by the subjects. Fractional laser assisted topical anesthesia is effective even with very low energy settings and an occlusion time of only 15 minutes. Both the CO 2 laser and the Er:YAG laser can be used to assist topical anesthesia although the CO 2 laser pretreatment is experienced as more painful. In our study settings, using articaine

  4. Laser beam cutting method. Laser ko ni yoru kaitai koho

    Energy Technology Data Exchange (ETDEWEB)

    Kutsumizu, A. (Obayashi Corp., Osaka (Japan))

    1991-07-01

    In this special issue paper concerning the demolition of concrete structures, was introduced a demolition of concrete structures using laser, of which practical application is expected due to the remarkable progress of generating power and efficiency of laser radiator. The characteristics of laser beam which can give a temperature of one million centigrade at the irradiated spot, the laser radiator consisting of laser medium, laser resonator and pumping apparatus, and the laser kinds for working, such as CO{sub 2} laser, YAG laser and CO laser, were described. The basic constitution of laser cutting equipment consisting of large generating power radiator, beam transmitter, beam condenser, and nozzle for working was also illustrated. Furthermore, strong and weak points in the laser cutting for concrete and reinforcement were enumerated. Applications of laser to cutting of reinforced and unreinforced concrete constructions were shown, and the concept and safety measure for application of laser to practical demolition was discussed. 5 refs., 8 figs.

  5. Ultrashort pulse laser technology laser sources and applications

    CERN Document Server

    Schrempel, Frank; Dausinger, Friedrich

    2016-01-01

    Ultrashort laser pulses with durations in the femtosecond range up to a few picoseconds provide a unique method for precise materials processing or medical applications. Paired with the recent developments in ultrashort pulse lasers, this technology is finding its way into various application fields. The book gives a comprehensive overview of the principles and applications of ultrashort pulse lasers, especially applied to medicine and production technology. Recent advances in laser technology are discussed in detail. This covers the development of reliable and cheap low power laser sources as well as high average power ultrashort pulse lasers for large scale manufacturing. The fundamentals of laser-matter-interaction as well as processing strategies and the required system technology are discussed for these laser sources with respect to precise materials processing. Finally, different applications within medicine, measurement technology or materials processing are highlighted.

  6. Laser beam diagnostics for kilowatt power pulsed YAG laser

    International Nuclear Information System (INIS)

    Liu, Yi; Leong, Keng H.

    1992-01-01

    There is a growing need for high power YAG laser beam diagnostics with the recent introduction of such lasers in laser material processing. In this paper, we will describe the use of a commercially available laser beam analyzer (Prometec) to profile the laser beam from a 1600 W pulsed Nd:YAG laser that has a 1 mm fiber optic beam delivery system. The selection of laser pulse frequency and pulse width for the measurement is discussed. Laser beam propagation parameters by various optical components such as fibers and lenses can be determined from measurements using this device. The importance of such measurements will be discussed

  7. Laser materials processing with diode lasers

    OpenAIRE

    Li, Lin; Lawrence, Jonathan; Spencer, Julian T.

    1996-01-01

    Laser materials processing is currently dominated by CO2, Nd-YAG and Excimer lasers. Continuous advances in semiconductor laser technology over the last decade have increased the average power output of the devices annualy by two fold, resulting in the commercial availability of the diode lasers today with delivery output powers in excess of 60W in CW mode and 5kW in qasi-CW mode. The advantages of compactness, high reliability, high efficiency and potential low cost, due to the mass producti...

  8. Transurethral vaporesection of prostate: diode laser or thulium laser?

    Science.gov (United States)

    Tan, Xinji; Zhang, Xiaobo; Li, Dongjie; Chen, Xiong; Dai, Yuanqing; Gu, Jie; Chen, Mingquan; Hu, Sheng; Bai, Yao; Ning, Yu

    2018-05-01

    This study compared the safety and effectiveness of the diode laser and thulium laser during prostate transurethral vaporesection for treating benign prostate hyperplasia (BPH). We retrospectively analyzed 205 patients with BPH who underwent a diode laser or thulium laser technique for prostate transurethral vaporesection from June 2016 to June 2017 and who were followed up for 3 months. Baseline characteristics of the patients, perioperative data, postoperative outcomes, and complications were compared. We also assessed the International Prostate Symptom Score (IPSS), quality of life (QoL), maximum flow rate (Q max ), average flow rate (AFR), and postvoid residual volume (PVR) at 1 and 3 months postoperatively to evaluate the functional improvement of each group. There were no significant differences between the diode laser and thulium laser groups related to age, prostate volume, operative time, postoperative hospital stays, hospitalization costs, or perioperative data. The catheterization time was 3.5 ± 0.8 days for the diode laser group and 4.7 ± 1.8 days for the thulium laser group (p diode laser and thulium laser contributes to safe, effective transurethral vaporesection in patients with symptomatic BPH. Diode laser, however, is better than thulium laser for prostate transurethral vaporesection because of its shorter catheterization time. The choice of surgical approach is more important than the choice of laser types during clinical decision making for transurethral laser prostatectomy.

  9. Reverse spontaneous laser line sweeping in ytterbium fiber laser

    Czech Academy of Sciences Publication Activity Database

    Navrátil, Petr; Peterka, Pavel; Honzátko, Pavel; Kubeček, V.

    2017-01-01

    Roč. 14, č. 3 (2017), č. článku 035102. ISSN 1612-2011 R&D Projects: GA ČR(CZ) GA16-13306S Institutional support: RVO:67985882 ; RVO:68378271 Keywords : laser line sweeping * ytterbium * fiber lasers Subject RIV: BH - Optics, Masers, Lasers; BH - Optics, Masers, Lasers (FZU-D) OBOR OECD: Optics (including laser optics and quantum optics); Optics (including laser optics and quantum optics) (FZU-D) Impact factor: 2.537, year: 2016

  10. High-energy molecular lasers self-controlled volume-discharge lasers and applications

    CERN Document Server

    Apollonov, V V

    2016-01-01

    This book displays the physics and design of high-power molecular lasers. The lasers described are self-controlled volume-discharge lasers. The book explains self-sustained discharge lasers, self-initiated discharge lasers and technical approaches to laser design. Important topics discussed are laser efficiency, laser beam quality and electric field homogeneity. The book contains many new innovative applications.

  11. Laser safety considerations for a mobile laser program

    Science.gov (United States)

    Flor, Mary

    1997-05-01

    An increased demand for advanced laser technology, especially in the area of cutaneous and cosmetic procedures has prompted physicians to use mobile laser services. Utilization of a mobile laser service allows physicians to provide the latest treatments for their patients while minimizing overhead costs. The high capital expense of laser systems is often beyond the financial means of individual clinicians, group practices, free-standing clinics and smaller community hospitals. Historically rapid technology turnover with laser technology places additional risk which is unacceptable to many institutions. In addition, health care reform is mandating consolidation of equipment within health care groups to keep costs at a minimum. In 1994, Abbott Northwestern Hospital organized an in-house mobile laser technology service which employs a group of experienced laser specialists to deliver and support laser treatments for hospital outreach and other regional physicians and health care facilities. Many of the hospital's internal safety standards and policies are applicable to the mobile environment. A significant challenge is client compliance because of the delicate balance of managing risk while avoiding being viewed as a regulator. The clinics and hospitals are assessed prior to service to assure minimum laser safety standards for both the patient and the staff. A major component in assessing new sites is to inform them of applicable regulatory standards and their obligations to assure optimum laser safety. In service training is provided and hospital and procedures are freely shared to assist the client in establishing a safe laser environment. Physician and nursing preceptor programs are also made available.

  12. PISA-undersøgelsen - kan den bruges til noget?

    DEFF Research Database (Denmark)

    Lindenskov, Lena; Jankvist, Uffe Thomas; Fink, Klaus

    2014-01-01

    Der gives beskrivelser af det indhold i PISA-rapporterne, som kan betyde noget for, hvordan matematiklærere og didaktikere kan handle. Med fokus på PISA 2012 gengives 4 matematik-spørgsmål, hovedresultater fra elevbesvarelser af opgaver og spørgeskemaer samt forklaringer og nye didaktiske spørgsm....... Der sammenlignes også kort med TIMSS 2011....

  13. Dermatological laser treatment

    International Nuclear Information System (INIS)

    Moerk, N.J.; Austad, J.; Helland, S.; Thune, P.; Volden, G.; Falk, E.

    1991-01-01

    The article reviews the different lasers used in dermatology. Special emphasis is placed on the treatment of naevus flammeus (''portwine stain'') where lasers are the treatment of choice. Argon laser and pulsed dye laser are the main lasers used in vascular skin diseases, and the article focuses on these two types. Copper-vapour laser, neodymium-YAG laser and CO 2 laser are also presented. Information is provided about the availability of laser technology in the different health regions in Norway. 5 refs., 2 figs

  14. Laser Ablation of Biological Tissue Using Pulsed CO2 Laser

    International Nuclear Information System (INIS)

    Hashishin, Yuichi; Sano, Shu; Nakayama, Takeyoshi

    2010-01-01

    Laser scalpels are currently used as a form of laser treatment. However, their ablation mechanism has not been clarified because laser excision of biological tissue occurs over a short time scale. Biological tissue ablation generates sound (laser-induced sound). This study seeks to clarify the ablation mechanism. The state of the gelatin ablation was determined using a high-speed video camera and the power reduction of a He-Ne laser beam. The aim of this study was to clarify the laser ablation mechanism by observing laser excision using the high-speed video camera and monitoring the power reduction of the He-Ne laser beam. We simulated laser excision of a biological tissue by irradiating gelatin (10 wt%) with radiation from a pulsed CO 2 laser (wavelength: 10.6 μm; pulse width: 80 ns). In addition, a microphone was used to measure the laser-induced sound. The first pulse caused ablation particles to be emitted in all directions; these particles were subsequently damped so that they formed a mushroom cloud. Furthermore, water was initially evaporated by laser irradiation and then tissue was ejected.

  15. Laser applications in nanotechnology: nanofabrication using laser ablation and laser nanolithography

    International Nuclear Information System (INIS)

    Makarov, G N

    2013-01-01

    The fact that nanoparticles and nanomaterials have fundamental properties different both from their constituent atoms or molecules and from their bulk counterparts has stimulated great interest, both theoretical and practical, in nanoparticles and nanoparticle-based assemblies (functional materials), with the result that these structures have become the subject of explosive research over the last twenty years or so. A great deal of progress in this field has relied on the use of lasers. In this paper, the directions followed and results obtained in laser nanotechnology research are reviewed. The parameters, properties, and applications of nanoparticles are discussed, along with the physical and chemical methods for their fabrication and investigation. Nanofabrication applications of and fundamental physical principles behind laser ablation and laser nanolithography are discussed in detail. The applications of laser radiation are shown to range from fabricating, melting, and evaporating nanoparticles to changing their shape, structure, size, and size distribution, through studying their dynamics and forming them into periodic arrays and various structures and assemblies. The historical development of research on nanoparticles and nanomaterials and the application of laser nanotechnology in various fields are briefly reviewed. (reviews of topical problems)

  16. Laser spectroscopy and laser isotope separation of atomic gadolinium

    International Nuclear Information System (INIS)

    Chen, Y. W.; Yamanaka, C.; Nomaru, K.; Kou, K.; Niki, H.; Izawa, Y.; Nakai, S.

    1994-01-01

    Atomic vapor laser isotope separation (AVLIS) is a process which uses intense pulsed lasers to selectively photoionize one isotopic species of a chemical element, after which these ions are extracted electromagnetically. The AVLIS has several advantages over the traditional methods based on the mass difference, such as high selectivity, low energy consumption, short starting time and versatility to any atoms. The efforts for atomic vapor laser isotope separation at ILT and ILE, Osaka University have been concentrated into the following items: 1) studies on laser spectroscopy and laser isotope separation of atomic gadolinium, 2) studies on interaction processes including coherent dynamics, propagation effects and atom-ion collision in AVLIS system, 3) development of laser systems for AVLIS. In this paper, we present experimental results on the laser spectroscopy and laser isotope separation of atomic gadolinium.

  17. The Newest Laser Processing

    International Nuclear Information System (INIS)

    Lee, Baek Yeon

    2007-01-01

    This book mentions laser processing with laser principle, laser history, laser beam property, laser kinds, foundation of laser processing such as laser oscillation, characteristic of laser processing, laser for processing and its characteristic, processing of laser hole including conception of processing of laser hole and each material, and hole processing of metal material, cut of laser, reality of cut, laser welding, laser surface hardening, application case of special processing and safety measurement of laser.

  18. Electrodeless excimer laser; Laser a eccimeri senza elettrodi

    Energy Technology Data Exchange (ETDEWEB)

    Lisi, N. [ENEA, Divisione Nuovi Materiali, Centro Ricerche Casaccia, Rome (Italy)

    2001-07-01

    In this paper it is proposed how to build an excimer laser based on an electrodeless discharge (or Dielectric Barrier Discharge). Such laser could operate with a low energy per pulse (<100 mJ) and a high repetition rate (<100 kHz). The most relevant advantage an electrodeless DBD laser is the much longer gas mixture lifetime. This feature could allow the operation of a sealed laser emitting higher average power with respect to commercially available excimer lasers. Such discharge scheme could be advantageous in order to excite the F{sub 2} excimer molecule, whose emission wavelength in the VUV range (157 nm) at high reprate is particularly interesting in the micro-lithography field. [Italian] In questo documento viene proposto come costruire un laser a eccimeri basato su una scarica priva di elettrodi, o Dielectric Barrier Discharge. Tale laser puo' funzionare con una bassa energia per impulso (<100 mJ) ad alta frequenza di ripetizione (<100 kHz). Il vantaggio fondamentale di un laser a DBD e quindi privo di elettrodi e' la vita media della miscela gassosa molto piu' alta che potrebbe permettere alla camera laser di operare sigillata ad una potenza media superiore a quella dei laser a eccimeri attuali. Tale schema di pompaggio potrebbe essere particolarmente vantaggioso per eccitare la molecola eccimero F{sub 2} la cui lunghezza di emissione nel VUV (157 nm) ad elevata frequenza di ripetizione presenta un notevole interesse nel campo della produzione di microcircuiti.

  19. Laser technologies for laser accelerators. Annual report

    International Nuclear Information System (INIS)

    1985-01-01

    The primary result of the work reported is the determination of laser system architectures that satsify the requirements of high luminosity, high energy (about 1 TeV), electron accelerators. It has been found that high laser efficiency is a very hard driver for these accelerators as the total average laser output optical power is likely to fall above 10 MW. The luminosity requires rep rates in the kHz range, and individual pulse lengths in the 1-10 psec range are required to satisfy acceleration gradient goals. CO 2 and KrF lasers were chosen for study because of their potential to simultaneously satisfy the given requirements. Accelerator luminosity is reviewed, and requirements on laser system average power and rep rate are determined as a function of electron beam bunch parameters. Laser technologies are reviewed, including CO 2 , excimers, solid state, and free electron lasers. The proposed accelerator mechanisms are summarized briefly. Work on optical transport geometries for near and far field accelerators are presented. Possible exploitation of the CO 2 and DrF laser technology to generate the required pulse lengths, rep rates, and projected efficiencies is illustrated and needed development work is suggested. Initial efforts at developing a 50 GeV benchmark conceptual design and a 100 MeV demonstration experiment conceptual design are presented

  20. Laser ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Bykovskij, Yu

    1979-02-01

    The characteristics a laser source of multiply-ionized ions are described with regard to the interaction of laser radiation and matter, ion energy spectrum, angular ion distribution. The amount of multiple-ionization ions is evaluated. Out of laser source applications a laser injector of multiple-ionization ions and nuclei, laser mass spectrometry, laser X-ray microradiography, and a laser neutron generators are described.

  1. Laser Physics and Physics with Lasers - Recent Advances

    International Nuclear Information System (INIS)

    Marowsky, G.

    2008-01-01

    This contribution reviews the development as well as recent technological advances in the field of optics with lasers and laser-related applications. Topics ranging from 'attoscience' to 'zero-modes' shall be dealt with in this presentation. Further reading in the following references is suggested: Springer Handbook of Lasers and Optics (F. Trager, ed.), 2007, ISBN-13: 978-0-387-95579-7; Chapter 11.7, Part C: Ultraviolet Lasers: Excimers, Fluorine (F2), Nitrogen (N2), pp. 764-776; Excimer Laser Technology (D. Basting, G. Marowsky, eds.) 2005, Springer, ISBN-13 978-3-540-20056-7

  2. LASER PROCESSING ON SINGLE CRYSTALS BY UV PULSE LASER

    OpenAIRE

    龍見, 雅美; 佐々木, 徹; 高山, 恭宜

    2009-01-01

    Laser processing by using UV pulsed laser was carried out on single crystal such as sapphire and diamond in order to understand the fundamental laser processing on single crystal. The absorption edges of diamond and sapphire are longer and shorter than the wave length of UV laser, respectively. The processed regions by laser with near threshold power of processing show quite different state in each crystal.

  3. Design windows of laser fusion power plants and conceptual design of laser-diode pumped slab laser

    International Nuclear Information System (INIS)

    Kozaki, Y.; Eguchi, T.; Izawa, Y.

    1999-01-01

    An analysis of the design space available to laser fusion power plants has been carried out, in terms of design key parameters such as target gain, laser energy and laser repetition rate, the number of fusion react ion chambers, and plant size. The design windows of economically attractive laser fusion plants is identified with the constraints of key design parameters and the cost conditions. Especially, for achieving high repetition rate lasers, we have proposed and designed a diode-pumped solid-state laser driver which consists of water-cooled zig-zag path slab amplifiers. (author)

  4. Lasers

    CERN Document Server

    Milonni, Peter W

    1988-01-01

    A comprehensive introduction to the operating principles and applications of lasers. Explains basic principles, including the necessary elements of classical and quantum physics. Provides concise discussions of various laser types including gas, solid state, semiconductor, and free electron lasers, as well as of laser resonators, diffraction, optical coherence, and many applications including holography, phase conjugation, wave mixing, and nonlinear optics. Incorporates many intuitive explanations and practical examples. Discussions are self-contained in a consistent notation and in a style that should appeal to physicists, chemists, optical scientists and engineers.

  5. Development of laser materials processing and laser metrology techniques

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Chung, Chin Man; Kim, Jeong Mook; Kim, Min Suk; Kim, Kwang Suk; Baik, Sung Hoon; Kim, Seong Ouk; Park, Seung Kyu

    1997-09-01

    The applications of remote laser materials processing and metrology have been investigated in nuclear industry from the beginning of laser invention because they can reduce the risks of workers in the hostile environment by remote operation. The objective of this project is the development of laser material processing and metrology techniques for repairing and inspection to improve the safety of nuclear power plants. As to repairing, we developed our own laser sleeve welding head and innovative optical laser weld monitoring techniques to control the sleeve welding process. Furthermore, we designed and fabricated a 800 W Nd:YAG and a 150 W Excimer laser systems for high power laser materials processing in nuclear industry such as cladding and decontamination. As to inspection, we developed an ESPI and a laser triangulation 3-D profile measurement system for defect detection which can complement ECT and UT inspections. We also developed a scanning laser vibrometer for remote vibration measurement of large structures and tested its performance. (author). 58 refs., 16 tabs., 137 figs

  6. Development of short pulse laser pumped x-ray lasers

    International Nuclear Information System (INIS)

    Dunn, J; Osterheld, A L; Hunter, J R; Shlyaptsev, V N

    2000-01-01

    X-ray lasers have been extensively studied around the world since the first laboratory demonstration on the Novette laser at LLNL in 1984 [l]. The characteristic properties of short wavelength, high monochromaticity, collimation and coherence make x-ray lasers useful for various applications. These include demonstrations of biological imaging within the water window, interferometry of laser plasmas and radiography of laser-heated surfaces. One of the critical issues has been the high power pump required to produce the inversion. The power scaling as a function of x-ray laser wavelength follows a -k4 to law. The shortest x-ray laser wavelength of ∼ 35 (angstrom) demonstrated for Ni-like All was at the limit of Nova laser capabilities. By requiring large, high power lasers such as Nova, the shot rate and total number of shots available have limited the rapid development of x-ray lasers and applications. In fact over the last fifteen years the main thrust has been to develop more efficient, higher repetition rate x-ray lasers that can be readily scaled to shorter wavelengths. The recent state of progress in the field can be found in references. The objective of the project was to develop a soft x-ray laser (XRL) pumped by a short pulse laser of a few joules. In effect to demonstrate a robust, worlung tabletop x-ray laser at LLNL for the first time. The transient collisional scheme as proposed by Shlyaptsev et al [8, 9] was the candidate x-ray laser for study. The successful endeavour of any scientific investigation is often based upon prudent early decisions and the choice of this scheme was both sound and fruitful. It had been demonstrated very recently for Ne-like Ti at 326 A using a small tabletop laser [10] but had not yet reached its full potential. We chose this scheme for several reasons: (a) it was a collisional-type x-ray laser which has been historically the most robust; (b) it had the promise of high efficiency and low energy threshold for lasing; (c) the

  7. Laser-supported detonation waves and pulsed laser propulsion

    International Nuclear Information System (INIS)

    Kare, J.

    1990-01-01

    A laser thermal rocket uses the energy of a large remote laser, possibly ground-based, to heat an inert propellant and generate thrust. Use of a pulsed laser allows the design of extremely simple thrusters with very high performance compared to chemical rockets. The temperatures, pressures, and fluxes involved in such thrusters (10 4 K, 10 2 atmospheres, 10 7 w/cm 2 ) typically result in the creation of laser-supported detonation (LSD) waves. The thrust cycle thus involves a complex set of transient shock phenomena, including laser-surface interactions in the ignition of the LSD wave, laser-plasma interactions in the LSD wave itself, and high-temperature nonequilibrium chemistry behind the LSD wave. The SDIO Laser Propulsion Program is investigating these phenomena as part of an overall effort to develop the technology for a low-cost Earth-to-orbit laser launch system. We will summarize the Program's approach to developing a high performance thruster, the double-pulse planar thruster, and present an overview of some results obtained to date, along with a discussion of the many research question still outstanding in this area

  8. ND:GLASS LASER DESIGN FOR LASER ICF FISSION ENERGY (LIFE)

    International Nuclear Information System (INIS)

    Caird, J.A.; Agrawal, V.; Bayramian, A.; Beach, R.; Britten, J.; Chen, D.; Cross, R.; Ebbers, C.; Erlandson, A.; Feit, M.; Freitas, B.; Ghosh, C.; Haefner, C.; Homoelle, D.; Ladran, T.; Latkowski, J.; Molander, W.; Murray, J.; Rubenchik, S.; Schaffers, K.; Siders, C.W.; Stappaerts, E.; Sutton, S.; Telford, S.; Trenholme, J.; Barty, C.J.

    2008-01-01

    We have developed preliminary conceptual laser system designs for the Laser ICF (Inertial Confinement Fusion) Fission Energy (LIFE) application. Our approach leverages experience in high-energy Nd:glass laser technology developed for the National Ignition Facility (NIF), along with high-energy-class diode-pumped solid-state laser (HEC-DPSSL) technology developed for the DOE's High Average Power Laser (HAPL) Program and embodied in LLNL's Mercury laser system. We present laser system designs suitable for both indirect-drive, hot spot ignition and indirect-drive, fast ignition targets. Main amplifiers for both systems use laser-diode-pumped Nd:glass slabs oriented at Brewster's angle, as in NIF, but the slabs are much thinner to allow for cooling by high-velocity helium gas as in the Mercury laser system. We also describe a plan to mass-produce pump-diode lasers to bring diode costs down to the order of $0.01 per Watt of peak output power, as needed to make the LIFE application economically attractive

  9. Laser fusion

    International Nuclear Information System (INIS)

    Eliezer, S.

    1982-02-01

    In this paper, the physics of laser fusion is described on an elementary level. The irradiated matter consists of a dense inner core surrounded by a less dense plasma corona. The laser radiation is mainly absorbed in the outer periphery of the plasma. The absorbed energy is transported inward to the ablation surface where plasma flow is created. Due to this plasma flow, a sequence of inward going shock waves and heat waves are created, resulting in the compression and heating of the core to high density and temperature. The interaction physics between laser and matter leading to thermonuclear burn is summarized by the following sequence of events: Laser absorption → Energy transport → Compression → Nuclear Fusion. This scenario is shown in particular for a Nd:laser with a wavelength of 1 μm. The wavelength scaling of the physical processes is also discussed. In addition to the laser-plasma physics, the Nd high power pulsed laser is described. We give a very brief description of the oscillator, the amplifiers, the spatial filters, the isolators and the diagnostics involved. Last, but not least, the concept of reactors for laser fusion and the necessary laser system are discussed. (author)

  10. New power lasers

    International Nuclear Information System (INIS)

    Yamanaka, Masanobu; Daido, Hiroyuki; Imasaki, Kazuo.

    1989-01-01

    As the new power lasers which are expected to exert large extending effect to the fields of advanced science and technology including precision engineering as well as laser nuclear fusion, LD-excited solid laser, X-ray laser and free electron laser are taken up and outlined. Recently, the solid laser using high power output, high efficiency semiconductor laser as the exciting beam source has been developed. This is called laser diode (LD)-excited solid laser, and the heightening of power output and efficiency and the extension of life are planned. Its present status and application to medical use, laser machining, laser soldering and so on are described. In 1960, the laser in visible region appeared, however in 1985, the result of observing induced emission beam by electron collision exciting method was reported in USA. In the wavelength range of 200 A, holography and contact X-ray microscope applications were verified. The various types of soft X-ray laser and the perspective hereafter are shown. The principle of free electron laser is explained. In the free electron laser, wavelength can be changed by varying electron beam energy, the period of wiggler magnetic field and the intensity of magnetic field. Further, high efficiency and large power output are possible. Its present status, application and the perspective hereafter are reported. (K.I.)

  11. An application of the theory of laser to nitrogen laser pumped dye laser

    International Nuclear Information System (INIS)

    Osman, Fatima Ahmed

    1998-03-01

    In this thesis we gave a general discussion on lasers, reviewing some of their properties, types and application. We also conducted an experiment where we obtained a dye laser pumped by nitrogen laser with a wave length of 337.1 nm and a power of 5 Mw.It was noticed that the produced radiation possesses characteristics different from those of other types of laser. This characteristics determine the tunability i.e the possibility of choosing the appropriately required wave-length of radiation for various applications.(Author)

  12. Laser propulsion for orbit transfer - Laser technology issues

    Science.gov (United States)

    Horvath, J. C.; Frisbee, R. H.

    1985-01-01

    Using reasonable near-term mission traffic models (1991-2000 being the assumed operational time of the system) and the most current unclassified laser and laser thruster information available, it was found that space-based laser propulsion orbit transfer vehicles (OTVs) can outperform the aerobraked chemical OTV over a 10-year life-cycle. The conservative traffic models used resulted in an optimum laser power of about 1 MW per laser. This is significantly lower than the power levels considered in other studies. Trip time was taken into account only to the extent that the system was sized to accomplish the mission schedule.

  13. Efficiencies of laser dyes for atomic vapor laser isotope separation

    International Nuclear Information System (INIS)

    Maeda, Mitsuo; Oki, Yuji; Uchiumi, Michihiro; Takao, Takayuki; Igarashi, Kaoru; Shimamoto, Kojiro.

    1995-01-01

    Efficiencies of 30 laser dyes for the atomic vapor laser isotope separation (AVLIS) are experimentally evaluated with a dye laser pumped by a frequency-doubled Nd:YAG laser. On the other hand, a simulation code is developed to describe the laser action of Rhodamine 6G, and the dependence of the laser efficiency on the pump wavelength is calculated. Following conclusions are obtained by these considerations:space: 1) Pyrromethene 567 showed 16% higher laser efficiency than Rhodamine 6G by 532 nm pumping, and Pyrromethene 556 has an ability to provide better efficiency by green light pumping with a Cu vapor laser; 2) Kiton red 620 and Rhodamine 640, whose efficiencies were almost the same as Rhodamine 6G by 532 nm pumping, will show better efficiencies by two-wavelength pumping with a Cu vapor laser. (author)

  14. Laser frequency modulator for modulating a laser cavity

    Science.gov (United States)

    Erbert, Gaylen V.

    1992-01-01

    The present invention relates to a laser frequency modulator for modulating a laser cavity. It is known in the prior art to utilize a PZT (piezoelectric transducer) element in combination with a mirror to change the cavity length of a laser cavity (which changes the laser frequency). Using a PZT element to drive the mirror directly is adequate at frequencies below 10 kHz. However, in high frequency applications (100 kHz and higher) PZT elements alone do not provide a sufficient change in the cavity length. The present invention utilizes an ultrasonic concentrator with a PZT element and mirror to provide modulation of the laser cavity. With an ultrasonic concentrator, the mirror element at the end of a laser cavity can move at larger amplitudes and higher frequencies.

  15. Laser Technology.

    Science.gov (United States)

    Gauger, Robert

    1993-01-01

    Describes lasers and indicates that learning about laser technology and creating laser technology activities are among the teacher enhancement processes needed to strengthen technology education. (JOW)

  16. ND:GLASS LASER DESIGN FOR LASER ICF FISSION ENERGY (LIFE)

    Energy Technology Data Exchange (ETDEWEB)

    Caird, J A; Agrawal, V; Bayramian, A; Beach, R; Britten, J; Chen, D; Cross, R; Ebbers, C; Erlandson, A; Feit, M; Freitas, B; Ghosh, C; Haefner, C; Homoelle, D; Ladran, T; Latkowski, J; Molander, W; Murray, J; Rubenchik, S; Schaffers, K; Siders, C W; Stappaerts, E; Sutton, S; Telford, S; Trenholme, J; Barty, C J

    2008-10-28

    We have developed preliminary conceptual laser system designs for the Laser ICF (Inertial Confinement Fusion) Fission Energy (LIFE) application. Our approach leverages experience in high-energy Nd:glass laser technology developed for the National Ignition Facility (NIF), along with high-energy-class diode-pumped solid-state laser (HEC-DPSSL) technology developed for the DOE's High Average Power Laser (HAPL) Program and embodied in LLNL's Mercury laser system. We present laser system designs suitable for both indirect-drive, hot spot ignition and indirect-drive, fast ignition targets. Main amplifiers for both systems use laser-diode-pumped Nd:glass slabs oriented at Brewster's angle, as in NIF, but the slabs are much thinner to allow for cooling by high-velocity helium gas as in the Mercury laser system. We also describe a plan to mass-produce pump-diode lasers to bring diode costs down to the order of $0.01 per Watt of peak output power, as needed to make the LIFE application economically attractive.

  17. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    International Nuclear Information System (INIS)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-01-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  18. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    Science.gov (United States)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-02-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  19. Excimer Laser Technology

    CERN Document Server

    Basting, Dirk

    2005-01-01

    This comprehensive survey on Excimer Lasers investigates the current range of the technology, applications and devices of this commonly used laser source, as well as the future of new technologies, such as F2 laser technology. Additional chapters on optics, devices and laser systems complete this compact handbook. A must read for laser technology students, process application researchers, engineers or anyone interested in excimer laser technology. An effective and understandable introduction to the current and future status of excimer laser technology.

  20. Laser systems for on-line laser ion sources

    International Nuclear Information System (INIS)

    Geppert, Christopher

    2008-01-01

    Since its initiation in the middle of the 1980s, the resonant ionization laser ion source has been established as a reliable and efficient on-line ion source for radioactive ion beams. In comparison to other on-line ion sources it comprises the advantages of high versatility for the elements to be ionized and of high selectivity and purity for the ion beam generated by resonant laser radiation. Dye laser systems have been the predominant and pioneering working horses for laser ion source applications up to recently, but the development of all-solid-state titanium:sapphire laser systems has nowadays initiated a significant evolution within this field. In this paper an overview of the ongoing developments will be given, which have contributed to the establishment of a number of new laser ion source facilities worldwide during the last five years.

  1. Histologic evaluation of laser lipolysis: pulsed 1064-nm Nd:YAG laser versus cw 980-nm diode laser.

    Science.gov (United States)

    Mordon, Serge; Eymard-Maurin, Anne Françoise; Wassmer, Benjamin; Ringot, Jean

    2007-01-01

    The use of the laser as an auxiliary tool has refined the traditional technique for lipoplasty. During laser lipolysis, the interaction between the laser and the fat produced direct cellular destruction before the suction, reduced bleeding, and promoted skin tightening. This study sought to perform a comparative histologic evaluation of laser lipolysis with the pulsed 1064-nm Nd:YAG laser versus a continuous 980-nm diode laser. A pulsed 1064-nm Nd:YAG (Smart-Lipo; Deka, Italy) and a CW 980-nm diode laser (Pharaon, Osyris, France) were evaluated at different energy settings for lipolysis on the thighs of a fresh cadaver. The lasers were coupled to a 600-microm optical fiber inserted in a 1-mm diameter cannula. Biopsy specimens were taken on irradiated and non-irradiated areas. Hematoxylin-erythrosin-safran staining and immunostaining (anti-PS100 polyclonal antibody) were performed to identify fat tissue damage. In the absence of laser exposures (control specimens), cavities created by cannulation were seen; adipocytes were round in appearance and not deflated. At low energy settings, tumescent adipocytes were observed. At higher energy settings, cytoplasmic retraction, disruption of membranes, and heat-coagulated collagen fibers were noted; coagulated blood cells were also present. For the highest energy settings, carbonization of fat tissue involving fibers and membranes was clearly seen. For equivalent energy settings, 1064-nm and 980-nm wavelengths gave similar histologic results. Laser lipolysis is a relatively new technique that is still under development. Our histologic findings suggest several positive benefits of the laser, including skin retraction and a reduction in intraoperative bleeding. The interaction of the laser with the tissue is similar at 980 nm and 1064 nm with the same energy settings. Because higher volumes of fat are removed with higher total energy, a high-power 980-nm diode laser could offer an interesting alternative to the 1064-nm Nd

  2. Tapered diode laser pumped 946 nm Nd:YAG laser

    DEFF Research Database (Denmark)

    Cheng, Haynes Pak Hay; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2009-01-01

    We successfully implemented a 946 nm Nd:YAG laser based on a 808 nm tapered diode pump laser. The tapered diode is developed at the Ferdinand-Braun-Institute fur Hochstfrequenztechnik in Germany. Figure 2 shows the experimental setup and results of each pump source coupled into a 1.5 mm crystal...... laser, we show that tapered diode laser pumping potentially increase the power of 946 nm lasers by a factor of two and reduce the threshold by a factor of three....

  3. High power lasers & systems

    OpenAIRE

    Chatwin, Chris; Young, Rupert; Birch, Philip

    2015-01-01

    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  4. Spectroscopic and imaging diagnostics of pulsed laser deposition laser plasmas

    International Nuclear Information System (INIS)

    Thareja, Raj K.

    2002-01-01

    An overview of laser spectroscopic techniques used in the diagnostics of laser ablated plumes used for thin film deposition is given. An emerging laser spectroscopic imaging technique for the laser ablation material processing is discussed. (author)

  5. Laser-diode pumped 40-W Yb:YAG ceramic laser.

    Science.gov (United States)

    Hao, Qiang; Li, Wenxue; Pan, Haifeng; Zhang, Xiaoyi; Jiang, Benxue; Pan, Yubai; Zeng, Heping

    2009-09-28

    We demonstrated a high-power continuous-wave (CW) polycrystalline Yb:YAG ceramic laser pumped by fiber-pigtailed laser diode at 968 nm with 400 mum fiber core. The Yb:YAG ceramic laser performance was compared for different Yb(3+) ion concentrations in the ceramics by using a conventional end-pump laser cavity consisting of two flat mirrors with output couplers of different transmissions. A CW laser output of 40 W average power with M(2) factor of 5.8 was obtained with 5 mol% Yb concentration under 120 W incident pump power. This is to the best of our knowledge the highest output power in end-pumped bulk Yb:YAG ceramic laser.

  6. Ceramic Laser Materials

    Directory of Open Access Journals (Sweden)

    Guillermo Villalobos

    2012-02-01

    Full Text Available Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements.

  7. Infrared laser system

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Carbone, R.J.

    1977-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture

  8. Ceramic Laser Materials

    Science.gov (United States)

    Sanghera, Jasbinder; Kim, Woohong; Villalobos, Guillermo; Shaw, Brandon; Baker, Colin; Frantz, Jesse; Sadowski, Bryan; Aggarwal, Ishwar

    2012-01-01

    Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG) ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements. PMID:28817044

  9. Laser cutting: industrial relevance, process optimization, and laser safety

    Science.gov (United States)

    Haferkamp, Heinz; Goede, Martin; von Busse, Alexander; Thuerk, Oliver

    1998-09-01

    Compared to other technological relevant laser machining processes, up to now laser cutting is the application most frequently used. With respect to the large amount of possible fields of application and the variety of different materials that can be machined, this technology has reached a stable position within the world market of material processing. Reachable machining quality for laser beam cutting is influenced by various laser and process parameters. Process integrated quality techniques have to be applied to ensure high-quality products and a cost effective use of the laser manufacturing plant. Therefore, rugged and versatile online process monitoring techniques at an affordable price would be desirable. Methods for the characterization of single plant components (e.g. laser source and optical path) have to be substituted by an omnivalent control system, capable of process data acquisition and analysis as well as the automatic adaptation of machining and laser parameters to changes in process and ambient conditions. At the Laser Zentrum Hannover eV, locally highly resolved thermographic measurements of the temperature distribution within the processing zone using cost effective measuring devices are performed. Characteristic values for cutting quality and plunge control as well as for the optimization of the surface roughness at the cutting edges can be deducted from the spatial distribution of the temperature field and the measured temperature gradients. Main influencing parameters on the temperature characteristic within the cutting zone are the laser beam intensity and pulse duration in pulse operation mode. For continuous operation mode, the temperature distribution is mainly determined by the laser output power related to the cutting velocity. With higher cutting velocities temperatures at the cutting front increase, reaching their maximum at the optimum cutting velocity. Here absorption of the incident laser radiation is drastically increased due to

  10. Laser wakefield acceleration with high-power, few-cycle mid-IR lasers

    OpenAIRE

    Papp, Daniel; Wood, Jonathan C.; Gruson, Vincent; Bionta, Mina; Gruse, Jan-Niclas; Cormier, Eric; Najmudin, Zulfikar; Légaré, François; Kamperidis, Christos

    2018-01-01

    The study of laser wakefield electron acceleration (LWFA) using mid-IR laser drivers is a promising path for future laser driven electronaccelerators, when compared to traditional near-IR laser drivers uperating at 0.8-1 {\\mu}m central wavelength ({\\lambda}laser), as the necessary vector potential a_0 for electron injection can be achieved with smaller laser powers due to the linear dependence on {\\lambda}laser. In this work, we perform 2D PIC simulations on LWFA using few-cycle high power (5...

  11. Laser requirements for a laser fusion energy power plant

    Institute of Scientific and Technical Information of China (English)

    Stephen; E.Bodner; Andrew; J.Schmitt; John; D.Sethian

    2013-01-01

    We will review some of the requirements for a laser that would be used with a laser fusion energy power plant, including frequency, spatial beam smoothing, bandwidth, temporal pulse shaping, efficiency, repetition rate, and reliability. The lowest risk and optimum approach uses a krypton fluoride gas laser. A diode-pumped solid-state laser is a possible contender.

  12. LaserFest Celebration

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Alan Chodos; Elizabeth A. Rogan

    2011-08-25

    LaserFest was the yearlong celebration, during 2010, of the 50th anniversary of the demonstration of the first working laser. The goals of LaserFest were: to highlight the impact of the laser in its manifold commercial, industrial and medical applications, and as a tool for ongoing scientific research; to use the laser as one example that illustrates, more generally, the route from scientific innovation to technological application; to use the laser as a vehicle for outreach, to stimulate interest among students and the public in aspects of physical science; to recognize and honor the pioneers who developed the laser and its many applications; to increase awareness among policymakers of the importance of R&D funding as evidenced by such technology as lasers. One way in which LaserFest sought to meet its goals was to encourage relevant activities at a local level all across the country -- and also abroad -- that would be identified with the larger purposes of the celebration and would carry the LaserFest name. Organizers were encouraged to record and advertise these events through a continually updated web-based calendar. Four projects were explicitly detailed in the proposals: 1) LaserFest on the Road; 2) Videos; 3) Educational material; and 4) Laser Days.

  13. Development of high-power CO2 lasers and laser material processing

    Science.gov (United States)

    Nath, Ashish K.; Choudhary, Praveen; Kumar, Manoj; Kaul, R.

    2000-02-01

    Scaling laws to determine the physical dimensions of the active medium and optical resonator parameters for designing convective cooled CO2 lasers have been established. High power CW CO2 lasers upto 5 kW output power and a high repetition rate TEA CO2 laser of 500 Hz and 500 W average power incorporated with a novel scheme for uniform UV pre- ionization have been developed for material processing applications. Technical viability of laser processing of several engineering components, for example laser surface hardening of fine teeth of files, laser welding of martensitic steel shroud and titanium alloy under-strap of turbine, laser cladding of Ni super-alloy with stellite for refurbishing turbine blades were established using these lasers. Laser alloying of pre-placed SiC coating on different types of aluminum alloy, commercially pure titanium and Ti-6Al-4V alloy, and laser curing of thermosetting powder coating have been also studied. Development of these lasers and results of some of the processing studies are briefly presented here.

  14. Laser plasma instability experiments with KrF lasers

    International Nuclear Information System (INIS)

    Weaver, J. L.; Karasik, M.; Serlin, V.; Obenschain, S.; Chan, L-Y.; Kehne, D.; Schmitt, A. J.; Colombant, D.; Velikovich, A.; Oh, J.; Lehmberg, R. H.; Afeyan, B.; Phillips, L.; Seely, J.; Brown, C.; Feldman, U.; Aglitskiy, Y.; Mostovych, A. N.; Holland, G.

    2007-01-01

    Deleterious effects of laser-plasma instability (LPI) may limit the maximum laser irradiation that can be used for inertial confinement fusion. The short wavelength (248 nm), large bandwidth, and very uniform illumination available with krypton-fluoride (KrF) lasers should increase the maximum usable intensity by suppressing LPI. The concomitant increase in ablation pressure would allow implosion of low-aspect-ratio pellets to ignition with substantial gain (>20) at much reduced laser energy. The proposed KrF-laser-based Fusion Test Facility (FTF) would exploit this strategy to achieve significant fusion power (150 MW) with a rep-rate system that has a per pulse laser energy well below 1 MJ. Measurements of LPI using the Nike KrF laser are presented at and above intensities needed for the FTF (I∼2x10 15 W/cm 2 ). The results to date indicate that LPI is indeed suppressed. With overlapped beam intensity above the planar, single beam intensity threshold for the two-plasmon decay instability, no evidence of instability was observed via measurements of (3/2)ω o and (1/2)ω o harmonic emissions

  15. Physics of laser fusion. Volume III. High-power pulsed lasers

    International Nuclear Information System (INIS)

    Holzrichter, J.F.; Eimerl, D.; George, E.V.; Trenholme, J.B.; Simmons, W.W.; Hunt, J.T.

    1982-09-01

    High-power pulsed lasers can deliver sufficient energy on inertial-confinement fusion (ICF) time scales (0.1 to 10 ns) to heat and compress deuterium-tritium fuel to fusion-reaction conditions. Several laser systems have been examined, including Nd:glass, CO 2 , KrF, and I 2 , for their ICF applicability. A great deal of developmental effort has been applied to the Nd:glass laser and the CO 2 gas laser systems; these systems now deliver > 10 4 J and 20 x 10 12 W to ICF targets. We are constructing the Nova Nd:glass laser at LLNL to provide > 100 kJ and > 100 x 10 12 W of 1-μm radiation for fusion experimentation in the mid-1980s. For ICF target gain > 100 times the laser input, we expect that the laser driver must deliver approx. 3 to 5 MJ of energy on a time scale of 10 to 20 ns. In this paper we review the technological status of fusion-laser systems and outline approaches to constructing high-power pulsed laser drivers

  16. Raman fiber lasers

    CERN Document Server

    2017-01-01

    This book serves as a comprehensive, up-to-date reference about this cutting-edge laser technology and its many new and interesting developments. Various aspects and trends of Raman fiber lasers are described in detail by experts in their fields. Raman fiber lasers have progressed quickly in the past decade, and have emerged as a versatile laser technology for generating high power light sources covering a spectral range from visible to mid-infrared. The technology is already being applied in the fields of telecommunication, astronomy, cold atom physics, laser spectroscopy, environmental sensing, and laser medicine. This book covers various topics relating to Raman fiber laser research, including power scaling, cladding and diode pumping, cascade Raman shifting, single frequency operation and power amplification, mid-infrared laser generation, specialty optical fibers, and random distributed feedback Raman fiber lasers. The book will appeal to scientists, students, and technicians seeking to understand the re...

  17. Effect of laser spot size on energy balance in laser induced plasmas

    International Nuclear Information System (INIS)

    Pant, H.C.; Sharma, S.; Bhawalkar, D.D.

    1980-01-01

    The effect of the laser spot size on laser light absorption in laser induced plasmas from solid targets was studied. It was found that at a constant laser intensity on the target, reduction in the laser spot size enhances the net laser energy absorption. It was also observed that the laser light reflection from the target becomes more diffused when the focal spot size is reduced

  18. Influence of laser parameters on laser ultrasonic efficiency

    CSIR Research Space (South Africa)

    Forbes, A

    2007-01-01

    Full Text Available , TEA CO2 lasers, laser chemistry, short pulses 1. INTRODUCTION Polymer-matrix composites are increasingly used in the aerospace industry, particularly in the manufacture of modern fighter planes1-3. The number and complexity of such composites... efficiency can be improved by utilising short pulses in the 3–4 µm and 10 µm spectral regions1. Short pulse 10 µm radiation can be produced by transversely excited, atmospheric CO2 (TEA CO2) lasers. Due to the technological maturity of these lasers...

  19. Improving the laser brightness of a commercial laser system

    Science.gov (United States)

    Naidoo, Darryl; Litvin, Igor; Forbes, Andrew

    2016-02-01

    We investigate the selection of a flat-top beam and a Gaussian beam inside a laser cavity on opposing mirrors. The concept is tested external to the laser cavity in a single pass and double pass regime where the latter mimics a single round trip in the laser. We implement this intra-cavity selection through the use of two 16 level diffractive optical elements. We consider a solid-state diode side-pumped laser resonator in a typical commercial laser configuration that consists of two planar mirrors where the DOEs are positioned at the mirrors. We out couple the Gaussian and flat-top distributions and we show that we improve the brightness of the laser with active mode control. We also demonstrate that the quality of the beam transformations determine the brightness improvement.

  20. Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy.

    Science.gov (United States)

    Kulikov, Alexei N; Maltsev, Dmitrii S; Boiko, Ernest V

    2016-01-01

    Purpose . To compare three 360°-laser retinopexy (LRP) approaches (using navigated pattern laser system, single-spot slit-lamp (SL) laser delivery, and single-spot indirect ophthalmoscope (IO) laser delivery) in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods . Eighty-six rhegmatogenous retinal detachment patients (86 eyes) were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale), number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system), 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients). Results . In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%), 17 (60.7%), and 13 patients (59.1%), respectively ( p > 0.05). Conclusion . The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope) approaches with a single-spot laser.

  1. Practical laser safety

    International Nuclear Information System (INIS)

    Winburn, D.C.

    1985-01-01

    This book includes discussions of the following topics: characteristics of lasers; eye components; skin damage thresholds; classification of lasers by ANSI Z136.1; selecting laser-protective eyewear; hazards associated with lasers; and, an index

  2. Lasers technology

    International Nuclear Information System (INIS)

    2014-01-01

    The Laser Technology Program of IPEN is developed by the Center for Lasers and Applications (CLA) and is committed to the development of new lasers based on the research of new optical materials and new resonator technologies. Laser applications and research occur within several areas such as Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. Additional goals of the Program are human resource development and innovation, in association with Brazilian Universities and commercial partners

  3. LASERS: A cryogenic slab CO laser

    Science.gov (United States)

    Ionin, Andrei A.; Kozlov, A. Yu; Seleznev, L. V.; Sinitsyn, D. V.

    2009-03-01

    A compact capacitive transverse RF-discharge-pumped slab CO laser with cryogenically cooled electrodes, which operates both in the cw and repetitively pulsed regimes, is fabricated. The laser operation is studied in the free running multifrequency regime at the vibrational - rotational transitions of the fundamental (V + 1 → V) vibrational bands of the CO molecule in the spectral region from 5.1 to 5.4 μm. Optimal operation conditions (gas mixture composition and pressure, RF pump parameters) are determined. It is shown that only gas mixtures with a high content of oxygen (up to 20% with respect to the concentration of CO molecules) can be used as an active medium of this laser. It is demonstrated that repetitively pulsed pumping is more efficient compared to cw pumping. In this case, quasi-cw lasing regime can be obtained. The maximum average output power of ~12 W was obtained for this laser operating on fundamental bands and its efficiency achieved ~14 %. The frequency-selective operation regime of the slab RF-discharge-pumped CO laser was realised at ~ 100 laser lines in the spectral region from 5.0 to 6.5 μm with the average output power of up to several tens of milliwatts in each line. Lasing at the transitions of the first vibrational overtone (V + 2 → V) of the CO molecule is obtained in the spectral region from 2.5 to 3.9 μm. The average output power of the overtone laser achieved 0.3 W. All the results were obtained without the forced gas mixture exchange in the discharge chamber. Under fixed experimental conditions, repetitively pulsed lasing (with fluctuations of the output characteristics no more than ±10 %) was stable for more than an hour.

  4. Laser Stabilization with Laser Cooled Strontium

    DEFF Research Database (Denmark)

    Christensen, Bjarke Takashi Røjle

    The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting the nonli......The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting...... the nonlinear effects from coupling of an optical cavity to laser cooled atoms having a narrow transition linewidth. Here, we have realized such a system where a thermal sample of laser cooled strontium-88 atoms are coupled to an optical cavity. The strontium-88 atoms were probed on the narrow 1S0-3P1 inter......-combination line at 689 nm in a strongly saturated regime. The dynamics of the atomic induced phase shift and absorption of the probe light were experimentally studied in details with the purpose of applications to laser stabilization. The atomic sample temperature was in the mK range which brought this system out...

  5. Measurements of laser parameters for the Shiva laser fusion facility

    International Nuclear Information System (INIS)

    Ozarski, R.G.

    1979-01-01

    Large laser systems require numerous laser diagnostics to provide configuration, performance and maintenance data to permit efficient operation. The following diagnostics for a large laser system named Shiva are discussed: (1) description of Shiva laser system, (2) what measurements are desired and or required and why, (3) what measurement techniques and packages are employed and a brief description of the operating principles of the sensors employed, and (4) the laser diagnostic data acquisition and display system

  6. Laser beam-plasma plume interaction during laser welding

    Science.gov (United States)

    Hoffman, Jacek; Moscicki, Tomasz; Szymanski, Zygmunt

    2003-10-01

    Laser welding process is unstable because the keyhole wall performs oscillations which results in the oscillations of plasma plume over the keyhole mouth. The characteristic frequencies are equal to 0.5-4 kHz. Since plasma plume absorbs and refracts laser radiation, plasma oscillations modulate the laser beam before it reaches the workpiece. In this work temporary electron densities and temperatures are determined in the peaks of plasma bursts during welding with a continuous wave CO2 laser. It has been found that during strong bursts the plasma plume over the keyhole consists of metal vapour only, being not diluted by the shielding gas. As expected the values of electron density are about two times higher in peaks than their time-averaged values. Since the plasma absorption coefficient scales as ~N2e/T3/2 (for CO2 laser radiation) the results show that the power of the laser beam reaching the metal surface is modulated by the plasma plume oscillations. The attenuation factor equals 4-6% of the laser power but it is expected that it is doubled by the refraction effect. The results, together with the analysis of the colour pictures from streak camera, allow also interpretation of the dynamics of the plasma plume.

  7. Para-hydrogen raman laser and its application to laser induced chemistry

    International Nuclear Information System (INIS)

    Tashiro, Hideo

    1988-01-01

    The report outlines the mechanism of the para-hydrogen Raman laser as a infrared light source, and its application to laser induced chemistry. The Stoke's wave number after a Raman shift is equal to the difference between the wave number of the CO 2 laser used for excitation and the rotation Raman wave number of the hydrogen molecule. A Raman laser can serve as an infrared source. CO 2 laser oscillation beam in the range of 9∼11 micrometers is selected and the frequency of infrared beam is varied by changing the wave number of the CO 2 laser beam. A problem with the Raman laser is that the Raman scatterring gain is small due to a large wavelength. In developing equipment, a special mechanism is required to solve this problem. A Raman laser comprises a CO 2 laser for excitation and multi-pulse Raman cells. The combination of a TEA oscillator and amplifiers gives CO 2 pulses with a peak power of about several tens of MW. Many heavy metal compounds including fluorides, carbonyl compounds and other organic compounds, absorb light with wavelengths in the same range as those of the Raman laser. Such compounds can be dissociated directly by applying Raman laser beams. The laser will be helpful for separation of isotopes, etc. (Nogami, K.)

  8. Laser material processing

    CERN Document Server

    Steen, William

    2010-01-01

    This text moves from the basics of laser physics to detailed treatments of all major materials processing techniques for which lasers are now essential. New chapters cover laser physics, drilling, micro- and nanomanufacturing and biomedical laser processing.

  9. Lasers in space

    Science.gov (United States)

    Michaelis, M. M.; Forbes, A.; Bingham, R.; Kellett, B. J.; Mathye, A.

    2008-05-01

    A variety of laser applications in space, past, present, future and far future are reviewed together with the contributions of some of the scientists and engineers involved, especially those that happen to have South African connections. Historically, two of the earliest laser applications in space, were atmospheric LIDAR and lunar ranging. These applications involved atmospheric physicists, several astronauts and many of the staff recruited into the Soviet and North American lunar exploration programmes. There is a strong interest in South Africa in both LIDAR and lunar ranging. Shortly after the birth of the laser (and even just prior) theoretical work on photonic propulsion and space propulsion by laser ablation was initiated by Georgii Marx, Arthur Kantrowitz and Eugen Saenger. Present or near future experimental programs are developing in the following fields: laser ablation propulsion, possibly coupled with rail gun or gas gun propulsion; interplanetary laser transmission; laser altimetry; gravity wave detection by space based Michelson interferometry; the de-orbiting of space debris by high power lasers; atom laser interferometry in space. Far future applications of laser-photonic space-propulsion were also pioneered by Carl Sagan and Robert Forward. They envisaged means of putting Saenger's ideas into practice. Forward also invented a laser based method for manufacturing solid antimatter or SANTIM, well before the ongoing experiments at CERN with anti-hydrogen production and laser-trapping. SANTIM would be an ideal propellant for interstellar missions if it could be manufactured in sufficient quantities. It would be equally useful as a power source for the transmission of information over light year distances. We briefly mention military lasers. Last but not least, we address naturally occurring lasers in space and pose the question: "did the Big Bang lase?"

  10. Frequency-doubled diode laser for direct pumping of Ti:sapphire lasers

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Unterhuber, Angelika

    2012-01-01

    . However, the superior electro-optical efficiency of the diode laser improves the overall efficiency of the Ti:sapphire laser by a factor > 2. The optical spectrum emitted by the Ti:sapphire laser shows a spectral width of 112 nm (FWHM). Based on autocorrelation measurements, pulse widths of less than 20...... fs are measured. These results open the opportunity of establishing diode laser pumped Ti:sapphire lasers for e.g. biophotonic applications like retinal optical coherence tomography or pumping of photonic crystal fibers for CARS microscopy.......A single-pass frequency doubled high-power tapered diode laser emitting nearly 1.3 W of green light suitable for direct pumping of Ti:sapphire lasers generating ultrashort pulses is demonstrated. The pump efficiencies reached 75 % of the values achieved with a commercial solid-state pump laser...

  11. Excimer laser applications

    International Nuclear Information System (INIS)

    Fantoni, R.

    1988-01-01

    This lecture deals with laser induced material photoprocessing, especially concerning those processes which are initiated by u.v. lasers (mostly excimer laser). Advantages of using the u.v. radiation emitted by excimer lasers, both in photophysical and photochemical processes of different materials, are discussed in detail. Applications concerning microelectronics are stressed with respect to other applications in different fields (organic chemistry, medicine). As further applications of excimer lasers, main spectroscopic techniques for ''on line'' diagnostics which employ excimer pumped dye lasers, emitting tunable radiation in the visible and near u.v. are reviewed

  12. Technological laser application

    International Nuclear Information System (INIS)

    Shia, D.O.; Kollen, R.; Rods, U.

    1980-01-01

    Problems of the technological applications of lasers are stated in the popular form. Main requirements to a technological laser as well as problems arising in designing any system using lasers have been considered. Areas of the laser applications are described generally: laser treatment of materials, thermal treatment, welding, broach and drilling of holes, scribing, microtreatment and adjustment of resistors, material cutting, investigations into controlled thermonuclear fussion

  13. Effects of laser fluence on silicon modification by four-beam laser interference

    International Nuclear Information System (INIS)

    Zhao, Le; Li, Dayou; Wang, Zuobin; Yue, Yong; Zhang, Jinjin; Yu, Miao; Li, Siwei

    2015-01-01

    This paper discusses the effects of laser fluence on silicon modification by four-beam laser interference. In this work, four-beam laser interference was used to pattern single crystal silicon wafers for the fabrication of surface structures, and the number of laser pulses was applied to the process in air. By controlling the parameters of laser irradiation, different shapes of silicon structures were fabricated. The results were obtained with the single laser fluence of 354 mJ/cm 2 , 495 mJ/cm 2 , and 637 mJ/cm 2 , the pulse repetition rate of 10 Hz, the laser exposure pulses of 30, 100, and 300, the laser wavelength of 1064 nm, and the pulse duration of 7–9 ns. The effects of the heat transfer and the radiation of laser interference plasma on silicon wafer surfaces were investigated. The equations of heat flow and radiation effects of laser plasma of interfering patterns in a four-beam laser interference distribution were proposed to describe their impacts on silicon wafer surfaces. The experimental results have shown that the laser fluence has to be properly selected for the fabrication of well-defined surface structures in a four-beam laser interference process. Laser interference patterns can directly fabricate different shape structures for their corresponding applications

  14. Laser innovated manufacturing technology; Laser ga seisan gijutsu wo kakushinshita

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, I. [Honda Motor Co. Ltd., Tokyo (Japan)

    1996-11-01

    This paper looks back the history of applications of laser processing in the automobile industry, and introduces contents of some particularly unique applications from among them. The CO2 laser and YAG laser that are used mainly have increased their outputs with the times, and 50-kW CO2 laser and 4-kW YAG laser have now become available commercially. The laser processing has become used widely for cutting purpose in Japan, which is in contrast with their high application to welding in Europe and America. Cutting thick plates has been developed recently, which is applicable to plates as thick as about 25 mm. A flexible system in which YAG laser is combined with an optical fiber/articulated robot is operating for three-dimensional shape processing. Automobile makers are adopting laser processing for welding in place of the electron beam welding that has been used conventionally. The process is used also for a number of other applications including surface reformation, such as surface quenching for cylinder liner, and valve seat padding. 8 refs., 8 figs.

  15. The Mercury Laser Advances Laser Technology for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Ebbers, C A; Caird, J; Moses, E

    2009-01-21

    The National Ignition Facility (NIF) at Lawrence Livermore Laboratory is on target to demonstrate 'breakeven' - creating as much fusion-energy output as laser-energy input. NIF will compress a tiny sphere of hydrogen isotopes with 1.8 MJ of laser light in a 20-ns pulse, packing the isotopes so tightly that they fuse together, producing helium nuclei and releasing energy in the form of energetic particles. The achievement of breakeven will culminate an enormous effort by thousands of scientists and engineers, not only at Livermore but around the world, during the past several decades. But what about the day after NIF achieves breakeven? NIF is a world-class engineering research facility, but if laser fusion is ever to generate power for civilian consumption, the laser will have to deliver pulses nearly 100,000 times faster than NIF - a rate of perhaps 10 shots per second as opposed to NIF's several shots a day. The Mercury laser (named after the Roman messenger god) is intended to lead the way to a 10-shots-per-second, electrically-efficient, driver laser for commercial laser fusion. While the Mercury laser will generate only a small fraction of the peak power of NIF (1/30,000), Mercury operates at higher average power. The design of Mercury takes full advantage of the technology advances manifest in its behemoth cousin (Table 1). One significant difference is that, unlike the flashlamp-pumped NIF, Mercury is pumped by highly efficient laser diodes. Mercury is a prototype laser capable of scaling in aperture and energy to a NIF-like beamline, with greater electrical efficiency, while still running at a repetition rate 100,000 times greater.

  16. Laser program overview

    International Nuclear Information System (INIS)

    Storm, E.; Coleman, L.W.

    1985-01-01

    The objectives of the Lawrence Livermore National Laboratory Laser Fusion program are to understand and develop the science and technology of inertial confinement fusion (ICF), and to utilize ICF in short- and long-term military applications, and, in the long-term, as a candidate for central-station civilian power generation. In 1984, using the Novette laser system, the authors completed experiments showing the very favorable scaling of laser-plama interactions with short-wavelength laser light. Their Novette experiments have unequivocally shown that short laser wavelength, i.e., less than 1 μm, is required to provide the drive necessary for efficient compression, ignition, and burn of DT fusion fuel. In other experiments with Novette, the authors made the first unambiguous observation of amplified spontaneous emission in the soft x-ray regime. The authors also conducted military applications and weapons physics experiments, which they discuss in detail in the classified volume of our Laser Program Annual Report. In the second thrust, advanced laser studies, they develop and test the concepts, components, and materials for present and future laser systems. Over the years, this has meant providing the technology base and scientific advances necessary to construct and operate a succession of six evermore-powerful laser systems. The latest of these, Nova, a 100-TW/100-kJ-class laser system, was completed in 1984. The Nd:glass laser continues to be the most effective and versatile tool for ICF and weapons physics because of its scalability in energy, the ability to efficiently convert its 1=μm output to shorter wavelengths, its ability to provide flexible, controlled pulse shaping, and its capability to adapt to a variety of irradiation and focusing geometries. For these reasons, many of our advanced laser studies are in areas appropriate to solid state laser technologies

  17. Power balancing of multibeam laser fusion lasers

    International Nuclear Information System (INIS)

    Seka, W.; Morse, S.; Letzring, S.; Kremens, R.; Kessler, T.J.; Jaanimagi, P.; Keck, R.; Verdon, C.; Brown, D.

    1989-01-01

    The success of laser fusion depends to a good degree on the ability to compress the target to very high densities of ≥1000 times liquid DT. To achieve such compressions require that the irradiation nonuniformity must not exceed ∼1% rms over the whole time of the compression, particularly during the early phases of irradiation. The stringent requirements for the irradiation uniformity for laser fusion have been known for quite some time but until recently the energy balance was mistakenly equated to power balance. The authors describe their effort on energy balance and irradiation patterns on the target. They significantly improved the laser performance with respect to overall intensity distributions on target including the implementation of distributed (random) phase plates in each high power beam. However, the slightly varying performance of the third harmonic conversion crystals in the twenty-four beams of their laser system was generally compensated for by appropriately adjusted 1.054μm input laser energy. Computational analysis of the results of the recent high density campaign are shown

  18. Biocavity Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Gourley, P.L.; Gourley, M.F.

    2000-10-05

    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  19. An overview of the laser ranging method of space laser altimeter

    Science.gov (United States)

    Zhou, Hui; Chen, Yuwei; Hyyppä, Juha; Li, Song

    2017-11-01

    Space laser altimeter is an active remote sensing instrument to measure topographic map of Earth, Moon and planetary. The space laser altimeter determines the range between the instrument and laser footprint by measuring round trip time of laser pulse. The return pulse reflected from ground surface is gathered by the receiver of space laser altimeter, the pulsewidth and amplitude of which are changeable with the variability of the ground relief. Meantime, several kinds of noise overlapped on the return pulse signal affect its signal-to-noise ratio. To eliminate the influence of these factors that cause range walk and range uncertainty, the reliable laser ranging methods need to be implemented to obtain high-precision range results. Based on typical space laser altimeters in the past few decades, various ranging methods are expounded in detail according to the operational principle of instruments and timing method. By illustrating the concrete procedure of determining time of flight of laser pulse, this overview provides the comparison of the employed technologies in previous and undergoing research programs and prospect innovative technology for space laser altimeters in future.

  20. Novel laterally pumped by prism laser configuration for compact solid-state lasers

    International Nuclear Information System (INIS)

    Dascalu, T; Salamu, G; Sandu, O; Voicu, F; Pavel, N

    2013-01-01

    We propose a new laser configuration in which the pump radiation is coupled into the laser crystal through a prism. The laser medium is square shaped and the prism is attached on one of its lateral sides, near one of the crystal extremities. The diode-laser fiber end is placed close to the prism hypotenuse, the pump radiation is coupled into the laser crystal through the opposite surface of the prism and propagates into the crystal through total internal reflections. This laser geometry is simple to align and permits the realization of compact diode-pumped laser systems, as well as power scaling. A diode-pumped Nd:YAG laser yielding pulses of 2.1 mJ energy under a pump with pulses of 9.9 mJ is demonstrated. The laser slope efficiency is 0.22. Furthermore, this geometry enables one to obtain passively Q-switched lasers with the saturable absorber crystal placed between the resonator high-reflectivity mirror and the laser crystal. A Nd:YAG laser, passively Q-switched by a Cr 4+ :YAG crystal with initial transmission T 0 = 0.90, delivering laser output with a pulsed energy of 93 μJ, a duration of 26 ns and a pump threshold of 1.9 mJ, is realized in order to prove the concept. (letter)

  1. A Laser Technology Test Facility for Laser Inertial Fusion Energy (LIFE)

    International Nuclear Information System (INIS)

    Bayramian, A.J.; Campbell, R.W.; Ebbers, C.A.; Freitas, B.L.; Latkowski, J.; Molander, W.A.; Sutton, S.B.; Telford, S.; Caird, J.A.

    2010-01-01

    A LIFE laser driver needs to be designed and operated which meets the rigorous requirements of the NIF laser system while operating at high average power, and operate for a lifetime of >30 years. Ignition on NIF will serve to demonstrate laser driver functionality, operation of the Mercury laser system at LLNL demonstrates the ability of a diode-pumped solid-state laser to run at high average power, but the operational lifetime >30 yrs remains to be proven. A Laser Technology test Facility (LTF) has been designed to specifically address this issue. The LTF is a 100-Hz diode-pumped solid-state laser system intended for accelerated testing of the diodes, gain media, optics, frequency converters and final optics, providing system statistics for billion shot class tests. These statistics will be utilized for material and technology development as well as economic and reliability models for LIFE laser drivers.

  2. Robot-laser system

    International Nuclear Information System (INIS)

    Akeel, H.A.

    1987-01-01

    A robot-laser system is described for providing a laser beam at a desired location, the system comprising: a laser beam source; a robot including a plurality of movable parts including a hollow robot arm having a central axis along which the laser source directs the laser beam; at least one mirror for reflecting the laser beam from the source to the desired location, the mirror being mounted within the robot arm to move therewith and relative thereto to about a transverse axis that extends angularly to the central axis of the robot arm; and an automatic programmable control system for automatically moving the mirror about the transverse axis relative to and in synchronization with movement of the robot arm to thereby direct the laser beam to the desired location as the arm is moved

  3. Development of a compact vertical-cavity surface-emitting laser end-pumped actively Q-switched laser for laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuo; Chen, Rongzhang; Nelsen, Bryan; Chen, Kevin, E-mail: pec9@pitt.edu [Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Liu, Lei; Huang, Xi; Lu, Yongfeng [Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

    2016-03-15

    This paper reports the development of a compact and portable actively Q-switched Nd:YAG laser and its applications in laser-induced breakdown spectroscopy (LIBS). The laser was end-pumped by a vertical-cavity surface-emitting laser (VCSEL). The cavity lases at a wavelength of 1064 nm and produced pulses of 16 ns with a maximum pulse energy of 12.9 mJ. The laser exhibits a reliable performance in terms of pulse-to-pulse stability and timing jitter. The LIBS experiments were carried out using this laser on NIST standard alloy samples. Shot-to-shot LIBS signal stability, crater profile, time evolution of emission spectra, plasma electron density and temperature, and limits of detection were studied and reported in this paper. The test results demonstrate that the VCSEL-pumped solid-state laser is an effective and compact laser tool for laser remote sensing applications.

  4. Laser in urology

    International Nuclear Information System (INIS)

    Breisland, H.O.

    1991-01-01

    The neodymium YAG laser is particularly suited for endoscopic urologic surgery because the YAG laser light can be conducted in flexible fibers. Superficial bladder tumours can be treated under local anaesthesia in the outpatient department. The frequency of local recurrences is low, significantly lower than after electrosection or electrocoagulation. Selected cases of T2-muscle invasive bladder tumours can be cured with laser coagulation applied subsequently to transurethral resection. Combined treatment with electrosection and laser coagulation of localized prostatic cancer is a promising method which compares favourably with results obtained by other treatment modalities. Tumours in the upper urinary tract can be laser-treated through ureteroscopes or nephroscopes, but the treatment should be limited to low stage, low grade tumours. Laser is the treatment of choice for intraurethral condylomatas. Laser treatment of penil carcinoma gives excellent cosmetic and functional results and few local recurrences. Laser lithotripsy is a new technique for treatment of ureteric stones and photodynamic laser therapy is a promising tecnique for treatment of carcinoma in situ in the bladder empithelium. However, neither of these techniques are available for clinical use in Norway as yet. 17 refs., 3 figs., 1 tabs

  5. Laser-induced interactions

    International Nuclear Information System (INIS)

    Green, W.R.

    1979-01-01

    This dissertation discusses some of the new ways that lasers can be used to control the energy flow in a medium. Experimental and theoretical considerations of the laser-induced collision are discussed. The laser-induced collision is a process in which a laser is used to selectively transfer energy from a state in one atomic or molecular species to another state in a different species. The first experimental demonstration of this process is described, along with later experiments in which lasers were used to create collisional cross sections as large as 10 - 13 cm 2 . Laser-induced collisions utilizing both a dipole-dipole interaction and dipole-quadrupole interaction have been experimentally demonstrated. The theoretical aspects of other related processes such as laser-induced spin-exchange, collision induced Raman emission, and laser-induced charge transfer are discussed. Experimental systems that could be used to demonstrate these various processes are presented. An experiment which produced an inversion of the resonance line of an ion by optical pumping of the neutral atom is described. This type of scheme has been proposed as a possible method for constructing VUV and x-ray lasers

  6. Multimegajoule laser project: new compact multipass laser design

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1985-01-01

    A simple laser design that has the fewest laser components of all fusion systems that the authors have studied and that packs closely, thus minimizing space requirements is shown. The Advanced Laser Program objectives are determined by the requirements of the subsystems. The requirements consists of the following elements: high damage thresholds on reflectors; AR layers and dichroic coatings; high-efficiency amplifiers; low-cost production of laser glass, pulse power, and optical elements; and special optical elements, such as an effective phase conjugator and isolator. The combination of a compact architecture and lower-cost, higher-performance components can lead to significant reduction in overall system cost

  7. Laser Propulsion - Quo Vadis

    International Nuclear Information System (INIS)

    Bohn, Willy L.

    2008-01-01

    First, an introductory overview of the different types of laser propulsion techniques will be given and illustrated by some historical examples. Second, laser devices available for basic experiments will be reviewed ranging from low power lasers sources to inertial confinement laser facilities. Subsequently, a status of work will show the impasse in which the laser propulsion community is currently engaged. Revisiting the basic relations leads to new avenues in ablative and direct laser propulsion for ground based and space based applications. Hereby, special attention will be devoted to the impact of emerging ultra-short pulse lasers on the coupling coefficient and specific impulse. In particular, laser sources and laser propulsion techniques will be tested in microgravity environment. A novel approach to debris removal will be discussed with respect to the Satellite Laser Ranging (SRL) facilities. Finally, some non technical issues will be raised aimed at the future prospects of laser propulsion in the international community

  8. Distributed feedback dye laser pumped with copper-vapor laser emission

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, S Yu; Soldatov, A N; Sukhanov, V B

    1983-10-01

    The power-spectrum characteristics of the emission of a distributed feedback dye laser pumped with a copper vapor laser have been studied. Laser action has been observed in five dyes over a tuning range of 530-723 nm with an efficiency of 12.4%. The specfic features of the distributed feedback dye laser operating at pulse repetition rates of 4 kHz are discussed.

  9. Influence of the laser pulse duration on laser-produced plasma properties

    International Nuclear Information System (INIS)

    Drogoff, B Le; Margot, J; Vidal, F; Laville, S; Chaker, M; Sabsabi, M; Johnston, T W; Barthelemy, O

    2004-01-01

    In the framework of laser-induced plasma spectroscopy (LIPS) applications, time-resolved characteristics of laser-produced aluminium plasmas in air at atmospheric pressure are investigated for laser pulse durations ranging from 100 fs to 270 ps. Measurements show that for delays after the laser pulse longer than ∼100 ns, the plasma temperature increases slightly with the laser pulse duration, while the electron density is independent of it. In addition, as the pulse duration increases, the plasma radiation emission lasts longer and the spectral lines arise later from the continuum emission. The time dependence of the continuum emission appears to be similar whatever the duration of the laser pulse is, while the temporal evolution of the line emission seems to be affected mainly by the plasma temperature. Finally, as far as spectrochemical applications (such as LIPS) of laser-produced plasmas are concerned, this study highlights the importance of the choice of appropriate temporal gating parameters for each laser pulse duration

  10. Laser cleaning of pulsed laser deposited rhodium films for fusion diagnostic mirrors

    International Nuclear Information System (INIS)

    Uccello, A.; Maffini, A.; Dellasega, D.; Passoni, M.

    2013-01-01

    Highlights: ► Pulsed laser deposition is exploited to produce Rh films for first mirrors. ► Pulsed laser deposition is exploited to produce tokamak-like C contaminants. ► Rh laser damage threshold has been evaluated for infrared pulses. ► Laser cleaning of C contaminated Rh films gives promising results. -- Abstract: In this paper an experimental investigation on the laser cleaning process of rhodium films, potentially candidates to be used as tokamak first mirrors (FMs), from redeposited carbon contaminants is presented. A relevant issue that lowers mirror's performance during tokamak operations is the redeposition of sputtered material from the first wall on their surface. Among all the possible techniques, laser cleaning, in which a train of laser pulses is launched to the surface that has to be treated, is a method to potentially mitigate this problem. The same laser system (Q-switched Nd:YAG laser with a fundamental wavelength of 1064-nm and 7-ns pulses) has been employed with three aims: (i) production by pulsed laser deposition (PLD) of Rh film mirrors, (ii) production by PLD of C deposits with controlled morphology, and (iii) investigation of the laser cleaning method onto C contaminated Rh samples. The evaluation of Rh films laser damage threshold, as a function of fluence and number of pulses, is discussed. Then, the C/Rh films have been cleaned by the laser beam. The exposed zones have been characterized by visual inspection and scanning electron microscopy (SEM), showing promising results

  11. Attenuation of laser power of a focused Gaussian beam during interaction between a laser and powder in coaxial laser cladding

    International Nuclear Information System (INIS)

    Liu Jichang; Li Lijun; Zhang Yuanzhong; Xie Xiaozhu

    2005-01-01

    The power of a focused laser beam with a Gaussian intensity profile attenuated by powder in coaxial laser cladding is investigated experimentally and theoretically, and its resolution model is developed. With some assumptions, it is concluded that the attenuation of laser power is an exponential function and is determined by the powder feed rate, particle moving speed, spraying angles and waist positions and diameters of the laser beam and powder flow, grain diameter and run of the laser beam through the powder flow. The attenuation of laser power increases with powder feed rate or run of laser beam through the powder flow. In the experiment presented, 300 W laser power from a focused Gaussian beam is attenuated by a coaxial powder flow. The experimental results agree well with the values calculated with the developed model

  12. Tunable laser applications

    CERN Document Server

    Duarte, FJ

    2008-01-01

    Introduction F. J. Duarte Spectroscopic Applications of Tunable Optical Parametric Oscillators B. J. Orr, R. T. White, and Y. He Solid-State Dye Lasers Costela, I. García-Moreno, and R. Sastre Tunable Lasers Based on Dye-Doped Polymer Gain Media Incorporating Homogeneous Distributions of Functional Nanoparticles F. J. Duarte and R. O. James Broadly Tunable External-Cavity Semiconductor Lasers F. J. Duarte Tunable Fiber Lasers T. M. Shay and F. J. Duarte Fiber Laser Overview and Medical Applications

  13. Greco Laser-matter interaction

    International Nuclear Information System (INIS)

    1986-01-01

    Research program in 1985 at GRECO ILM (Group of Coordinated Research: Interaction Laser Matter) continued with its principal direction in fundamental physics of laser inertial confinement; also researches on X-ray lasers hare been undergone and new high power laser application fields with particle acceleration, material processing and X-ray sources. A six beam laser was operated. Wavelength effects were studied. Atomic physics was deeply stressed as dense medium diagnostics from multicharged ions. Research development in ultra-dense medium was also important X-ray laser research gave outstanding results. New research fields were developed this year: laser acceleration of particles by wave beating or Raman instability; dense laser produced plasma use as X-ray source; material processing by laser shocks [fr

  14. Laser applications in materials processing

    International Nuclear Information System (INIS)

    Ready, J.F.

    1980-01-01

    The seminar focused on laser annealing of semiconductors, laser processing of semiconductor devices and formation of coatings and powders, surface modification with lasers, and specialized laser processing methods. Papers were presented on the theoretical analysis of thermal and mass transport during laser annealing, applications of scanning continuous-wave and pulsed lasers in silicon technology, laser techniques in photovoltaic applications, and the synthesis of ceramic powders from laser-heated gas-phase reactants. Other papers included: reflectance changes of metals during laser irradiation, surface-alloying using high-power continuous lasers, laser growth of silicon ribbon, and commercial laser-shock processes

  15. HF laser

    International Nuclear Information System (INIS)

    Suzuki, Kazuya; Iwasaki, Matae

    1977-01-01

    A review is made of the research and development of HF chemical laser and its related work. Many gaseous compounds are used as laser media successfully; reaction kinetics and technological problems are described. The hybrid chemical laser of HF-CO 2 system and the topics related to the isotope separation are also included. (auth.)

  16. Multibeam Fibre Laser Cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre......-laser cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

  17. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber......-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  18. Lasers in periodontics.

    Science.gov (United States)

    Elavarasu, Sugumari; Naveen, Devisree; Thangavelu, Arthiie

    2012-08-01

    Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20(th) century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics.

  19. Laser-driven ion acceleration with hollow laser beams

    International Nuclear Information System (INIS)

    Brabetz, C.; Kester, O.; Busold, S.; Bagnoud, V.; Cowan, T.; Deppert, O.; Jahn, D.; Roth, M.; Schumacher, D.

    2015-01-01

    The laser-driven acceleration of protons from thin foils irradiated by hollow high-intensity laser beams in the regime of target normal sheath acceleration (TNSA) is reported for the first time. The use of hollow beams aims at reducing the initial emission solid angle of the TNSA source, due to a flattening of the electron sheath at the target rear side. The experiments were conducted at the PHELIX laser facility at the GSI Helmholtzzentrum für Schwerionenforschung GmbH with laser intensities in the range from 10 18  W cm −2 to 10 20  W cm −2 . We observed an average reduction of the half opening angle by (3.07±0.42)° or (13.2±2.0)% when the targets have a thickness between 12 μm and 14 μm. In addition, the highest proton energies were achieved with the hollow laser beam in comparison to the typical Gaussian focal spot

  20. Laser-driven ion acceleration with hollow laser beams

    Energy Technology Data Exchange (ETDEWEB)

    Brabetz, C., E-mail: c.brabetz@gsi.de; Kester, O. [Goethe-Universität Frankfurt am Main, 60323 Frankfurt (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Busold, S.; Bagnoud, V. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Jena, 07743 Jena (Germany); Cowan, T. [Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Technische Universität Dresden, 01069 Dresden (Germany); Deppert, O.; Jahn, D.; Roth, M. [Technische Universität Darmstadt, 64277 Darmstadt (Germany); Schumacher, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2015-01-15

    The laser-driven acceleration of protons from thin foils irradiated by hollow high-intensity laser beams in the regime of target normal sheath acceleration (TNSA) is reported for the first time. The use of hollow beams aims at reducing the initial emission solid angle of the TNSA source, due to a flattening of the electron sheath at the target rear side. The experiments were conducted at the PHELIX laser facility at the GSI Helmholtzzentrum für Schwerionenforschung GmbH with laser intensities in the range from 10{sup 18} W cm{sup −2} to 10{sup 20} W cm{sup −2}. We observed an average reduction of the half opening angle by (3.07±0.42)° or (13.2±2.0)% when the targets have a thickness between 12 μm and 14 μm. In addition, the highest proton energies were achieved with the hollow laser beam in comparison to the typical Gaussian focal spot.

  1. High-power pulsed lasers

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1980-01-01

    The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization

  2. Advanced lasers for fusion

    International Nuclear Information System (INIS)

    Krupke, W.F.; George, E.V.; Haas, R.A.

    1979-01-01

    Laser drive systems' performance requirements for fusion reactors are developed following a review of the principles of inertial confinement fusion and of the technical status of fusion research lasers (Nd:glass; CO 2 , iodine). These requirements are analyzed in the context of energy-storing laser media with respect to laser systems design issues: optical damage and breakdown, medium excitation, parasitics and superfluorescence depumping, energy extraction physics, medium optical quality, and gas flow. Three types of energy-storing laser media of potential utility are identified and singled out for detailed review: (1) Group VI atomic lasers, (2) rare earth solid state hybrid lasers, and (3) rare earth molecular vapor lasers. The use of highly-radiative laser media, particularly the rare-gas monohalide excimers, are discussed in the context of short pulse fusion applications. The concept of backward wave Raman pulse compression is considered as an attractive technique for this purpose. The basic physics and device parameters of these four laser systems are reviewed and conceptual designs for high energy laser systems are presented. Preliminary estimates for systems efficiencies are given. (Auth.)

  3. Only lasers can be used for low level laser therapy.

    Science.gov (United States)

    Moskvin, Sergey Vladimirovich

    2017-12-01

    The question of lasers' exclusivity, as well as the degree of influence of special properties of low-intensity laser illumination (LILI), such as coherence, polarity and monochromaticity, on the effectiveness of low level laser therapy (LLLT) continues to cause arguments. The study analyzes publications from 1973 to 2016, in which laser and conventional light sources are compared, and the following conclusions are drawn. First, there are a lot of publications with incorrect comparison or unfounded statements. Secondly, other sources of light are often meant by LILI without any justification. Thirdly, all studies, in which the comparison is carried out correctly and close parameters of the impact and the model are used, have a firm conclusion that laser light is much more effective. Fourthly, it is uniquely identified that the most important parameter that determines the efficiency of lasers is monochromaticity, i.e., a much narrower spectral width than for all other light sources. Only laser light sources can be used for LLLT! © Author(s) 2017. This article is published with open access by China Medical University.

  4. Laser Research Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Laser Research lab is thecenter for the development of new laser sources, nonlinear optical materials, frequency conversion processes and laser-based sensors for...

  5. Amplificación del Segundo Armónico Mediante el Uso de un Cristal Fotónico Amplificación del Segundo Armónico Mediante el Uso de un Cristal Fotónico

    Directory of Open Access Journals (Sweden)

    G. Cerda-Villicaña

    2012-02-01

    Full Text Available Presentamos evidencia experimental de la generación y amplificación de un haz de segundo armónico en una guía de onda plana de niobato de litio mediante la inscripción de un cristal fotónico unidimensional en dicha guía de onda. La observación fue realizada utilizando un láser de Neodimio-YAG (Nd:YAG en modo continuo (cw así como en amarre de modos, obteniendo pulsos con una potencia promedio por debajo del orden de nanojoules (10-9 J y con duración de 150 picosegundos (10-12 seg. La dispersión geométrica introducida por la estructura de bandas fotónica (PGB para los modos de la guía de onda a la frecuencia fundamental y doblada mejora las condiciones de empalme de fase y por lo tanto aumenta la eficiencia de conversión. We present experimental evidence of enhanced second harmonic generation in planar lithiumniobate waveguides by using a photonic crystal on the waveguide. The enhanced signal was observed by using a Nd: YAG pump laser in both continuous mode (c. w. and mode-locked. This last produced sub-nanojoules (10-9 J average power pulses with 150 picoseconds (10-12 s time duration. Phase matching conditions and the conversion efficiency process were improved because of the geometrical dispersion introduced in waveguide modes inside of the photonic band gap structure (PBG at fundamental and second harmonic frequencies.

  6. Laser Cutting of Thick Diamond Films Using Low-Power Laser

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y.J.; Baik, Y.J. [Korea Institute of Science and Technology, Seoul (Korea)

    2000-02-01

    Laser cutting of thick diamond films is studied rising a low-power(10 W) copper vapor laser. Due to the existence of the saturation depth in laser cutting, thick diamond films are not easily cut by low-power lasers. In this study, we have adopted a low thermal- conductivity underlayer of alumina and a heating stage (up to 500 deg. C in air) to prevent the laser energy from consuming-out and, in turn, enhance the cutting efficiency. Aspect ratio increases twice from 3.5 to 7 when the alumina underlayer used. Adopting a heating stage also increases aspect ratio and more than 10 is obtained at higher temperatures than 400 deg. C. These results show that thick diamond films can be cut, with low-power lasers, simply by modifying the thermal property of underlayer. (author). 13 refs., 5 figs.

  7. Laser solenoid: an alternate use of lasers in fusion power

    International Nuclear Information System (INIS)

    Rose, P.H.

    1977-01-01

    A unique laser assisted fusion approach is under development at Mathematical Sciences Northwest, Inc. (MSNW). This approach captures one of the most developed aspects of high energy laser technology, the efficient, large, scalable, pulsed electron beam initiated, electric discharge, CO 2 infrared laser. This advanced technology is then combined with the simple geometry of a linear magnetic confinement system. The laser solenoid concept will be described, current work and experimental progress will be discussed, and the technological problems of building such a system will be assessed. Finally a comparison will be made of the technology and economics for the laser solenoid and alternative fusion approaches

  8. Organic solid-state lasers

    CERN Document Server

    Forget, Sébastien

    2013-01-01

    Organic lasers are broadly tunable coherent sources, potentially compact, convenient and manufactured at low-costs. Appeared in the mid 60’s as solid-state alternatives for liquid dye lasers, they recently gained a new dimension after the demonstration of organic semiconductor lasers in the 90's. More recently, new perspectives appeared at the nanoscale, with organic polariton and surface plasmon lasers. After a brief reminder to laser physics, a first chapter exposes what makes organic solid-state organic lasers specific. The laser architectures used in organic lasers are then reviewed, with a state-of-the-art review of the performances of devices with regard to output power, threshold, lifetime, beam quality etc. A survey of the recent trends in the field is given, highlighting the latest developments with a special focus on the challenges remaining for achieving direct electrical pumping of organic semiconductor lasers. A last chapter covers the applications of organic solid-state lasers.

  9. Quantum well lasers

    CERN Document Server

    Zory, Jr, Peter S; Kelley, Paul

    1993-01-01

    This book provides the information necessary for the reader to achieve a thorough understanding of all aspects of QW lasers - from the basic mechanism of optical gain, through the current technolgoical state of the art, to the future technologies of quantum wires and quantum dots. In view of the growing importance of QW lasers, this book should be read by all those with an active interest in laser science and technology, from the advanced student to the experienced laser scientist.* The first comprehensive book-length treatment of quantum well lasers* Provides a detailed treatment

  10. Lasers in space.

    CSIR Research Space (South Africa)

    Michaelis, MM

    2008-04-01

    Full Text Available cube, laser beam reflectors, placed on the Moon half a century ago. These early achievements will soon be followed by a plethora of experiments involving lasers in low earth orbit (LEO) or at Lagrange points. And not much later, laser communications... will stretch out as far as Mars and beyond. One important low Earth orbit (LEO) application is the removal of space debris by Earth based or LEO relayed lasers as promoted by Phipps et al.3. Another is military communication. The prominent L1 laser space...

  11. Bleaching Dengan Teknologi Laser

    OpenAIRE

    Eliwaty

    2008-01-01

    Penulisan tentang bleaching dengan laser dimaksudkan untuk menambah wawasan serta pengetahuan dari pembaca di bidang kedokteran gigi. Macam-macam laser yang dipergunakan dalam bleaching yaitu argon, CO2 serta dioda laser. Contoh merek produk laser yaitu Blulaze, Dentcure untuk argonlaser, Novapulse untuk C02 serta Opus 5 untuk dioda laser. Laser bleaching hasilnya dapat dicapai dalam satu kunjungan saja, cepat, efisien namun biayanya relatif mahal, dapat menimbulkan burn, sensitivitas se...

  12. Diode-pumped solid state laser. (Part V). ; Short pulse laser oscillation. Handotai laser reiki kotai laser. 5. ; Tan pulse hasshin

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, M.; Bando, N. (Asahi Glass Co. Ltd., Tokyo (Japan))

    1991-12-25

    A semiconductor laser (LD) excited solid state laser using an LD as an excited light source is under discussion for its practical applications to measurements, processing, communications, office automation, and medical areas. This paper describes the discussions given on the short pulse transmission using AOQ switching elements in the LD excited solid state laser with a long wave length band (1.3{mu}m), which is expected of its application in the communications and measurements area. Based on a possibility of raising a measurements resolution by making the pluses in the LD excited solid state laser, and experiments were performed using Nd:YLF as a laser host. as a results, it was found that the smaller the effective mode volume V {sub eff},the smaller the pulse width, and that the ratio of number of initial inversion distribution (N{sub i}/N{sub t}), an important parameter to determine pulse widths, can be obtained from the ratio of the LD exciting light to the input power (P{sub in}/P{sub t}). 7 refs., 14 figs., 2 tabs.

  13. Wavelength sweepable laser source

    DEFF Research Database (Denmark)

    2014-01-01

    Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines...... and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position.; The laser source further comprises electrical...... connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed....

  14. Mathematical modeling of a photovoltaic-laser energy converter for iodine laser radiation

    Science.gov (United States)

    Walker, Gilbert H.; Heinbockel, John H.

    1987-01-01

    Space-based laser power systems will require converters to change laser radiation into electricity. Vertical junction photovoltaic converters are promising devices for this use. A promising laser for the laser power station is the t-C4F9I laser which emits radiation at a wavelength of 1.315 microns. This paper describes the results of mathematical modeling of a photovoltaic-laser energy converter for use with this laser. The material for this photovoltaic converter is Ga(53)In(47)As which has a bandgap energy of 0.94 eV, slightly below the energy of the laser photons (0.943 eV). Results of a study optimizing the converter parameters are presented. Calculated efficiency for a 1000 vertical junction converter is 42.5 percent at a power density of 1 x 10 to the 3d power w/sq cm.

  15. Laser Materials and Laser Spectroscopy - A Satellite Meeting of IQEC '88

    Science.gov (United States)

    Wang, Zhijiang; Zhang, Zhiming

    1989-03-01

    The Table of Contents for the book is as follows: * Laser Materials * Laser Site Spectroscopy of Transition Metal Ions in Glass * Spectroscopy of Chromium Doped Tunable Laser Materials * Spectroscopic Properties of Nd3+ Ions in LaMgAl11O19 Crystal * Spectral Study and 2.938 μm Laser Emission of Er3+ in the Y3Al5O12 Crystal * Raman-infrared Spectra and Radiationless Relaxation of Laser Crystal NdAl3(BO3)4 * A Study on HB and FLN in BaFCl0.5Br0.5:Sm2+ at 77K * Pair-pumped Upconversion Solid State Lasers * CW Upconversion Laser Action in Neodymium and Erbium doped Solids * Ultra-high Sensitive Upconversion Fluorescence of YbF3 Doped with Trace Tm3+ and Er3+ * The Growth and Properties of NYAB and EYAB Multifunctional Crystal * Study on Fluorescence and Laser Light of Er3+ in Glass * Growth and Properties of Single Crystal Fibers for Laser Materials * A Study on the Quality of Sapphire, Ruby and Ti3+ Doped Sapphire Grown by Temperature Gradient Technique (TGT) and Czochralski Technique (CZ) * The Measurement of Output Property of Ti3+ Al2O3 Laser Crystal * An Xα Study of the Laser Crystal MgF2 : V2+ * Q-switched NAB Laser * Miniature YAG Lasers * Study of High Efficiency {LiF}:{F}^-_2 Color Center Crystals * Study on the Formation Conditions and Optical Properties of (F2+)H Color Center in NaCl:OH- Crystals * Novel Spectroscopic Properties of {LiF}:{F}^+_3 - {F}_2 Mixed Color Centers Laser Crystals * Terraced Substrate Visible GaAlAs Semiconductor Lasers with a Large Optical Cavity * The Temperature Dependence of Gain Spectra, Threshold Current and Auger Recombination in InGaAsP-InP Double Heterojunction Laser diode * Time-resolved Photoluminescence and Energy Transfer of Bound Excitons in GaP:N Crystals * Optical Limiting with Semiconductors * A Critical Review of High-efficiency Crystals for Tunable Lasers * Parametric Scattering in β - BaB2O4 Crystal Induced by Picosecond Pulses * Generation of Picosecond Pulses at 193 nm by Frequency Mixing in β - BaB2O4

  16. Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance

    International Nuclear Information System (INIS)

    Li, S.; Alverson, S.; Bohler, D.; Egger, A.; Fry, A.

    2017-01-01

    The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ultraviolet, a wavelength where direct laser manipulation becomes challenging. In this paper, we present a novel application of a digital micromirror device (DMD) for the 253 nm drive laser at the Linear Coherent Light Source. Laser profile shaping is accomplished through an iterative algorithm that takes into account shaping error and efficiency. Next, we use laser shaping to control the X-ray laser output via an online optimizer, which shows improvement in FEL pulse energy. Lastly, as a preparation for electron beam shaping, we use the DMD to measure the photocathode quantum efficiency across cathode surface with an averaged laser rms spot size of 59 μm. In conclusion, our experiments demonstrate promising outlook of using DMD to shape ultraviolet lasers for photocathode rf guns with various applications.

  17. Ultraviolet laser transverse profile shaping for improving x-ray free electron laser performance

    Science.gov (United States)

    Li, S.; Alverson, S.; Bohler, D.; Egger, A.; Fry, A.; Gilevich, S.; Huang, Z.; Miahnahri, A.; Ratner, D.; Robinson, J.; Zhou, F.

    2017-08-01

    The photocathode rf gun is one of the most critical components in x-ray free electron lasers. The drive laser strikes the photocathode surface, which emits electrons with properties that depend on the shape of the drive laser. Most free electron lasers use photocathodes with work function in the ultraviolet, a wavelength where direct laser manipulation becomes challenging. In this paper, we present a novel application of a digital micromirror device (DMD) for the 253 nm drive laser at the Linear Coherent Light Source. Laser profile shaping is accomplished through an iterative algorithm that takes into account shaping error and efficiency. Next, we use laser shaping to control the X-ray laser output via an online optimizer, which shows improvement in FEL pulse energy. Lastly, as a preparation for electron beam shaping, we use the DMD to measure the photocathode quantum efficiency across cathode surface with an averaged laser rms spot size of 59 μ m . Our experiments demonstrate promising outlook of using DMD to shape ultraviolet lasers for photocathode rf guns with various applications.

  18. Laser sampling

    International Nuclear Information System (INIS)

    Gorbatenko, A A; Revina, E I

    2015-01-01

    The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references

  19. Studies on corrosion protection of laser hybrid welded AISI 316 by laser remelting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Ambat, Rajan; Rasmussen, A.J.

    2005-01-01

    laser surface melting on microstructure and corrosion behaviour of AISI 316L welds. Welding and laser treatment parameters were varied. General corrosion behaviour of the weld and laser treated surface was characterised using a gel visualization test. The local electrochemistry of the weld and laser......Unlike in autogenous laser welding, hybrid laser welding of stainless steel could introduce grain boundary carbides due to low cooling rates. Formation of grain boundary carbides leads to reduced corrosion properties. Studies have initially been carried out on hybrid laser welding and subsequent...... treated surface was investigated using a novel micro electrochemical technique with a tip resolution of ~1 mm. Results show that hybrid laser welding of 316L has increased corrosion susceptibility probably as a result of grain boundary carbide formation. However a suitable post laser treatment could...

  20. Excimer laser decontamination

    Science.gov (United States)

    Sentis, Marc L.; Delaporte, Philippe C.; Marine, Wladimir; Uteza, Olivier P.

    2000-04-01

    The application of excimer laser ablation process to the decontamination of radioactive surfaces is discussed. This technology is very attractive because it allows to efficiently remove the contaminated particles without secondary waste production. To demonstrate the capability of such technology to efficiently decontaminate large area, we studied and developed a prototype which include a XeCl laser, an optical fiber delivery system and an ablated particles collection cell. The main physical processes taking place during UV laser ablation will be explained. The influence of laser wavelength, pulse duration and absorption coefficient of material will be discussed. Special studies have been performed to understand the processes which limit the transmission of high average power excimer laser through optical fiber, and to determine the laser conditions to optimize the value of this transmission. An in-situ spectroscopic analysis of laser ablation plasma allows the real time control of the decontamination. The results obtained for painting or metallic oxides removal from stainless steel surfaces will be presented.

  1. Efficient Ho:YLF laser pumped by a Tm:fiber laser

    CSIR Research Space (South Africa)

    Koen, W

    2013-10-01

    Full Text Available A thulium fiber laser pumped Ho:YLF laser delivering 45.1 W in a near diffraction limited beam when pumped with 84.7 W is demonstrated. The optical-to-optical efficiency of 53 % compares favorably with similar Ho:YAG lasers....

  2. Laser Safety Evaluation of the MILES and Mini MILES Laser Emitting Components; TOPICAL

    International Nuclear Information System (INIS)

    AUGUSTONI, ARNOLD L.

    2002-01-01

    Laser safety evaluation and output emission measurements were performed (during October and November 2001) on SNL MILES and Mini MILES laser emitting components. The purpose, to verify that these components, not only meet the Class 1 (eye safe) laser hazard criteria of the CDRH Compliance Guide for Laser Products and 21 CFR 1040 Laser Product Performance Standard; but also meet the more stringent ANSI Std. z136.1-2000 Safe Use of Lasers conditions for Class 1 lasers that govern SNL laser operations. The results of these measurements confirmed that all of the Small Arms Laser Transmitters, as currently set (''as is''), meet the Class 1 criteria. Several of the Mini MILES Small Arms Transmitters did not. These were modified and re-tested and now meet the Class 1 laser hazard criteria. All but one System Controllers (hand held and rifle stock) met class 1 criteria for single trigger pulls and all presented Class 3a laser hazard levels if the trigger is held (continuous emission) for more than 5 seconds on a single point target. All units were Class 3a for ''aided'' viewing. These units were modified and re-tested and now meet the Class 1 hazard criteria for both ''aided'' as well as ''unaided'' viewing. All the Claymore Mine laser emitters tested are laser hazard Class 1 for both ''aided'' as well as ''unaided'' viewing

  3. Laser ablation principles and applications

    CERN Document Server

    1994-01-01

    Laser Ablation provides a broad picture of the current understanding of laser ablation and its many applications, from the views of key contributors to the field. Discussed are in detail the electronic processes in laser ablation of semiconductors and insulators, the post-ionization of laser-desorbed biomolecules, Fourier-transform mass spectroscopy, the interaction of laser radiation with organic polymers, laser ablation and optical surface damage, laser desorption/ablation with laser detection, and laser ablation of superconducting thin films.

  4. CO2-laser fusion

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    The basic concept of laser fusion is described, with a set of requirements on the laser system. Systems and applications concepts are presented and discussed. The CO 2 laser's characteristics and advantages for laser fusion are described. Finally, technological issues in the development of CO 2 laser systems for fusion applications are discussed

  5. Laser dynamics of asynchronous rational harmonic mode-locked fiber soliton lasers

    International Nuclear Information System (INIS)

    Jyu, Siao-Shan; Jiang, Guo-Hao; Lai, Yinchieh

    2013-01-01

    Laser dynamics of asynchronous rational harmonic mode-locked (ARHM) fiber soliton lasers are investigated in detail. In particular, based on the unique laser dynamics of asynchronous mode-locking, we have developed a new method for determining the effective active modulation strength in situ for ARHM lasers. By measuring the magnitudes of the slowly oscillating pulse timing position and central frequency, the effective phase modulation strength at the multiplication frequency of rational harmonic mode-locking can be accurately inferred. The method can be a very useful tool for developing ARHM fiber lasers. (paper)

  6. Radiological protection against lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ballereau, P

    1974-04-01

    A brief description of the biological effects of laser beams is followed by a review of the factors involved in eye and skin damage (factors linked with the nature of lasers and those linked with the organ affected) and a discussion of the problems involved in the determination of threshold exposure levels. Preventive measures are recommended, according to the type of laser (high-energy pulse laser, continuous laser, gas laser). No legislation on the subject exists in France or in Europe. Types of lasers marketed, threshold exposure levels for eye and skin, variations of admissible exposure levels according to wavelength, etc. are presented in tabular form. Nomogram for determination of safe distance for direct vision of a laser is included.

  7. Laser-tissue interaction in tattoo removal by q-switched lasers.

    Science.gov (United States)

    Barua, Shyamanta

    2015-01-01

    Q-switched (QS) lasers are widely considered the gold standard for tattoo removal, with excellent clinical results, impressive predictability, and a good safety profile. The generation of giant pulses by the method of Q-switching is responsible for the unique laser-tissue interaction that is seen in tattoo removal by QS lasers. The QS lasers work by impaction and dissolution of the tattoo pigments. Mechanical fragmentation of the tattoo pigments encased in intracellular lamellated organelles followed by their phagocytosis by macrophages is thought to be the major event in the clearance of pigments by QS lasers. A few novel techniques have been tried in recent times to hasten the clearance of tattoo pigments.

  8. Traveling-wave laser-produced-plasma energy source for photoionization laser pumping and lasers incorporating said

    Science.gov (United States)

    Sher, Mark H.; Macklin, John J.; Harris, Stephen E.

    1989-09-26

    A traveling-wave, laser-produced-plasma, energy source used to obtain single-pass gain saturation of a photoionization pumped laser. A cylindrical lens is used to focus a pump laser beam to a long line on a target. Grooves are cut in the target to present a surface near normal to the incident beam and to reduce the area, and hence increase the intensity and efficiency, of plasma formation.

  9. 5W intracavity frequency-doubled green laser for laser projection

    Science.gov (United States)

    Yan, Boxia; Bi, Yong; Li, Shu; Wang, Dongdong; Wang, Dongzhou; Qi, Yan; Fang, Tao

    2014-11-01

    High power green laser has many applications such as high brightness laser projection and large screen laser theater. A compact and high power green-light source has been developed in diode-pumped solid-state laser based on MgO doped periodically poled LiNbO3 (MgO:PPLN). 5W fiber coupled green laser is achieved by dual path Nd:YVO4/MgO:PPLN intra-cacity frequency-doubled. Single green laser maximum power 2.8W at 532nm is obtained by a 5.5W LD pumped, MgO:PPLN dimensions is 5mm(width)×1mm(thickness)×2mm(length), and the optical to optical conversion efficiency is 51%. The second LD series connected with the one LD, the second path green laser is obtained using the same method. Then the second path light overlap with the first path by the reflection mirrors, then couple into the fiber with a focus mirror. Dual of LD, Nd:YVO4, MgO:PPLN are placed on the same heat sink using a TEC cooling, the operating temperature bandwidth is about 12°C and the stablity is 5% in 96h. A 50×50×17mm3 laser module which generated continuous-wave 5 W green light with high efficiency and width temperature range is demonstrated.

  10. Designing of Raman laser

    International Nuclear Information System (INIS)

    Zidan, M. D.; Al-Awad, F.; Alsous, M. B.

    2005-01-01

    In this work, we describe the design of the Raman laser pumped by Frequency doubled Nd-YAG laser (λ=532 nm) to generate new laser wavelengths by shifting the frequency of the Nd-YAG laser to Stokes region (λ 1 =683 nm, λ 2 =953.6 nm, λ 3 =1579.5 nm) and Antistokes region (λ ' 1 =435 nm, λ ' 2 =369.9 nm, λ ' 3=319.8 nm). Laser resonator has been designed to increase the laser gain. It consists of two mirrors, the back mirror transmits the pump laser beam (λ=532 nm) through the Raman tube and reflects all other generated Raman laser lines. Four special front mirrors were made to be used for the four laser lines λ 1 =683 nm, λ 2 =953.6 nm and λ ' 1 = 435 nm, λ ' 2 =369.9 nm. The output energy for the lines υ 1 s, υ 2 s, υ 1 as,υ 2 as was measured. The output energy of the Raman laser was characterized for different H 2 pressure inside the tube. (Author)

  11. Development of Cr,Nd:GSGG laser as a pumping source of Ti:sapphire laser

    International Nuclear Information System (INIS)

    Tamura, Koji; Arisawa, Takashi

    1999-08-01

    Since efficiency of Cr,Nd doped gadolinium scandium gallium garnet (GSGG) laser is in principle higher than that of Nd:YAG laser, it can be a highly efficient pumping source for Ti:sapphire laser. We have made GSGG laser, and measured its oscillation properties. It was two times more efficient than Nd:YAG laser at free running mode operation. At Q-switched mode operation, fundamental output of 50 mJ and second harmonics output of 8 mJ were obtained. The developed laser had appropriate spatial profile, temporal duration, long time stability for solid laser pumping. Ti:sapphire laser oscillation was achieved by the second harmonics of GSGG laser. (author)

  12. Soft x-ray lasers

    International Nuclear Information System (INIS)

    Matthews, D.L.; Rosen, M.D.

    1988-01-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs

  13. History and principle of lasers

    International Nuclear Information System (INIS)

    Townes, Ch.H.; Schwob, C.; Julien, J.; Forget, S.; Robert-Philip, I.; Balcou, Ph.

    2010-01-01

    In the first article C.H. Townes, the inventor of the maser, describes the work and ideas that led to the invention of the laser. The second article explains how a laser operate and the third article reviews the main different types of laser: solid lasers, gas lasers, diode lasers and dye lasers

  14. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    International Nuclear Information System (INIS)

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD min ) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ

  15. On-Chip Laser-Power Delivery System for Dielectric Laser Accelerators

    Science.gov (United States)

    Hughes, Tyler W.; Tan, Si; Zhao, Zhexin; Sapra, Neil V.; Leedle, Kenneth J.; Deng, Huiyang; Miao, Yu; Black, Dylan S.; Solgaard, Olav; Harris, James S.; Vuckovic, Jelena; Byer, Robert L.; Fan, Shanhui; England, R. Joel; Lee, Yun Jo; Qi, Minghao

    2018-05-01

    We propose an on-chip optical-power delivery system for dielectric laser accelerators based on a fractal "tree-network" dielectric waveguide geometry. This system replaces experimentally demanding free-space manipulations of the driving laser beam with chip-integrated techniques based on precise nanofabrication, enabling access to orders-of-magnitude increases in the interaction length and total energy gain for these miniature accelerators. Based on computational modeling, in the relativistic regime, our laser delivery system is estimated to provide 21 keV of energy gain over an acceleration length of 192 μ m with a single laser input, corresponding to a 108-MV/m acceleration gradient. The system may achieve 1 MeV of energy gain over a distance of less than 1 cm by sequentially illuminating 49 identical structures. These findings are verified by detailed numerical simulation and modeling of the subcomponents, and we provide a discussion of the main constraints, challenges, and relevant parameters with regard to on-chip laser coupling for dielectric laser accelerators.

  16. Laser therapy for cancer

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000905.htm Laser therapy for cancer To use the sharing features ... Lasers are also used on the skin. How Laser Therapy is Used Laser therapy can be used ...

  17. Lasers in Cancer Treatment

    Science.gov (United States)

    ... the advantages of laser therapy? What are the disadvantages of laser therapy? What does the future hold ... therapy is appropriate for them. What are the disadvantages of laser therapy? Laser therapy also has several ...

  18. Laser therapy (image)

    Science.gov (United States)

    A laser is used for many medical purposes. Because the laser beam is so small and precise, it enables ... without injuring surrounding tissue. Some uses of the laser are retinal surgery, excision of lesions, and cauterization ...

  19. Tunable laser optics

    CERN Document Server

    Duarte, FJ

    2015-01-01

    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

  20. Laser cutting system

    Science.gov (United States)

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  1. Laser cooling of solids

    CERN Document Server

    Petrushkin, S V

    2009-01-01

    Laser cooling is an important emerging technology in such areas as the cooling of semiconductors. The book examines and suggests solutions for a range of problems in the development of miniature solid-state laser refrigerators, self-cooling solid-state lasers and optical echo-processors. It begins by looking at the basic theory of laser cooling before considering such topics as self-cooling of active elements of solid-state lasers, laser cooling of solid-state information media of optical echo-processors, and problems of cooling solid-state quantum processors. Laser Cooling of Solids is an important contribution to the development of compact laser-powered cryogenic refrigerators, both for the academic community and those in the microelectronics and other industries. Provides a timely review of this promising field of research and discusses the fundamentals and theory of laser cooling Particular attention is given to the physics of cooling processes and the mathematical description of these processes Reviews p...

  2. Laser physics and a review of laser applications in dentistry for children.

    Science.gov (United States)

    Martens, L C

    2011-04-01

    The aim of this introduction to this special laser issue is to describe some basic laser physics and to delineate the potential of laser-assisted dentistry in children. A brief review of the available laser literature was performed within the scope of paediatric dentistry. Attention was paid to soft tissue surgery, caries prevention and diagnosis, cavity preparation, comfort of the patient, effect on bacteria, long term pulpal vitality, endodontics in primary teeth, dental traumatology and low level laser therapy. Although there is a lack of sufficient evidence taking into account the highest standards for evidence-based dentistry, it is clear that laser application in a number of different aetiologies for soft tissue surgery in children has proven to be successful. Lasers provide a refined diagnosis of caries combined with the appropriate preventive adhesive dentistry after cavity preparation. This will further lead to a new wave of micro-dentistry based on 'filling without drilling'. It has become clear from a review of the literature that specific laser applications in paediatric dentistry have gained increasing importance. It can be concluded that children should be considered as amongst the first patients for receiving laser-assisted dentistry.

  3. Femtosecond laser inscribed cladding waveguide lasers in Nd:LiYF4 crystals

    Science.gov (United States)

    Li, Shi-Ling; Huang, Ze-Ping; Ye, Yong-Kai; Wang, Hai-Long

    2018-06-01

    Depressed circular cladding, buried waveguides were fabricated in Nd:LiYF4 crystals with an ultrafast Yb-doped fiber master-oscillator power amplifier laser. Waveguides were optimized by varying the laser writing conditions, such as pulse energy, focus depth, femtosecond laser polarization and scanning velocity. Under optical pump at 799 nm, cladding waveguides showed continuous-wave laser oscillation at 1047 nm. Single- and multi-transverse modes waveguide laser were realized by varying the waveguide diameter. The maximum output power in the 40 μm waveguide is ∼195 mW with a slope efficiency of 34.3%. The waveguide lasers with hexagonal and cubic cladding geometry were also realized.

  4. Advanced Laser Architecture for Two-Step Laser Tandem Mass Spectrometer

    Science.gov (United States)

    Fahey, Molly E.; Li, Steven X.; Yu, Anthony W.; Getty, Stephanie A.

    2016-01-01

    Future astrobiology missions will focus on planets with significant astrochemical or potential astrobiological features, such as small, primitive bodies and the icy moons of the outer planets that may host diverse organic compounds. These missions require advanced instrument techniques to fully and unambiguously characterize the composition of surface and dust materials. Laser desorptionionization mass spectrometry (LDMS) is an emerging instrument technology for in situ mass analysis of non-volatile sample composition. A recent Goddard LDMS advancement is the two-step laser tandem mass spectrometer (L2MS) instrument to address the need for future flight instrumentation to deconvolve complex organic signatures. The L2MS prototype uses a resonance enhanced multi-photon laser ionization mechanism to selectively detect aromatic species from a more complex sample. By neglecting the aliphatic and inorganic mineral signatures in the two-step mass spectrum, the L2MS approach can provide both mass assignments and clues to structural information for an in situ investigation of non-volatile sample composition. In this paper we will describe our development effort on a new laser architecture that is based on the previously flown Lunar Orbiter Laser Altimeter (LOLA) laser transmitter for the L2MS instrument. The laser provides two discrete midinfrared wavelengths (2.8 m and 3.4 m) using monolithic optical parametric oscillators and ultraviolet (UV) wavelength (266 nm) on a single laser bench with a straightforward development path toward flight readiness.

  5. Laser in operative dentistry

    Directory of Open Access Journals (Sweden)

    E. Yasini

    1994-06-01

    Full Text Available Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry, etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks around the region of laser radiation. Also due to high temperature of these lasers, pulp damage is inevitable. So today, by using the Excimer laser especially the argon floride type with a wavelength of 193 nm, the problem of heat stress have been solved, but the use of lasers in dentistry, especially for cavity preparation needs more researches and evaluations.

  6. Flexible Laser Metal Cutting

    DEFF Research Database (Denmark)

    Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten

    2014-01-01

    This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

  7. Measurement of the emission spectrum of a semiconductor laser using laser-feedback interferometry.

    Science.gov (United States)

    Keeley, James; Freeman, Joshua; Bertling, Karl; Lim, Yah L; Mohandas, Reshma A; Taimre, Thomas; Li, Lianhe H; Indjin, Dragan; Rakić, Aleksandar D; Linfield, Edmund H; Davies, A Giles; Dean, Paul

    2017-08-03

    The effects of optical feedback (OF) in lasers have been observed since the early days of laser development. While OF can result in undesirable and unpredictable operation in laser systems, it can also cause measurable perturbations to the operating parameters, which can be harnessed for metrological purposes. In this work we exploit this 'self-mixing' effect to infer the emission spectrum of a semiconductor laser using a laser-feedback interferometer, in which the terminal voltage of the laser is used to coherently sample the reinjected field. We demonstrate this approach using a terahertz frequency quantum cascade laser operating in both single- and multiple-longitudinal mode regimes, and are able to resolve spectral features not reliably resolved using traditional Fourier transform spectroscopy. We also investigate quantitatively the frequency perturbation of individual laser modes under OF, and find excellent agreement with predictions of the excess phase equation central to the theory of lasers under OF.

  8. Lasers in chemical processing

    International Nuclear Information System (INIS)

    Davis, J.I.

    1982-01-01

    The high cost of laser energy is the crucial issue in any potential laser-processing application. It is expensive relative to other forms of energy and to most bulk chemicals. We show those factors that have previously frustrated attempts to find commercially viable laser-induced processes for the production of materials. Having identified the general criteria to be satisfied by an economically successful laser process and shown how these imply the laser-system requirements, we present a status report on the uranium laser isotope separation (LIS) program at the Lawrence Livermore National Laboratory

  9. Laser power supply

    International Nuclear Information System (INIS)

    Bernstein, D.

    1975-01-01

    The laser power supply includes a regulator which has a high voltage control loop based on a linear approximation of a laser tube negative resistance characteristic. The regulator has independent control loops for laser current and power supply high voltage

  10. Lasers in endodontics: an overview

    Science.gov (United States)

    Frentzen, Matthias; Braun, Andreas; Koort, Hans J.

    2002-06-01

    The interest in endodontic use of dental laser systems is increasing. Developing laser technology and a better understanding of laser effects widened the spectrum of possible endodontic indications. Various laser systems including excimer-, argon+-, diode-, Nd:YAG-, Er:YAG- and CO2-lasers are used in pulp diagnosis, treatment of hypersensitivity, pulp capping, sterilization of root canals, root canal shaping and obturation or apicoectomy. With the development of new delivery systems - thin and flexible fibers - for many different wavelengths laser applications in endodontics may increase. Since laser devices are still relatively costly, access to them is limited. Most of the clinical applications are laser assisted procedures such as the removing of pulp remnants and debris or disinfection of infected root canals. The essential question is whether a laser can provide improved treatment over conventional care. To perform laser therapy in endodontics today different laser types with adopted wavelengths and pulse widths are needed, each specific to a particular application. Looking into the future we will need endodontic laser equipment providing optimal laser parameters for different treatment modalities. Nevertheless, the quantity of research reports from the last decade promises a genuine future for lasers in endodontics.

  11. Cutting using the CO laser. Trennen mit dem CO-Laser

    Energy Technology Data Exchange (ETDEWEB)

    Maisenhaelder, F.; Stoehr, M. (DLR, Inst. fuer Technische Physik, Stuttgart (Germany))

    1991-02-01

    Several cutting experiments were performed to investigate the maximum cutting speed when using CO or CO{sub 2} laser radiation. The material which was used for these experiments was mild steel (St 37) and stainless steel (V2A; X5CrNi 189), the material thickness varied from 0.5 mm to 4 mm. The cutting parameters, especially the focal power density and the focal diameter, were equal for both laser wavelengths. The experimental result shows an increased cutting speed with CO laser beams in comparison to CO{sub 2} laser beams.

  12. Laser marking method and device

    International Nuclear Information System (INIS)

    Okazaki, Yuki; Aoki, Nobutada; Mukai, Narihiko; Sano, Yuji; Yamamoto, Seiji.

    1997-01-01

    An object is disposed in laser beam permeating liquid or gaseous medium. Laser beams such as CW laser or pulse laser oscillated from a laser device are emitted to the object to apply laser markings with less degradation of identification and excellent corrosion resistance on the surface of the object simply and easily. Upon applying the laser markings, a liquid or gas as a laser beam permeating medium is blown onto the surface of the object, or the liquid or gas in the vicinity of the object is sucked, the laser beam-irradiated portion on the surface can be cooled positively. Accordingly, the laser marking can be formed on the surface of the object with less heat affection to the object. In addition, if the content of a nitrogen gas in the laser beam permeating liquid medium is reduced by degassing to lower than a predetermined value, or the laser beam permeating gaseous medium is formed by an inert gas, a laser marking having high corrosion resistance and reliability can be formed on the surface of the objective member. (N.H.)

  13. CO laser angioplasty system: efficacy of manipulatable laser angioscope catheter

    Science.gov (United States)

    Arai, Tsunenori; Kikuchi, Makoto; Mizuno, Kyoichi; Sakurada, Masami; Miyamoto, Akira; Arakawa, Koh; Kurita, Akira; Nakamura, Haruo; Takeuchi, Kiyoshi; Utsumi, Atsushi; Akai, Yoshiro

    1992-08-01

    A percutaneous transluminal coronary angioplasty system using a unique combination of CO laser (5 micrometers ) and As-S infrared glass fiber under the guidance of a manipulatable laser angioscope catheter is described. The ablation and guidance functions of this system are evaluated. The angioplasty treatment procedure under angioscope guidance was studied by in vitro model experiment and in vivo animal experiment. The whole angioplasty system is newly developed. That is, a transportable compact medical CO laser device which can emit up to 10 W, a 5 F manipulatable laser angioscope catheter, a thin CO laser cable of which the diameter is 0.6 mm, an angioscope imaging system for laser ablation guidance, and a system controller were developed. Anesthetized adult mongrel dogs (n equals 5) with an artificial complete occlusion in the femoral artery and an artificial human vessel model including occluded or stenotic coronary artery were used. The manipulatability of the catheter was drastically improved (both rotation and bending), therefore, precise control of ablation to expand stenosis was obtained. A 90% artificial stenosis made of human yellow plaque in 4.0 mm diameter in the vessel was expanded to 70% stenosis by repetitive CO laser ablations of which total energy was 220 J. All procedures were performed and controlled under angioscope visualization.

  14. Laser welding engineering

    International Nuclear Information System (INIS)

    Bhieh, N. M.; El Eesawi, M. E.; Hashkel, A. E.

    2007-01-01

    Laser welding was in its early life used mainly for unusual applications where no other welding process would be suitable that was twenty five years ago. Today, laser welding is a fully developed part of the metal working industry, routinely producing welds for common items such as cigarette lighters, which springs, motor/transformer lamination, hermetic seals, battery and pacemaker cans and hybrid circuit packages. Yet very few manufacturing engineering have seriously considers employing lasers in their own operations. Why? There are many reasons, but a main one must be not acquainted with the operation and capabilities of a laser system. Other reasons, such as a relatively high initial cost and a concern about using lasers in the manufacturing environment, also are frequently cited, and the complexity of the component and flexibility of the light delivery system. Laser welding could be used in place of many different standard processes, such as resistance (spot or seam), submerged arc, RF induction, high-frequency resistance, ultrasonic and electronic and electron-beam. while each of these techniques has established an independent function in the manufacturing world, the flexible laser welding approach will operate efficiently and economically in many different applications. Its flexibility will even permit the welding system to be used for other machining function, such as drilling, scribing, sealing and serializing. In this article, we will look at how laser welding works and what benefits it can offer to manufacturing engineers. Some industry observers state that there are already 2,000 laser machine tools being used for cutting, welding and drilling and that the number could reach 30,000 over the next 15 years as manufacturing engineers become more aware of the capabilities of lasers [1). While most laser applications are dedicated to one product or process that involves high-volume, long-run manufacturing, the flexibility of a laser to supply energy to hard

  15. Teradiode's high brightness semiconductor lasers

    Science.gov (United States)

    Huang, Robin K.; Chann, Bien; Burgess, James; Lochman, Bryan; Zhou, Wang; Cruz, Mike; Cook, Rob; Dugmore, Dan; Shattuck, Jeff; Tayebati, Parviz

    2016-03-01

    TeraDiode is manufacturing multi-kW-class ultra-high brightness fiber-coupled direct diode lasers for industrial applications. A fiber-coupled direct diode laser with a power level of 4,680 W from a 100 μm core diameter, BPP) of 3.5 mm-mrad and is the lowest BPP multi-kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 4-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers. We have also demonstrated novel high peak power lasers and high brightness Mid-Infrared Lasers.

  16. Color speckle in laser displays

    Science.gov (United States)

    Kuroda, Kazuo

    2015-07-01

    At the beginning of this century, lighting technology has been shifted from discharge lamps, fluorescent lamps and electric bulbs to solid-state lighting. Current solid-state lighting is based on the light emitting diodes (LED) technology, but the laser lighting technology is developing rapidly, such as, laser cinema projectors, laser TVs, laser head-up displays, laser head mounted displays, and laser headlamps for motor vehicles. One of the main issues of laser displays is the reduction of speckle noise1). For the monochromatic laser light, speckle is random interference pattern on the image plane (retina for human observer). For laser displays, RGB (red-green-blue) lasers form speckle patterns independently, which results in random distribution of chromaticity, called color speckle2).

  17. Recent laser experiments on the Aurora KrF/ICF laser system

    International Nuclear Information System (INIS)

    Turner, T.P.; Jones, J.E.; Czuchlewski, S.J.; Watt, R.G.; Thomas, S.J.; Kang, M.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    The Aurora KrF/ICF Laser Facility at Los Alamos is operational at the kilojoule-level for both laser and target experiments. We report on recent laser experiments on the system and resulting system improvements. 3 refs., 4 figs

  18. Laser for fusion energy

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1995-01-01

    Solid state lasers have proven to be very versatile tools for the study and demonstration of inertial confinement fusion principles. When lasers were first contemplated to be used for the compression of fusion fuel in the late 1950s, the laser output energy levels were nominally one joule and the power levels were 10 3 watts (pulse duration's of 10 -3 sec). During the last 25 years, lasers optimized for fusion research have been increased in power to typically 100,000 joules with power levels approaching 10 14 watts. As a result of experiments with such lasers at many locations, DT target performance has been shown to be consistent with high gain target output. However, the demonstration of ignition and gain requires laser energies of several megajoules. Laser technology improvements demonstrated over the past decade appear to make possible the construction of such multimegajoule lasers at affordable costs. (author)

  19. Laser Processing and Chemistry

    CERN Document Server

    Bäuerle, Dieter

    2011-01-01

    This book gives an overview of the fundamentals and applications of laser-matter interactions, in particular with regard to laser material processing. Special attention is given to laser-induced physical and chemical processes at gas-solid, liquid-solid, and solid-solid interfaces. Starting with the background physics, the book proceeds to examine applications of lasers in “standard” laser machining and laser chemical processing (LCP), including the patterning, coating, and modification of material surfaces. This fourth edition has been enlarged to cover the rapid advances in the understanding of the dynamics of materials under the action of ultrashort laser pulses, and to include a number of new topics, in particular the increasing importance of lasers in various different fields of surface functionalizations and nanotechnology. In two additional chapters, recent developments in biotechnology, medicine, art conservation and restoration are summarized. Graduate students, physicists, chemists, engineers, a...

  20. Laser applications for energy. Fifty years since advent of laser and next thirty years

    International Nuclear Information System (INIS)

    Nakai, Sadao

    2011-01-01

    The utilization of light has been changed since the advent of lasers about fifty years ago. Now in the twenty first century, laser science is being applied in every industry as the fundamental technology. In the recent years, remarkable progresses have been made in the semiconductor lasers of high power and wide wavelength region. The amazing developments of ceramics laser materials like YAG and nonlinear optics materials of organic crystals have been achieved as well as the big progress in the fiber lasers. It is also to be pointed out that very high power ultra short laser pulses have become available. In the field of power photonics, which is based on the power semiconductor lasers, fiber lasers and new laser materials, various industrial applications are expected to be constructed further in civil engineering, manufacturing technology, agricultural and biological applications, medical utilization and space sciences. It is expected, by the development of ultra short pulse and ultra high mean power lasers, that particle accelerations, ultra high density sciences, nuclear fusion neutron sources and laser fusion power reactors are to be advanced drastically. Recent development and future prospects of high power lasers are illustrated. Lasers are now regarded as one of the key technologies in line with the national policy toward the creation of innovative industries. Realization of the laser fusion reactor is the most challenging target in the coming thirty years. (S. Funahashi)

  1. Disk laser: a new generation of industrial lasers

    Science.gov (United States)

    Brockmann, Rüdiger; Havrilla, David

    2009-02-01

    The disk laser concept aggregates high efficiency, excellent beam quality, high average and peak power with moderate cost and high reliability. Therefore it became one major technology in industrial laser material processing. In several large scale installations in the automotive industry, high power cw- systems make already use of the high brightness and high efficiency of disk lasers, e.g. in remote welding [1,2]. Other applications including cutting, drilling, deep welding and hybrid welding are arising. This report highlights the latest results in cw disk laser development. A 1.5 kW source with a beam parameter product (BPP) of 2 mm mrad is described as well as the demonstration of a 14 kW system out of three disks with a BPP of 8 mm mrad. The future prospects regarding increased power and even further improved productivity and economics are presented. A new industrial disk laser series with output powers up to 16 kW and a beam parameter product of 8 mm*mrad will enable both, new applications in the thick sheet area and very cost efficient high productive applications like welding and cutting of thin sheets.

  2. Laser development for laser fusion applications. Research progress report, October 1979-September 1980

    International Nuclear Information System (INIS)

    1981-04-01

    Research conducted during this period is reported on the following: (1) rare-gas-halogen lasers, (2) XeCl laser at excitation rates of 1.7 to 4.7 MW/cm 3 , (3) rare gas halogen laser modeling, (4) three-body ion recombination coefficients, (5) electron beam accelerators, (6) power conditioning studies for accelerators, (7) chemically pumped iodine lasers, (8) hydrogen fluoride lasers, and (9) supporting research

  3. A low-cost, tunable laser lock without laser frequency modulation

    Science.gov (United States)

    Shea, Margaret E.; Baker, Paul M.; Gauthier, Daniel J.

    2015-05-01

    Many experiments in optical physics require laser frequency stabilization. This can be achieved by locking to an atomic reference using saturated absorption spectroscopy. Often, the laser frequency is modulated and phase sensitive detection used. This method, while well-proven and robust, relies on expensive components, can introduce an undesirable frequency modulation into the laser, and is not easily frequency tuned. Here, we report a simple locking scheme similar to those implemented previously. We modulate the atomic resonances in a saturated absorption setup with an AC magnetic field created by a single solenoid. The same coil applies a DC field that allows tuning of the lock point. We use an auto-balanced detector to make our scheme more robust against laser power fluctuations and stray magnetic fields. The coil, its driver, and the detector are home-built with simple, cheap components. Our technique is low-cost, simple to setup, tunable, introduces no laser frequency modulation, and only requires one laser. We gratefully acknowledge the financial support of the NSF through Grant # PHY-1206040.

  4. CO2 laser pulse shortening by laser ablation of a metal target

    International Nuclear Information System (INIS)

    Donnelly, T.; Mazoyer, M.; Lynch, A.; O'Sullivan, G.; O'Reilly, F.; Dunne, P.; Cummins, T.

    2012-01-01

    A repeatable and flexible technique for pulse shortening of laser pulses has been applied to transversely excited atmospheric (TEA) CO 2 laser pulses. The technique involves focusing the laser output onto a highly reflective metal target so that plasma is formed, which then operates as a shutter due to strong laser absorption and scattering. Precise control of the focused laser intensity allows for timing of the shutter so that different temporal portions of the pulse can be reflected from the target surface before plasma formation occurs. This type of shutter enables one to reduce the pulse duration down to ∼2 ns and to remove the low power, long duration tails that are present in TEA CO 2 pulses. The transmitted energy is reduced as the pulse duration is decreased but the reflected power is ∼10 MW for all pulse durations. A simple laser heating model verifies that the pulse shortening depends directly on the plasma formation time, which in turn is dependent on the applied laser intensity. It is envisaged that this plasma shutter will be used as a tool for pulse shaping in the search for laser pulse conditions to optimize conversion efficiency from laser energy to useable extreme ultraviolet (EUV) radiation for EUV source development.

  5. Laser safety tools and training

    CERN Document Server

    Barat, Ken

    2008-01-01

    Lasers perform many unique functions in a plethora of applications, but there are many inherent risks with this continually burgeoning technology. Laser Safety: Tools and Training presents simple, effective ways for users in a variety of facilities to evaluate the hazards of any laser procedure and ensure they are following documented laser safety standards.Designed for use as either a stand-alone volume or a supplement to Laser Safety Management, this text includes fundamental laser and laser safety information and critical laser use information rarely found in a single source. The first lase

  6. Injection-controlled laser resonator

    Science.gov (United States)

    Chang, J.J.

    1995-07-18

    A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

  7. High power laser research and development at the Laboratory for Laser Energetics

    International Nuclear Information System (INIS)

    Soures, J.M.; McCrory, R.L.; Cerqua, K.A.

    1986-01-01

    As part of its research mission - to investigate the interaction of intense radiation with matter - the Laboratory for Laser Energetics (LLE) of the University of Rochester is developing a number of high-peak power and high-average-power laser systems. In this paper we highlight some of the LLE work on solid-state laser research, development and applications. Specifically, we discuss the performance and operating characteristics of Omega, a twenty-four beam, 4000 Joule, Nd:glass laser system which is frequently tripled using the polarization mismatch scheme. We also discuss progress in efforts to develop high-average-power solid-state laser systems with active-mirror and slab geometries and to implement liquid-crystal devices in high-power Nd:glass lasers. Finally we present results from a program to develop a compact, ultrahigh-peak-power solid-state laser using the concept of frequency chirped pulse amplification

  8. Verification of a characterization method of the laser-induced selective activation based on industrial lasers

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard; Tang, Peter T.

    2013-01-01

    In this article, laser-induced selective activation (LISA) for subsequent autocatalytic copper plating is performed by several types of industrial scale lasers, including a Nd:YAG laser, a UV laser, a fiber laser, a green laser, and a short pulsed laser. Based on analysis of all the laser......-machined surfaces, normalized bearing area curves and parameters are used to characterize the surface quantitatively. The range of normalized bearing area curve parameters for plate-able surface is suggested. PBT/PET with 40 % glass fiber was used as the substrate material. For all of the studied lasers......, the parameters were varied in a relatively large range, and matrixes of the laser-machined surface were obtained. The topography of those laser-machined surfaces was examined by scanning electronic microscope (SEM). For each sample examined by SEM, there was an identical workpiece plated by for 90 min...

  9. Dependence of Parameters of Laser-Produced Au Plasmas on the Incident Laser Energy of Sub-Nanosecond and Picosecond Laser Pulses

    International Nuclear Information System (INIS)

    Woryna, E.; Badziak, J.; Makowski, J.; Parys, P.; Vankov, A.B.; Wolowski, J.; Krasa, J.; Laska, L.; Rohlena, K.

    2001-01-01

    The parameters of Au plasma as functions of laser energy for ps pulses are presented and compared with the ones for sub-ns pulses at nearly the same densities of laser energy. The experiments were performed at the IPPLM with the use of CPA (chirped pulse amplification) Nd:glass laser system. Thick Au foil targets were irradiated by normally incident focused laser beams with maximum intensities of 8x10 16 and 2x10 14 W/cm 2 for ps and sub-ns laser pulses, respectively. The characteristics of ion streams were investigated with the use of ion diagnostics methods based on the time-of flight technique. In these experiments the laser energies were changed in the range from 90 to 700 mJ and the measurements were performed at a given focus position FP = 0 and along the target normal for both the laser pulses. The charge carried by the ions, the maximum ion velocities of fast and thermal ion groups, the maximum ion current density as well as the area of photopeak in dependence on the incident laser energy for sub-ns and ps pulses were investigated and discussed. (author)

  10. Active-passively mode-locked dye laser for diagnosis of laser-produced plasmas

    International Nuclear Information System (INIS)

    Teng, Y.L.; Fedosejevs, R.; Sigel, R.

    1981-03-01

    In this report an active-passively mode-locked, flashlamp-pumped dye laser for diagnosis of laser-produced plasmas is described. This dye laser system used as a pulsed light source for high-speed photography of laser-target experiments was synchronized to the ASTERIX III iodine laser pulse with better than 100 ps accuracy. The single pulse energy was 10 μJ, pulse duration less than 10 ps. In 111 shots clear shadowgrams were obtained during a total of 151 target shots, i.e. the system worked well in 74% of the shots. (orig.)

  11. Solar pumped laser

    Science.gov (United States)

    Lee, J. H.; Hohl, F.; Weaver, W. R. (Inventor)

    1984-01-01

    A solar pumped laser is described in which the lasant is a gas that will photodissociate and lase when subjected to sunrays. Sunrays are collected and directed onto the gas lasant to cause it to lase. Applications to laser propulsion and laser power transmission are discussed.

  12. Diode lasers optimized in brightness for fiber laser pumping

    Science.gov (United States)

    Kelemen, M.; Gilly, J.; Friedmann, P.; Hilzensauer, S.; Ogrodowski, L.; Kissel, H.; Biesenbach, J.

    2018-02-01

    In diode laser applications for fiber laser pumping and fiber-coupled direct diode laser systems high brightness becomes essential in the last years. Fiber coupled modules benefit from continuous improvements of high-power diode lasers on chip level regarding output power, efficiency and beam characteristics resulting in record highbrightness values and increased pump power. To gain high brightness not only output power must be increased, but also near field widths and far field angles have to be below a certain value for higher power levels because brightness is proportional to output power divided by beam quality. While fast axis far fields typically show a current independent behaviour, for broadarea lasers far-fields in the slow axis suffer from a strong current and temperature dependence, limiting the brightness and therefore their use in fibre coupled modules. These limitations can be overcome by carefully optimizing chip temperature, thermal lensing and lateral mode structure by epitaxial and lateral resonator designs and processing. We present our latest results for InGaAs/AlGaAs broad-area single emitters with resonator lengths of 4mm emitting at 976nm and illustrate the improvements in beam quality over the last years. By optimizing the diode laser design a record value of the brightness for broad-area lasers with 4mm resonator length of 126 MW/cm2sr has been demonstrated with a maximum wall-plug efficiency of more than 70%. From these design also pump modules based on 9 mini-bars consisting of 5 emitters each have been realized with 360W pump power.

  13. Longitudinally excited CO2 laser with multiple laser tubes

    Science.gov (United States)

    Uno, Kazuyuki; Akitsu, Tetsuya; Jitsuno, Takahisa

    2016-11-01

    We developed a longitudinally excited CO2 laser system that was constituted of two or three laser tubes and a single driving circuit. The multiple laser tubes simultaneously produced almost the same short laser pulses with a spike pulse width of about 164 ns and a pulse tail length of about 74 μs with a single driving circuit. The double-tube system was constituted of two 30 cm-long laser tubes with inner diameters of 13 mm and 16 mm and a single driving circuit with an input energy of 2.18 J. The output energy of the 13 mm-tube was 23.3 mJ, and that of the 16 mm-tube was 21.9 mJ at a gas pressure of 4.2 kPa (CO2:N2:He = 1:1:2). The triple-tube system was constituted of three 30 cm-long laser tubes with inner diameters of 9 mm, 13 mm, and 16 mm and a single driving circuit with an input energy of 2.18 J. The output energy of the 9 mm tube was 15.9 mJ, that of the 13 mm tube was 24.1 mJ, and that of the 16 mm tube was 19.2 mJ at a gas pressure of 4.2 kPa. With the same driving circuit and the same input energy, the total output energies of the multitube laser systems were higher than the output energy of a single-tube system.

  14. Technology of discharge and laser resonators for high power CO2 lasers. Koshutsuryoku CO2 laser ni tsukawareru hoden reiki laser kyoshinki gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Takenaka, Y.; Kuzumoto, M. (Mitsubishi Electric Corp., Tokyo (Japan))

    1994-03-20

    This paper describes discharge excitation technology and resonator technology as basic technologies for high power CO2 lasers. As a result of progress in high-frequency power element techniques, the discharge excitation technology now generally uses laser excitation using AC discharge of capacity coupling type. Its representative example is silent discharge (SD) excitation. This is a system to excite laser by applying high voltages with as high frequency as 100 kHz to 1 MHz across a pair of electrodes covered with a dielectric material. The system maintains stability in discharge even if power supply voltage amplitude is modulated, and easily provides pulse outputs. Discharge excitation for diffusion cooled type CO2 laser generates a discharge in a gap with a gap length of about 2 mm, and can perform gas cooling by means of thermal conduction of gas, whereas a compact resonator can be fabricated. A resonator for the diffusion cooled type CO2 laser eliminates gas circulation and cooling systems, hence the device can be made more compact. A report has been given that several of these compact resonators were combined, from which a laser output of 85W was obtained by using RF discharge of 2kW. 43 refs., 21 figs.

  15. Nuclear-pumped lasers

    CERN Document Server

    Prelas, Mark

    2016-01-01

    This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....

  16. Atomic iodine laser

    International Nuclear Information System (INIS)

    Fisk, G.A.; Gusinow, M.A.; Hays, A.K.; Padrick, T.D.; Palmer, R.E.; Rice, J.K.; Truby, F.K.; Riley, M.E.

    1978-05-01

    The atomic iodine photodissociation laser has been under intensive study for a number of years. The physics associated with this system is now well understood and it is possible to produce a 0.1 nsec (or longer) near-diffraction-limited laser pulse which can be amplified with negligible temporal distortion and little spatial deformation. The output of either a saturated or unsaturated amplifier consists of a high-fidelity near-diffraction-limited, energetic laser pulse. The report is divided into three chapters. Chapter 1 is a survey of the important areas affecting efficient laser operation and summarizes the findings of Chap. 2. Chapter 2 presents detailed discussions and evaluations pertinent to pumps, chemical regeneration, and other elements in the overall laser system. Chapter 3 briefly discusses those areas that require further work and the nature of the work required to complete the full-scale evaluation of the applicability of the iodine photodissociation laser to the inertial confinement program

  17. Principles of Lasers

    CERN Document Server

    Svelto, Orazio

    2010-01-01

    This new Fifth Edition of Principles of Lasers incorporates corrections to the previous edition. The text’s essential mission remains the same: to provide a wide-ranging yet unified description of laser behavior, physics, technology, and current applications. Dr. Svelto emphasizes the physical rather than the mathematical aspects of lasers, and presents the subject in the simplest terms compatible with a correct physical understanding. Praise for earlier editions: "Professor Svelto is himself a longtime laser pioneer and his text shows the breadth of his broad acquaintance with all aspects of the field … Anyone mastering the contents of this book will be well prepared to understand advanced treatises and research papers in laser science and technology." (Arthur L. Schawlow, 1981 Nobel Laureate in Physics) "Already well established as a self-contained introduction to the physics and technology of lasers … Professor Svelto’s book, in this lucid translation by David Hanna, can be strongly recommended for...

  18. Improvements of the ruby laser oscillator system for laser scattering

    International Nuclear Information System (INIS)

    Yamauchi, Toshihiko; Kumagai, Katsuaki; Kawakami, Tomohide; Matoba, Tohru; Funahashi, Akimasa

    1978-10-01

    A ruby laser oscillator system is used to measure electron temperatures of the Tokamak plasmas(JFT-2 and JFT-2a). Improvements have been made of the laser oscillator to obtain the correct values. Described are the improvements and the damages of a ruby rod and a KD*P crystal for Q-switching by laser beam. Improvement are the linear Xe lamp replaced by a helical Xe lamp and in the electrical circuit for Q-switching. The damage of an optical component by a laser beam should be clarified from the damage data; the cause is not found yet. (author)

  19. Direct pumping of ultrashort Ti:sapphire lasers by a frequency doubled diode laser

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Unterhuber, Angelika

    2011-01-01

    electro-optical efficiency of the diode laser. Autocorrelation measurements show that pulse widths of less than 20 fs can be expected with an average power of 52 mW when using our laser. These results indicate the high potential of direct diode laser pumped Ti: sapphire lasers to be used in applications....... When using our diode laser system, the optical conversion efficiencies from green to near-infrared light reduces to 75 % of the values achieved with the commercial pump laser. Despite this reduction the overall efficiency of the Ti: sapphire laser is still increased by a factor > 2 due to the superior...... like retinal optical coherence tomography (OCT) or pumping of photonic crystal fibers for CARS (coherent anti-stokes Raman spectroscopy) microscopy....

  20. Laser-induced stresses versus mechanical stress power measurements during laser ablation of solids

    International Nuclear Information System (INIS)

    Shannon, M.A.; Russo, R.E.

    1995-01-01

    Laser-induced stresses resulting from high-power laser-material interactions have been studied extensively. However, the rate of change in mechanical energy, or stress power, due to laser-induced stresses has only recently been investigated. An unanswered question for monitoring laser-material interactions in the far-field is whether stress power differs from stresses measured, particularly with respect to laser-energy coupling to a solid target. This letter shows experimental acoustic data which demonstrate that stress power measured in the far field of the target shows changes in laser-energy coupling, whereas the stresses measured do not. For the ambient medium above the target, stress power and stress together reflect changes in laser-energy coupling. copyright 1995 American Institute of Physics

  1. Determinants of holmium:yttrium-aluminum-garnet laser time and energy during ureteroscopic laser lithotripsy.

    Science.gov (United States)

    Molina, Wilson R; Marchini, Giovanni S; Pompeo, Alexandre; Sehrt, David; Kim, Fernando J; Monga, Manoj

    2014-04-01

    To evaluate the association of preoperative noncontrast computed tomography stone characteristics, laser settings, and stone composition with cumulative holmium:yttrium-aluminum-garnet (Ho:YAG) laser time/energy. We retrospectively reviewed patients who underwent semirigid/flexible ureteroscopy and Ho:YAG laser lithotripsy (200 or 365 μm laser fiber; 0.8-1.0 J energy; and 8-10 Hz rate) at 2 tertiary care centers (April 2010-May 2012). Studied parameters were as follows: patient's characteristics; stone characteristics (location, burden, hardness, and composition); total laser time and energy; and surgical outcomes. One hundred patients met our inclusion criteria. Mean stone size was 1.01 ± 0.42 cm and volume 0.33 ± 0.04 cm(3). Mean stone radiodensity was 990 ± 296 HU, and Hounsfield units density 13.8 ± 6.0 HU/mm. All patients were considered stone free. Stone size and volume had a significant positive correlation with laser energy (R = 0.516, P R = 0.621, P R = 0.477, P R = 0.567, P stone size, only the correlation between HU and laser time was significant (R = 0.262, P = .011). In the multivariate analysis, with exception of stone composition (P = .103), all parameters significantly increased laser energy (R(2) = 0.524). Multivariate analysis revealed a positive significant association of laser time with stone volume (P R(2) = 0.512). In multivariate analysis for laser energy, only calcium phosphate stones required less energy to fragment compared with uric acid stones. No significant differences were found in the multivariate laser time model. Ho:YAG laser cumulative energy and total time are significantly affected by stone dimensions, hardness location, fiber size, and power. Kidney location, laser fiber size, and laser power have more influence on the final laser energy than on the total laser time. Calcium phosphate stones require less laser energy to fragment. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Lasers: principles, applications and energetic measures

    International Nuclear Information System (INIS)

    Subran, C.; Sagaut, J.; Lapointe, S.

    2009-01-01

    After having recalled the principles of a laser and the properties of the laser beam, the authors describe the following different types of lasers: solid state lasers, fiber lasers, semiconductor lasers, dye lasers and gas lasers. Then, their applications are given. Very high energy lasers can reproduce the phenomenon of nuclear fusion of hydrogen atoms. (O.M.)

  3. Laser performance upgrade for precise ICF experiment in SG-Ⅲ laser facility

    Directory of Open Access Journals (Sweden)

    Wanguo Zheng

    2017-09-01

    Full Text Available The SG-Ⅲ laser facility (SG-Ⅲ is the largest laser driver for inertial confinement fusion (ICF researches in China, which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns. In order to meet the requirements of precise physics experiments, some new functionalities need to be added to SG-Ⅲ and some intrinsic laser performances need upgrade. So at the end of SG-Ⅲ's engineering construction, the 2-year laser performance upgrade project started. This paper will introduce the newly added functionalities and the latest laser performance of SG-Ⅲ. With these function extensions and performance upgrade, SG-Ⅲ is now fully prepared for precise ICF experiments and solidly paves the way towards fusion ignition.

  4. Stabilizing laser energy density on a target during pulsed laser deposition of thin films

    Science.gov (United States)

    Dowden, Paul C.; Jia, Quanxi

    2016-05-31

    A process for stabilizing laser energy density on a target surface during pulsed laser deposition of thin films controls the focused laser spot on the target. The process involves imaging an image-aperture positioned in the beamline. This eliminates changes in the beam dimensions of the laser. A continuously variable attenuator located in between the output of the laser and the imaged image-aperture adjusts the energy to a desired level by running the laser in a "constant voltage" mode. The process provides reproducibility and controllability for deposition of electronic thin films by pulsed laser deposition.

  5. Laser transmitter system

    International Nuclear Information System (INIS)

    Dye, R.A.

    1975-01-01

    A laser transmitter system is disclosed which utilizes mechanical energy for generating an output pulse. The laser system includes a current developing device such as a piezoelectric crystal which charges a storage device such as a capacitor in response to a mechanical input signal. The capacitor is coupled to a switching device, such as a silicon controlled rectifier (SCR). The switching device is coupled to a laser transmitter such as a GaAs laser diode, which provides an output signal in response to the capacitor being discharged

  6. Regenerative similariton laser

    Directory of Open Access Journals (Sweden)

    Thibault North

    2016-05-01

    Full Text Available Self-pulsating lasers based on cascaded reshaping and reamplification (2R are capable of initiating ultrashort pulses despite the accumulation of large amounts of nonlinearities in all-fiber resonators. The spectral properties of pulses in self-similar propagation are compatible with cascaded 2R regeneration by offset filtering, making parabolic pulses suitable for the design of a laser of this recently introduced class. A new type of regenerative laser giving birth to similaritons is numerically investigated and shows that this laser is the analog of regenerative sources based solely on self-phase modulation and offset filtering. The regenerative similariton laser does not suffer from instabilities due to excessive nonlinearities and enables ultrashort pulse generation in a simple cavity configuration.

  7. 1.8kW laser diode pumped YAG laser; Shutsuryoku 1.8kW no handotai laser reiki YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Toshiba Corporation, as a participant in Ministry of International Trade and Industry`s `photon measurement and processing technology project` since August, 1997, is engaged in the development of an energy-efficient LD (laser diode) pumped semiconductor YAG (yttrium-aluminum-garnet) laser device to be used for welding and cutting. It is a 5-year project and the goal is a mean output of 10kW and efficiency of 20%. In this article, a simulation program is developed which carries out calculation about element technology items such as the tracking of the beam from the pumping LD and the excitation distribution, temperature distribution, thermal stress distribution, etc., in the YAG rod. An oscillator is constructed, based on the results of the simulation, and it exhibits a world-high class continuous laser performance of a 1.8kW output and 13% efficiency. The record of 13% efficiency is five times higher than that achieved by the conventional lamp-driven YAG laser device. (translated by NEDO)

  8. High temperature semiconductor diode laser pumps for high energy laser applications

    Science.gov (United States)

    Campbell, Jenna; Semenic, Tadej; Guinn, Keith; Leisher, Paul O.; Bhunia, Avijit; Mashanovitch, Milan; Renner, Daniel

    2018-02-01

    Existing thermal management technologies for diode laser pumps place a significant load on the size, weight and power consumption of High Power Solid State and Fiber Laser systems, thus making current laser systems very large, heavy, and inefficient in many important practical applications. To mitigate this thermal management burden, it is desirable for diode pumps to operate efficiently at high heat sink temperatures. In this work, we have developed a scalable cooling architecture, based on jet-impingement technology with industrial coolant, for efficient cooling of diode laser bars. We have demonstrated 60% electrical-to-optical efficiency from a 9xx nm two-bar laser stack operating with propylene-glycolwater coolant, at 50 °C coolant temperature. To our knowledge, this is the highest efficiency achieved from a diode stack using 50 °C industrial fluid coolant. The output power is greater than 100 W per bar. Stacks with additional laser bars are currently in development, as this cooler architecture is scalable to a 1 kW system. This work will enable compact and robust fiber-coupled diode pump modules for high energy laser applications.

  9. Laser Plasma Instability Experiments with KrF Lasers

    National Research Council Canada - National Science Library

    Weaver, J. L; Oh, J; Afeyan, B; Phillips, L; Seely, J; Feldman, U; Brown, C; Karasik, , M; Serlin, V; Aglitskiy, Y; Mostovych, A. N

    2007-01-01

    ...) with a rep-rate system that has a per pulse laser energy well below 1 megajoule. Measurements of LPI using the Nike KrF laser are presented at and above intensities needed for the FTF (Ĩ2x1015 W/cm2...

  10. Laser cladding with powder

    NARCIS (Netherlands)

    Schneider, M.F.; Schneider, Marcel Fredrik

    1998-01-01

    This thesis is directed to laser cladding with powder and a CO2 laser as heat source. The laser beam intensity profile turned out to be an important pa6 Summary rameter in laser cladding. A numerical model was developed that allows the prediction of the surface temperature distribution that is

  11. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.

    2007-01-01

    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  12. Development of laser technology in Research Center of Laser Fusion

    International Nuclear Information System (INIS)

    Zheng Wanguo; Deng Ying; Zhou Wei

    2013-01-01

    This paper reviews the progress in the construction of SG-Ⅲ laser facility, integrated Testbed and XG-Ⅲ laser facility and that in the upgrade of the prototype of SG-Ⅲ, and the development in assembling and installing technology, and the achievements in maintaining cleanliness project and metrology in Laser Fusion Research Center, China Academy of Engineering Physics in China in 2012. (authors)

  13. Laser systems configured to output a spectrally-consolidated laser beam and related methods

    Science.gov (United States)

    Koplow, Jeffrey P [San Ramon, CA

    2012-01-10

    A laser apparatus includes a plurality of pumps each of which is configured to emit a corresponding pump laser beam having a unique peak wavelength. The laser apparatus includes a spectral beam combiner configured to combine the corresponding pump laser beams into a substantially spatially-coherent pump laser beam having a pump spectrum that includes the unique peak wavelengths, and first and second selectively reflective elements spaced from each other to define a lasing cavity including a lasing medium therein. The lasing medium generates a plurality of gain spectra responsive to absorbing the pump laser beam. Each gain spectrum corresponds to a respective one of the unique peak wavelengths of the substantially spatially-coherent pump laser beam and partially overlaps with all other ones of the gain spectra. The reflective elements are configured to promote emission of a laser beam from the lasing medium with a peak wavelength common to each gain spectrum.

  14. Laser ablation of UHMWPE-polyethylene by 438 nm high energy pulsed laser

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, L.; Gammino, S.; Mezzasalma, A.M.; Visco, A.M.; Badziak, J.; Parys, P.; Wolowski, J.; Woryna, E.; Krasa, J.; Laska, L.; Pfeifer, M.; Rohlena, K.; Boody, F.P

    2004-04-15

    Pulsed laser ablation of ultra-high-molecular-weight-polyethylene (UHMWPE) is investigated at Prague Asterix Laser System (PALS) Laboratory. The high ablation yield as a function of laser energy is presented at 438 nm laser wavelength. The mechanisms of the polymer ablation are studied on the base of ''in situ'' analysis, such as mass quadrupole spectrometry and time-of-flight measurements, and ''ex situ'' analysis, such as SEM investigations and Raman spectroscopy. Results show that the laser irradiation induces a strong polymer dehydrogenation and molecular emission due to different C{sub x}H{sub y} groups having high kinetic energy and high charge state. At a laser pulse energy of 150 J the H{sup +}, C{sup n+} ions (n=1 to 6) are emitted from the plasma with velocities of the order of 10{sup 8} cm/s, while the C{sub x}H{sub y} groups and the carbon clusters, detected up to C{sub 16}, have a velocity about one or two order magnitude lower. The laser ablation process produces a deep crater in the polymer, which depth depends on the laser pulse energy and it is of the order of 500 {mu}m. The crater volume increases with the laser pulse energy. Results demonstrated that the laser radiation modifies the polymer chains because dehydrogenated material and carbon-like structures are detected in the crater walls and in the bottom of the crater, respectively. A comparison of the experimental results with the data available in literature is presented and discussed.

  15. Double pulse laser ablation and plasma: Laser induced breakdown spectroscopy signal enhancement

    International Nuclear Information System (INIS)

    Babushok, V.I.; DeLucia, F.C.; Gottfried, J.L.; Munson, C.A.; Miziolek, A.W.

    2006-01-01

    A review of recent results of the studies of double laser pulse plasma and ablation for laser induced breakdown spectroscopy applications is presented. The double pulse laser induced breakdown spectroscopy configuration was suggested with the aim of overcoming the sensitivity shortcomings of the conventional single pulse laser induced breakdown spectroscopy technique. Several configurations have been suggested for the realization of the double pulse laser induced breakdown spectroscopy technique: collinear, orthogonal pre-spark, orthogonal pre-heating and dual pulse crossed beam modes. In addition, combinations of laser pulses with different wavelengths, different energies and durations were studied, thus providing flexibility in the choice of wavelength, pulse width, energy and pulse sequence. The double pulse laser induced breakdown spectroscopy approach provides a significant enhancement in the intensity of laser induced breakdown spectroscopy emission lines up to two orders of magnitude greater than a conventional single pulse laser induced breakdown spectroscopy. The double pulse technique leads to a better coupling of the laser beam with the plasma plume and target material, thus providing a more temporally effective energy delivery to the plasma and target. The experimental results demonstrate that the maximum effect is obtained at some optimum separation delay time between pulses. The optimum value of the interpulse delay depends on several factors, such as the target material, the energy level of excited states responsible for the emission, and the type of enhancement process considered. Depending on the specified parameter, the enhancement effects were observed on different time scales ranging from the picosecond time level (e.g., ion yield, ablation mass) up to the hundred microsecond level (e.g., increased emission intensity for laser induced breakdown spectroscopy of submerged metal target in water). Several suggestions have been proposed to explain

  16. Laser safety and practice

    International Nuclear Information System (INIS)

    Low, K.S.

    1995-01-01

    Lasers are finding increasing routine applications in many areas of science, medicine and industry. Though laser radiation is non-ionizing in nature, the usage of high power lasers requires specific safety procedures. This paper briefly outlines the properties of laser beams and various safety procedures necessary in their handling and usage. (author)

  17. Laser Applications in Orthodontics

    Science.gov (United States)

    Heidari, Somayeh; Torkan, Sepideh

    2013-01-01

    A laser is a collimated single wavelength of light which delivers a concentrated source of energy. Soon after different types of lasers were invented, investigators began to examine the effects of different wavelengths of laser energy on oral tissues, routine dental procedures and experimental applications. Orthodontists, along with other specialist in different fields of dentistry, can now benefit from several different advantages that lasers provide during the treatment process, from the beginning of the treatment, when separators are placed, to the time of resin residues removal from the tooth surface at the end of orthodontic treatment. This article outlines some of the most common usages of laser beam in orthodontics and also provides a comparison between laser and other conventional method that were the standard of care prior to the advent of laser in this field. PMID:25606324

  18. Lasers in materials science

    CERN Document Server

    Ossi, Paolo; Zhigilei, Leonid

    2014-01-01

    This book covers various aspects of lasers in materials science, including a comprehensive overview on basic principles of laser-materials interactions and applications enabled by pulsed laser systems.  The material is organized in a coherent way, providing the reader with a harmonic architecture. While systematically covering the major current and emerging areas of lasers processing applications, the Volume provides examples of targeted modification of material properties achieved through careful control of the processing conditions and laser irradiation parameters. Special emphasis is placed on specific strategies aimed at nanoscale control of material structure and properties to match the stringent requirements of modern applications.  Laser fabrication of novel nanomaterials, which expands to the domains of photonics, photovoltaics, sensing, and biomedical applications, is also discussed in the Volume. This book assembles chapters based on lectures delivered at the Venice International School on Lasers...

  19. Laser-powered lunar base

    International Nuclear Information System (INIS)

    Costen, R.; Humes, D.H.; Walker, G.H.; Williams, M.D.; Deyoung, R.J.

    1989-01-01

    The objective was to compare a nuclear reactor-driven Sterling engine lunar base power source to a laser-to-electric converter with orbiting laser power station, each providing 1 MW of electricity to the lunar base. The comparison was made on the basis of total mass required in low-Earth-orbit for each system. This total mass includes transportation mass required to place systems in low-lunar orbit or on the lunar surface. The nuclear reactor with Sterling engines is considered the reference mission for lunar base power and is described first. The details of the laser-to-electric converter and mass are discussed. The next two solar-driven high-power laser concepts, the diode array laser or the iodine laser system, are discussed with associated masses in low-lunar-orbit. Finally, the payoff for laser-power beaming is summarized

  20. Fast-electron-relaxation measurement for laser-solid interaction at relativistic laser intensities

    International Nuclear Information System (INIS)

    Chen, H.; Shepherd, R.; Chung, H. K.; Kemp, A.; Hansen, S. B.; Wilks, S. C.; Ping, Y.; Widmann, K.; Fournier, K. B.; Beiersdorfer, P.; Dyer, G.; Faenov, A.; Pikuz, T.

    2007-01-01

    We present measurements of the fast-electron-relaxation time in short-pulse (0.5 ps) laser-solid interactions for laser intensities of 10 17 , 10 18 , and 10 19 W/cm 2 , using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. We find that the laser coupling to hot electrons increases as the laser intensity becomes relativistic, and that the thermalization of fast electrons occurs over time scales on the order of 10 ps at all laser intensities. The experimental data are analyzed using a combination of models that include Kα generation, collisional coupling, and plasma expansion

  1. Research of time fiducial and imaging VISAR laser for Shenguang-III laser facility

    Science.gov (United States)

    Zhang, Rui; Wang, Zhenguo; Tian, Xiaocheng; Zhou, Dandan; Zhu, Na; Wang, Jianjun; Li, Mingzhong; Xu, Dangpeng; Dang, Zhao; Hu, Dongxia; Zhu, Qihua; Zheng, Wanguo; Wang, Feng

    2015-10-01

    Time fiducial laser is an important tool for the precise measurement in high energy density physics experiments. The VISAR probe laser is also vital for shock wave diagnostics in ICF experiments. Here, time fiducial laser and VISAR light were generated from one source on SG-III laser facility. After generated from a 1064-nm DFB laser, the laser is modulated by an amplitude modulator driven by 10 GS/s arbitrary waveform generator. Using time division multiplexing technology, the ten-pulse time fiducial laser and the 20-ns VISAR pulse were split by a 1×2 multiplexer and then chosen by two acoustic optic modulators. Using the technique, cost of the system was reduced. The technologies adopted in the system also include pulse polarization stabilization, high precision fiber coupling and energy transmission. The time fiducial laser generated synchronized 12-beam 2ω and 4-beam 3ω laser, providing important reference marks for different detectors and making it convenient for the analysis of diagnostic data. After being amplified by fiber amplifiers and Nd:YAG rod amplifiers, the VISAR laser pulse was frequency-converted to 532-nm pulse by a thermally controlled LBO crystal with final output energy larger than 20 mJ. Finally, the green light was coupled into a 1-mm core diameter, multimode fused silica optical fiber and propagated to the imaging VISAR. The VISAR laser has been used in the VISAR diagnostic physics experiments. Shock wave loading and slowdown processes were measured. Function to measure velocity history of shock wave front movement in different kinds of materials was added to the SG-III laser facility.

  2. Laser antisepsis of Phorphyromonas gingivalis in vitro with dental lasers

    Science.gov (United States)

    Harris, David M.

    2004-05-01

    It has been shown that both pulsed Nd:YAG (1064nm) and continuous diode (810nm) dental lasers kill pathogenic bacteria (laser antisepsis), but a quantitative method for determining clinical dosimetry does not exist. The purpose of this study was to develop a method to quantify the efficacy of ablation of Porphyromonas gingivalis (Pg) in vitro for two different lasers. The ablation thresholds for the two lasers were compared in the following manner. The energy density was measured as a function of distance from the output of the fiber-optic delivery system. Pg cultures were grown on blood agar plates under standard anaerobic conditions. Blood agar provides an approximation of gingival tissue for the wavelengths tested in having hemoglobin as a primary absorber. Single pulses (Nd:YAG: 100- Œs diode: 100-msec) of laser energy were delivered to Pg colonies and the energy density was increased until the appearance of a small plume was observed coincident with a laser pulse. The energy density at this point defines the ablation threshold. Ablation thresholds to a single pulse were determined for both Pg and for blood agar alone. The large difference in ablation thresholds between the pigmented pathogen and the host matrix for pulsed-Nd:YAG represented a significant therapeutic ratio and Pg was ablated without visible effect on the blood agar. Near threshold the 810-nm diode laser destroyed both the pathogen and the gel. Clinically, the pulsed Nd:YAG may selectively destroy pigmented pathogens leaving the surrounding tissue intact. The 810-nm diode laser may not demonstrate this selectivity due to its longer pulse length and greater absorption by hemoglobin.

  3. Latest development of laser cutting

    OpenAIRE

    Wetzig, Andreas; Herwig, Patrick; Hauptmann, Jan; Goppold, Cindy; Baumann, Robert; Fürst, Andreas; Rose, Michael; Pinder, Thomas; Mahrle, Achim; Beyer, Eckhard

    2016-01-01

    Laser cutting was one of the first applications of laser material processing. Today, laser cutting is the most widespread application among laser material processing besides laser marking. Meanwhile, nearly each material can be cut by means of a laser, in particular since ultra short pulse lasers are available in the power range of up to 100 W. The to be cut material can come with thicknesses from a few microns till tens of millimeters as flat stock or as free form shapes. The paper will conc...

  4. High power lasers

    CERN Document Server

    Niku-Lari, A

    1989-01-01

    The use of lasers for the working and treatment of materials is becoming increasingly common in industry. However, certain laser applications, for example, in welding, cutting and drilling, are more widely exploited than others. Whilst the potential of lasers for the surface treatment of metals is well recognised, in practice, this particular application is a relative newcomer. The 24 papers in this volume present the latest research and engineering developments in the use of lasers for processes such as surface melting, surface alloying and cladding, and machining, as well as discussing th

  5. Performance of a 200-J KrF laser amplifier for laser fusion research

    International Nuclear Information System (INIS)

    Owadano, Y.; Okuda, I.; Tanimoto, M.; Kasai, T.; Matsumoto, Y.; Yaoita, A.; Nemoto, F.; Komeiji, S.; Yano, M.

    1986-01-01

    An e-beam-pumped KrF laser has been developed as a middle-stage amplifier of a 1-kJ system for laser fusion research. The laser consists of one Marx generator (1MV, 11kJ), two PFLs (4.6 Ω, 100ns) with laser triggered output switches, two e-beam diodes (10 X 60 cm/sup 2/), and a laser cell (20- X 20- X 60-cm/sup 3/ active volume). Two e-beams are injected into the cell through carbon-sprayed Kapton anode and pressure foils. Up to now, a 120-J (70-ns) laser pulse has been generated with a 90% output coupling flat-flat resonator at 80% voltage operation. Overall efficiency is 1.5% in this case. A series of experiments has been performed with the laser to measure gain characteristics of a Kr-rich mixture, which is predicted to be more efficient than a normal Ar mixture in a high-laser-intensity region (>10 MW cm/sup -2/). An injection-locked oscillator mode was used to obtain a well-defined high-intensity laser beam, and a saturated intracavity intensity was measured

  6. Fluorescence-pumped photolytic gas laser system for a commercial laser fusion power plant

    International Nuclear Information System (INIS)

    Monsler, M.J.

    1977-01-01

    The first results are given for the conceptual design of a short-wavelength gas laser system suitable for use as a driver (high average power ignition source) for a commercial laser fusion power plant. A comparison of projected overall system efficiencies of photolytically excited oxygen, sulfur, selenium and iodine lasers is described, using a unique windowless laser cavity geometry which will allow scaling of single amplifier modules to 125 kJ per aperture for 1 ns pulses. On the basis of highest projected overall efficiency, a selenium laser is chosen for a conceptual power plant fusion laser system. This laser operates on the 489 nm transauroral transition of selenium, excited by photolytic dissociation of COSe by ultraviolet fluorescence radiation. Power balances and relative costs for optics, electrical power conditioning and flow conditioning of both the laser and fluorescer gas streams are discussed for a system with the following characteristics: 8 operating modules, 2 standby modules, 125 kJ per module, 1.4 pulses per second, 1.4 MW total average power. The technical issues of scaling visible and near-infrared photolytic gas laser systems to this size are discussed

  7. Laser lipolysis: skin tightening in lipoplasty using a diode laser.

    Science.gov (United States)

    Wolfenson, Moisés; Hochman, Bernardo; Ferreira, Lydia Massako

    2015-05-01

    New devices have been developed for surgical repair of deformities caused by localized fat deposits associated with skin laxity. The use of these devices requires the adoption of safety parameters. The aim of this study was to investigate skin tightening by laser lipolysis, using a dual-wavelength diode laser. This prospective, cross-sectional study was conducted between June of 2008 and July of 2010 with 41 consecutive patients who underwent laser lipolysis to correct contour deformities. Laser lipolysis was performed with a diode laser operating at two wavelengths (924 and 975 nm) controlled independently, and using three different tip lengths, allowing treatment of small, medium, and large areas of adipose tissue. The procedure was performed under local anesthesia in a surgical setting. To calculate the optimal cumulative energy, a total energy dose of 5 kJ/10 × 10-cm skin area was used as a safety parameter to prevent treatment complications. The circumferences of body regions were measured preoperatively, immediately after surgery, and 90 days later. Measurements were compared using the Wilcoxon test at a significance level of 0.05 (p Laser lipolysis results in progressive skin tightening over time. Therapeutic, IV.

  8. Theoretical and experimental aspects of laser cutting with a direct diode laser

    Science.gov (United States)

    Costa Rodrigues, G.; Pencinovsky, J.; Cuypers, M.; Duflou, J. R.

    2014-10-01

    Recent developments in beam coupling techniques have made it possible to scale up the power of diode lasers with a laser beam quality suitable for laser cutting of metal sheets. In this paper a prototype of a Direct Diode Laser (DDL) source (BPP of 22 mm-mrad) is analyzed in terms of efficiency and cut performance and compared with two established technologies, CO2 and fiber lasers. An analytical model based on absorption calculations is used to predict the performance of the studied laser source with a good agreement with experimental results. Furthermore results of fusion cutting of stainless steel and aluminium alloys as well as oxygen cutting of structural steel are presented, demonstrating that industrial relevant cutting speeds with high cutting quality can now be achieved with DDL.

  9. Note: Digital laser frequency auto-locking for inter-satellite laser ranging.

    Science.gov (United States)

    Luo, Yingxin; Li, Hongyin; Yeh, Hsien-Chi

    2016-05-01

    We present a prototype of a laser frequency auto-locking and re-locking control system designed for laser frequency stabilization in inter-satellite laser ranging system. The controller has been implemented on field programmable gate arrays and programmed with LabVIEW software. The controller allows initial frequency calibrating and lock-in of a free-running laser to a Fabry-Pérot cavity. Since it allows automatic recovery from unlocked conditions, benefit derives to automated in-orbit operations. Program design and experimental results are demonstrated.

  10. Note: Digital laser frequency auto-locking for inter-satellite laser ranging

    International Nuclear Information System (INIS)

    Luo, Yingxin; Yeh, Hsien-Chi; Li, Hongyin

    2016-01-01

    We present a prototype of a laser frequency auto-locking and re-locking control system designed for laser frequency stabilization in inter-satellite laser ranging system. The controller has been implemented on field programmable gate arrays and programmed with LabVIEW software. The controller allows initial frequency calibrating and lock-in of a free-running laser to a Fabry-Pérot cavity. Since it allows automatic recovery from unlocked conditions, benefit derives to automated in-orbit operations. Program design and experimental results are demonstrated.

  11. Note: Digital laser frequency auto-locking for inter-satellite laser ranging

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yingxin; Yeh, Hsien-Chi, E-mail: yexianji@mail.hust.edu.cn [MOE Key Laboratory of Fundamental Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Li, Hongyin [MOE Key Laboratory of Fundamental Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Automation, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2016-05-15

    We present a prototype of a laser frequency auto-locking and re-locking control system designed for laser frequency stabilization in inter-satellite laser ranging system. The controller has been implemented on field programmable gate arrays and programmed with LabVIEW software. The controller allows initial frequency calibrating and lock-in of a free-running laser to a Fabry-Pérot cavity. Since it allows automatic recovery from unlocked conditions, benefit derives to automated in-orbit operations. Program design and experimental results are demonstrated.

  12. CO2 laser and plasma microjet process for improving laser optics

    Science.gov (United States)

    Brusasco, Raymond M.; Penetrante, Bernardino M.; Butler, James A.; Grundler, Walter; Governo, George K.

    2003-09-16

    A optic is produced for operation at the fundamental Nd:YAG laser wavelength of 1.06 micrometers through the tripled Nd:YAG laser wavelength of 355 nanometers by the method of reducing or eliminating the growth of laser damage sites in the optics by processing the optics to stop damage in the optics from growing to a predetermined critical size. A system is provided of mitigating the growth of laser-induced damage in optics by virtue of very localized removal of glass and absorbing material.

  13. Laser wakefield acceleration

    International Nuclear Information System (INIS)

    Esarey, E.; Ting, A.; Sprangle, P.

    1989-01-01

    The laser wakefield accelerator (LWFA) is a novel plasma based electron acceleration scheme which utilizes a relativistic optical guiding mechanism for laser pulse propagation. In the LWFA, a short, high power, single frequency laser pulse is propagated through a plasma. As the laser pulse propagates, its radial and axial ponderomotive forces nonresonantly generate large amplitude plasma waves (wakefields) with a phase velocity equal to the group velocity of the pulse. A properly phased electron bunch may then be accelerated by the axial wakefield and focused by the transverse wakefield. Optical guiding of the laser pulse in the plasma is necessary in order to achieve high energies in a single stage of acceleration. At sufficiently high laser powers, optical guiding may be achieved through relativistic effects associated with the plasma electrons. Preliminary analysis indicates that this scheme may overcome some of the difficulties present in the plasma beat wave accelerator and in the plasma wakefield accelerator. Analytical and numerical calculations are presented which study both laser pulse propagation within a plasma as well as the subsequent generation of large amplitude plasma waves. In addition, the generation of large amplitude plasma waves in regimes where the plasma waves become highly nonlinear is examined

  14. Synergistic skin heat shock protein expression in response to combined laser treatment with a diode laser and ablative fractional lasers.

    Science.gov (United States)

    Paasch, Uwe; Sonja, Grunewald; Haedersdal, Merete

    2014-06-01

    Diode laser-based skin heating has been shown to minimise scars by interfering with wound healing responses through the induction of heat shock proteins (HSP). HSP are also induced after ablative fractional laser (AFXL) wound healing. AFXL itself is highly recommended for scar treatment. Therefore, the sequential combination of both modalities may produce superior outcomes. The aim of this study was to examine the pretreatment effects of a diode laser before AFXL on wound healing responses in terms of HSP up-regulation in an in vitro model. Immediate responses and responses on days 1, 3 or 6 post-procedure were studied in an in vitro porcine skin model (n = 240). Untreated samples served as control. Immunohistochemical investigation (Hsp70) was performed in all untreated controls, diode laser-, AFXL-, and in diode laser + AFXL-treated samples. Hsp70 was shown to be up-regulated by all interventions between days 1 and 6 after interventions. The largest effect was caused by the combination of a diode laser and an AFXL procedure. Diode laser exposure induces a skin HSP response that can be further enhanced by sequential AFXL treatment. Clinical studies are necessary to investigate the dose response of HSP on scar formation and refine suitable laser exposure settings.

  15. Development and characterization of femtosecond laser driven soft x-ray lasers

    International Nuclear Information System (INIS)

    Bettaibi, I.

    2005-06-01

    Coherent soft x-ray sources have an important potential for scientific, medical and industrial applications. The development of high intensity laser systems allowed the realization of new coherent and fast soft x-ray sources like high order harmonic generation and soft x-ray lasers. These sources are compact, cheaper than traditional sources such as synchrotrons, and are thus interesting. This thesis presents the study of a new soft x-ray laser pumped by a femto-second laser beam working at 10 Hz. The circularly polarized ultra intense laser is longitudinally focused in a cell filled with xenon or krypton, to obtain the amplification of two lasing lines at 41.8 nm and 32.8 nm in Pd-like xenon and Ni-like krypton respectively. We carry out an experimental and numerical study of the source to understand the importance of different parameters such as the laser intensity and polarization, the gas pressure and the cell length. We have also spatially and temporally characterized the soft x-ray laser beam. To compensate the refraction of the driving laser we have investigated guiding techniques consisting in creating a plasma channel by electric discharge or using the multiple reflections of the driving laser on the internal walls of the dielectric tubes of sapphire or glass. A spectacular improvement of the source performances has been observed in both cases. Finally, we present a preliminary study on a different x-ray scheme: the inner shell photo pumping of neutral atoms. We have developed an optical system, which should create the appropriate conditions for the realisation of short wavelength x-ray amplifier. (author)

  16. New photoionization lasers pumped by laser-induced plasma radiation

    International Nuclear Information System (INIS)

    Hube, M.; Dieckmann, M.; Beigang, R.; Welling, H.; Wellegehausen, B.

    1988-01-01

    Innershell photoionization of atomic gases and vapors by soft x rays from a laser-produced plasma is a potential method for making lasers at short wavelengths. Normally, in such experiments only a single plasma spot or plasma line is created for the excitation. This gives high excitation rates but only a short excitation length. At high excitation rates detrimental influences, such as amplified spontaneous emission, optical saturation, or quenching processes, may decrease or even destroy a possible inversion. Therefore, it seems to be more favorable to use a number of separated plasma spots with smaller excitation rates and larger excitation lengths. As a test, a three-plasma spot device was constructed and used in the well-known Cd-photoionization laser at 442 nm. With a 600-mJ Nd:YAH laser (pulse length, 8 ns) for plasma production, output energies up to 300 μJ have been measured, which is more than a doubling of so far obtained data. On innershell excitation, levels may be populated that allow direct lasers as in the case of Cd or that are metastable and cannot be directly coupled to lower levels. In this case modifications in the excitation process are necessary. Such modifications may be an optical pump process in the atom prior to the innershell photoionization or an optical pump process (population transfer process) after the innershell ionization, leading to Raman or anti-Stokes Raman-type laser emissions. With these techniques and the developed multiplasma spot excitation device a variety of new laser emissions in K and Cs ions have been achieved which are indicated in the level schemes

  17. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

  18. Laser induced nuclear reactions

    International Nuclear Information System (INIS)

    Ledingham, Ken; McCanny, Tom; Graham, Paul; Fang Xiao; Singhal, Ravi; Magill, Joe; Creswell, Alan; Sanderson, David; Allott, Ric; Neely, David; Norreys, Peter; Santala, Marko; Zepf, Matthew; Watts, Ian; Clark, Eugene; Krushelnick, Karl; Tatarakis, Michael; Dangor, Bucker; Machecek, Antonin; Wark, Justin

    1998-01-01

    Dramatic improvements in laser technology since 1984 have revolutionised high power laser technology. Application of chirped-pulse amplification techniques has resulted in laser intensities in excess of 10 19 W/cm 2 . In the mid to late eighties, C. K. Rhodes and K. Boyer discussed the possibility of shining laser light of this intensity onto solid surfaces and to cause nuclear transitions. In particular, irradiation of a uranium target could induce electro- and photofission in the focal region of the laser. In this paper it is shown that μCi of 62 Cu can be generated via the (γ,n) reaction by a laser with an intensity of about 10 19 Wcm -2

  19. Temperature stabilization of injection lasers

    International Nuclear Information System (INIS)

    Albanese, A.

    1987-01-01

    Apparatus which stabilizes the temperature, and thereby the output wavelength, of an injection laser. Means monitor the laser terminal voltage across a laser and derive a voltage therefrom which is proportional to the junction voltage of the laser. Means compares the voltage to a reference value from source and a temperature controller adjusts the laser temperature in response to the results of the comparison. Further embodiments of the present invention vary the output wavelength of the laser by varying the reference value from source against which the laser junction voltage is compared. (author)

  20. IceBridge Riegl Laser Altimeter L1B Time-Tagged Laser Ranges

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Riegl Laser Altimeter L1B Time-Tagged Laser Ranges (ILUTP1B) data set contains laser ranges, returned pulses, and deviation for returned pulses in...

  1. New-laser research and development

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Two new-laser research efforts were initiated during the reporting period; the chemically pumped iodine laser and HgXe exciplex excitation by electric discharge. The chemically pumped iodine laser was recently discovered by personnel at the Air Force Weapons Laboratory. The laser offers exciting possibilities as an ICF driver because it does not require a capital-intensive pulse power source to drive it, and up to 10% efficiency may be possible. Modeling studies of the laser are in progress and its potential as a high-average power laser seems to be very favorable at this time. The HgXe exciplex radiates in a band centered at 265 nm. This system is being studied because it could be used to pump an iodine laser. Its potential as a high-power laser candidate will be assessed. An advanced oscillator system based upon a microprocessor-controlled Nd:YAG-pumped pulsed dye laser is being developed so that it can be used as the front end of new laser-fusion lasers and utilized in testing and making germane laser amplifier measurements of candidate laser systems for the wavelength region of 4000 A to 8000 A and extended range with frequency doubling and mixing. The operating requirements of the oscillator system include long-term stability, high reliability, absolute wavelength calibration and control, tunability, hands-off operation, and variable pulse width generation in the nanosecond regime

  2. D2O laser pumped by an injection-locked CO2 laser for ion-temperature measurements

    International Nuclear Information System (INIS)

    Okada, Tatsuo; Ohga, Tetsuaki; Yokoo, Masakazu; Muraoka, Katsunori; Akazaki, Masanori.

    1986-01-01

    The cooperative Thomson scattering method is one of the various new techniques proposed for measuring the temperature of ions in nuclear fusion critical plasma, for which a high-performance FIR laser pumped by an injection-locked CO 2 laser is required. This report deals with D 2 O laser with a wavelength of 385 μm which is pumped by injection-locked single-mole TEA CO 2 laser composed of a driver laser and an output-stage laser. A small-sized automatic pre-ionization type laser is employed for the driver. The resonator of the driver laser consists of a plane grating of littrow arrangement and ZnSe plane output mirrors with reflection factor of 50 %. An aperture and ZnSe etalon are inserted in the resonator to produce single transverse- and longitudinal-mode oscillation, respectively. The output-stage laser is also of the automatic pre-ionization type. Theoretically, an injection power of 0.1 pW/mm 3 is required for a CO 2 laser. Single-mode oscillation of several hundred nW/mm 3 can be produced by the CO 2 laser used in this study. Tuning of the output-stage laser is easily controlled by the driver laser. High stability of the injection-locked operation is demonstrated. CO 2 laser beam is introduced into the D 2 O laser through a KCl window to excite D 2 O laser beam in the axial direction. Input and output characteristics of the D 2 O laser are shown. Also presented are typical pulse shapes from the D 2 O laser pumped by a free-running CO 2 laser pulse or by an injection-locked single-mode CO 2 laser pulse. (Nogami, K.)

  3. Diode lasers and arrays

    International Nuclear Information System (INIS)

    Streifer, W.

    1988-01-01

    This paper discusses the principles of operation of III-V semiconductor diode lasers, the use of distributed feedback, and high power laser arrays. The semiconductor laser is a robust, miniature, versatile device, which directly converts electricity to light with very high efficiency. Applications to pumping solid-state lasers and to fiber optic and point-to-point communications are reviewed

  4. Trends in laser micromachining

    Science.gov (United States)

    Gaebler, Frank; van Nunen, Joris; Held, Andrew

    2016-03-01

    Laser Micromachining is well established in industry. Depending on the application lasers with pulse length from μseconds to femtoseconds and wavelengths from 1064nm and its harmonics up to 5μm or 10.6μm are used. Ultrafast laser machining using pulses with pico or femtosecond duration pulses is gaining traction, as it offers very precise processing of materials with low thermal impact. Large-scale industrial ultrafast laser applications show that the market can be divided into various sub segments. One set of applications demand low power around 10W, compact footprint and are extremely sensitive to the laser price whilst still demanding 10ps or shorter laser pulses. A second set of applications are very power hungry and only become economically feasible for large scale deployments at power levels in the 100+W class. There is also a growing demand for applications requiring fs-laser pulses. In our presentation we would like to describe these sub segments by using selected applications from the automotive and electronics industry e.g. drilling of gas/diesel injection nozzles, dicing of LED substrates. We close the presentation with an outlook to micromachining applications e.g. glass cutting and foil processing with unique new CO lasers emitting 5μm laser wavelength.

  5. Quality and performance of laser cutting with a high power SM fiber laser

    DEFF Research Database (Denmark)

    Kristiansen, Morten; Selchau, Jacob; Olsen, F. O.

    2013-01-01

    The introduction of high power single mode fiber lasers allows for a beam of high power and a good beam quality factor (M2 ” 1.2), compared to the multimode fiber lasers often utilised in macro laser metal cutting. This paper describes fundamental studies of macro laser metal cutting with a singl...

  6. Laser Light: Using Laser Refractometry to Determine Concentration.

    Science.gov (United States)

    Gauger, Robert

    1995-01-01

    Laser refractometry is a science-technology-based activity that requires students to manipulate a variety of equipment, tools, materials, and critical-thinking skills. Students use a laser to measure the percent of glucose in a solution by calibrating the system, taking measurements, and computing the concentration. (MKR)

  7. Laser experimental system as teaching aid for demonstrating basic phenomena of laser feedback

    International Nuclear Information System (INIS)

    Xu, Ling; Zhao, Shijie; Zhang, Shulian

    2015-01-01

    An experimental laser teaching system is developed to demonstrate laser feedback phenomena, which bring great harm to optical communication and benefits to precision measurement. The system consists of an orthogonally polarized He-Ne laser, a feedback mirror which reflects the laser output light into the laser cavity, and an optical attenuator which changes the intensity of the feedback light. As the feedback mirror is driven by a piezoelectric ceramic, the attenuator is adjusted and the feedback mirror is tilted, the system can demonstrate many basic laser feedback phenomena, including weak, moderate and strong optical feedback, multiple feedback and polarization flipping. Demonstrations of these phenomena can give students a better understanding about the intensity and polarization of lasers. The system is well designed and assembled, simple to operate, and provides a valuable teaching aid at an undergraduate level. (paper)

  8. Micromachining with copper lasers

    Science.gov (United States)

    Knowles, Martyn R. H.; Bell, Andy; Foster-Turner, Gideon; Rutterford, Graham; Chudzicki, J.; Kearsley, Andrew J.

    1997-04-01

    In recent years the copper laser has undergone extensive development and has emerged as a leading and unique laser for micromachining. The copper laser is a high average power (10 - 250 W), high pulse repetition rate (2 - 32 kHz), visible laser (511 nm and 578 nm) that produces high peak power (typically 200 kW), short pulses (30 ns) and very good beam quality (diffraction limited). This unique set of laser parameters results in exceptional micro-machining in a wide variety of materials. Typical examples of the capabilities of the copper laser include the drilling of small holes (10 - 200 micrometer diameter) in materials as diverse as steel, ceramic, diamond and polyimide with micron precision and low taper (less than 1 degree) cutting and profiling of diamond. Application of the copper laser covers the electronic, aerospace, automotive, nuclear, medical and precision engineering industries.

  9. ORION laser target diagnostics

    International Nuclear Information System (INIS)

    Bentley, C. D.; Edwards, R. D.; Andrew, J. E.; James, S. F.; Gardner, M. D.; Comley, A. J.; Vaughan, K.; Horsfield, C. J.; Rubery, M. S.; Rothman, S. D.; Daykin, S.; Masoero, S. J.; Palmer, J. B.; Meadowcroft, A. L.; Williams, B. M.; Gumbrell, E. T.; Fyrth, J. D.; Brown, C. R. D.; Hill, M. P.; Oades, K.

    2012-01-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  10. ORION laser target diagnostics.

    Science.gov (United States)

    Bentley, C D; Edwards, R D; Andrew, J E; James, S F; Gardner, M D; Comley, A J; Vaughan, K; Horsfield, C J; Rubery, M S; Rothman, S D; Daykin, S; Masoero, S J; Palmer, J B; Meadowcroft, A L; Williams, B M; Gumbrell, E T; Fyrth, J D; Brown, C R D; Hill, M P; Oades, K; Wright, M J; Hood, B A; Kemshall, P

    2012-10-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  11. Laser safety in dentistry

    Science.gov (United States)

    Wigdor, Harvey A.

    1997-05-01

    One of the major causes of anxiety in the dental clinic is the dental handpiece. Because dentists wish to provide a method which can replace the drill there has often been a premature use of the laser in dentistry. Various lasers have been introduced into the clinic before research has shown the laser used is of clinical benefit. Any new treatment method must not compromise the health of the patient being treated. Thus a method of evaluating the clinical abilities of dentists and their understanding the limitations of the laser used must be developed. Dentist must be trained in the basic interaction of the laser on oral tissues. The training has to concentrate on the variation of the laser wavelength absorption in the different tissues of the oral cavity. Because of the differences in the optical properties of these tissues great care must be exercised by practitioners using lasers on patients.

  12. Lasers in tattoo and pigmentation control: role of the PicoSure(®) laser system.

    Science.gov (United States)

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure(®) laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure(®) laser system for tattoo removal. A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal". A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure(®) laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments.

  13. Laser Therapy

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Laser Resurfacing Uses for Laser Resurfacing Learn more ...

  14. Performance of a high repetition pulse rate laser system for in-gas-jet laser ionization studies with the Leuven laser ion source LISOL

    International Nuclear Information System (INIS)

    Ferrer, R.; Sonnenschein, V.T.; Bastin, B.; Franchoo, S.; Huyse, M.; Kudryavtsev, Yu.; Kron, T.; Lecesne, N.; Moore, I.D.; Osmond, B.; Pauwels, D.; Radulov, D.; Raeder, S.; Rens, L.

    2012-01-01

    The laser ionization efficiency of the Leuven gas cell-based laser ion source was investigated under on- and off-line conditions using two distinctly different laser setups: a low-repetition rate dye laser system and a high-repetition rate Ti:sapphire laser system. A systematic study of the ion signal dependence on repetition rate and laser pulse energy was performed in off-line tests using stable cobalt and copper isotopes. These studies also included in-gas-jet laser spectroscopy measurements on the hyperfine structure of 63 Cu. A final run under on-line conditions in which the radioactive isotope 59 Cu (T 1/2 = 81.5 s) was produced, showed a comparable yield of the two laser systems for in-gas-cell ionization. However, a significantly improved time overlap by using the high-repetition rate laser system for in-gas-jet ionization was demonstrated by an increase of the overall duty cycle, and at the same time, pointed to the need for a better shaped atomic jet to reach higher ionization efficiencies.

  15. Laser Safety Inspection Criteria

    International Nuclear Information System (INIS)

    Barat, K

    2005-01-01

    A responsibility of the Laser Safety Officer (LSO) is to perform laser safety audits. The American National Standard Z136.1 Safe use of Lasers references this requirement in several sections: (1) Section 1.3.2 LSO Specific Responsibilities states under Hazard Evaluation, ''The LSO shall be responsible for hazards evaluation of laser work areas''; (2) Section 1.3.2.8, Safety Features Audits, ''The LSO shall ensure that the safety features of the laser installation facilities and laser equipment are audited periodically to assure proper operation''; and (3) Appendix D, under Survey and Inspections, it states, ''the LSO will survey by inspection, as considered necessary, all areas where laser equipment is used''. Therefore, for facilities using Class 3B and or Class 4 lasers, audits for laser safety compliance are expected to be conducted. The composition, frequency and rigueur of that inspection/audit rests in the hands of the LSO. A common practice for institutions is to develop laser audit checklists or survey forms. In many institutions, a sole Laser Safety Officer (LSO) or a number of Deputy LSO's perform these audits. For that matter, there are institutions that request users to perform a self-assessment audit. Many items on the common audit list and the associated findings are subjective because they are based on the experience and interest of the LSO or auditor in particular items on the checklist. Beam block usage is an example; to one set of eyes a particular arrangement might be completely adequate, while to another the installation may be inadequate. In order to provide more consistency, the National Ignition Facility Directorate at Lawrence Livermore National Laboratory (NIF-LLNL) has established criteria for a number of items found on the typical laser safety audit form. These criteria are distributed to laser users, and they serve two broad purposes: first, it gives the user an expectation of what will be reviewed by an auditor, and second, it is an

  16. Synchronisation of a femtosecond laser and a Q-switched laser to within 50 ps

    International Nuclear Information System (INIS)

    Katin, E V; Lozhkarev, V V; Palashov, O V; Khazanov, E A

    2003-01-01

    A Nd:YLF laser emitting 2-ns pulses synchronised with a femtosecond Cr:forsterite laser is built. The pulse duration and synchronisation are ensured by two Pockels cells, in which voltage pulses are synchronised with the femtosecond laser by fast emitter-coupled logic elements. One of the Pockels cells ensures Q-switching, while the other cuts a short pulse from a 15-ns Q-switched pulse. The experimental results show that the two-step scheme proposed for synchronisation of a Q-switched laser and a passively mode-locked laser provides quite simple and reliable synchronisation of these lasers with a jitter of a few tens of picoseconds. (control of laser radiation parameters)

  17. Introduction to laser technology

    CERN Document Server

    Hitz, C Breck; Hecht, Jeff; Hitz, C Breck; John Wiley & Sons

    2001-01-01

    Electrical Engineering Introduction to Laser Technology , Third Edition. Would you like to know how a laser works, and how it can be modified for your own specific tasks? This intuitive third edition-previously published as Understanding Laser Technology , First and Second Editions-introduces engineers, scientists, technicians, and novices alike to the world of modern lasers, without delving into the mathematical details of quantum electronics. It is the only introductory text on the market today that explains the underlying physics and engineering applicable to all lasers. A unique combinatio.

  18. The laser thermonuclear fusion

    International Nuclear Information System (INIS)

    Coutant, J.; Dautray, R.; Decroisette, M.; Watteau, J.P.

    1987-01-01

    Principle of the thermonuclear fusion by inertial confinement: required characteristics of the deuterium-tritium plasma and of the high power lasers to be used Development of high power lasers: active media used; amplifiers; frequency conversion; beam quality; pulse conditioning; existing large systems. The laser-matter interaction: collision and collective interaction of the laser radiation with matter; transport of the absorbed energy; heating and compression of deuterium-tritium; diagnoses and their comparison with the numerical simulation of the experiment; performances. Conclusions: difficulties to overcome; megajoule lasers; other energy source: particles beams [fr

  19. Laser Cutting, Development Trends

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    1999-01-01

    In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting...... of 3-dimensional shapes.The CO2-laser will also in the near future be the dominating laser source in the market, although the new developments in ND-YAG-lasers opens for new possibilities for this laser type....

  20. Coherent laser beam combining

    CERN Document Server

    Brignon, Arnaud

    2013-01-01

    Recently, the improvement of diode pumping in solid state lasers and the development of double clad fiber lasers have allowed to maintain excellent laser beam quality with single mode fibers. However, the fiber output power if often limited below a power damage threshold. Coherent laser beam combining (CLBC) brings a solution to these limitations by identifying the most efficient architectures and allowing for excellent spectral and spatial quality. This knowledge will become critical for the design of the next generation high-power lasers and is of major interest to many industrial, environme

  1. Lasers in Ophthalmology

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    In recent years,lasers have entered every fieldof medicine and especially so in ophthalmol-ogy.The scientific basis of lasers in ophthal-mology is based on three mechanisms:1.Photothermal effectLasers:argon,krypton,dye and diodeA thermal effect is generated when laserenergy is absorbed by pigment leading to in-creased vibration and therefore heat content.A

  2. Integrated Laser-Target Interaction Experiments on the RAL Petawatt Laser

    International Nuclear Information System (INIS)

    Patel, P. K.; Key, M. H.; Mackinnon, A. J.; Akli, K.; Berry, R.; Borghesi, M.; Brummit, P. A.; Chambers, D.; Clarke, R. J.; Damian, C.; Chen, H.; Eagleton, R.; Freeman, R.; Glenzer, S.; Gregori, G.; Heathcote, R.; Izumi, N.; Kar, S.; King, J. A.; Kock, J.; Kuba, J.; May, M.; Moon, S.; Neely, D.; Neville, D. R.; Nikroo, A.; Niles, A.; Pasley, J.; Patel, N.; Park, H. S.; Romagnani, L.; Shepherd, R.; Snavely, R. A.; Stephens, R.; Stoeckl, C.; Storm, M.; Theobald, W.; Van Maren, R.; Wilks, S. C.; Zhang, B.

    2005-01-01

    We report on two recent experimental campaigns performed on the new Petawatt laser at the Rutherford Appleton Laboratory in the UK.The laser has recently demonstrated performance characteristics of 400 J of laser energy being delivered on target in a sub 400 fs pulse, reaching a peak focal intensity on the order of 10''21 W/cm''2. The experiments covered multiplic areas of investigation including hot electron transport in planar foil and cone focus geometries, relativistic laser-solid interactions proton beam focusing and heating, and high energy K-alpha production and radiography. A somewhat novel approach was taken to the experiments in that all of the diagnostics required for the different areas of study were fielded simultaneously and operated on all shots. Thus, we were able to obtain extensive sets of measurements on a single-shot basis which provides significant benefit to our understanding of the laser-target interaction conditions and plasma properties. (Author)

  3. Femtosecond laser micromachining of sapphire capillaries for laser-wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Messner, Philipp; Delbos, Niels Matthias; Maier, Andreas R. [CFEL, Center for Free-Electron Laser Science, 22607 Hamburg (Germany); University of Hamburg, Institute of Experimental Physics, 22761 Hamburg (Germany); Calmano, Thomas [University of Hamburg, Institute of Experimental Physics, 22761 Hamburg (Germany)

    2015-07-01

    Laser-plasma accelerator are promising candidates to provide ultra-relativistic electron beams for compact light sources. One factor that limits the achievable electron beam energy in a laser plasma accelerator is the Rayleigh length of the driver laser, which dictates the length over which the electron beams can effectively be accelerated. To overcome this limitation lasers can be guided in a capillary waveguide to extend the acceleration length beyond the Rayleigh length. The production of waveguide structures on scales, that are suitable for plasma acceleration is very challenging. Here, we present experimental results from waveguide machining in sapphire crystals using a Clark MXR CPA 2010 laser with a wavelength of 775nm, 1KHZ repetition rate and a pulse duration of 160 fs. We discuss the effects of different parameters like energy, lens types, writing speed and polarisation on the size and shape of the capillaries, and compare the performance of different parameter sets.

  4. Semiconductor laser shearing interferometer

    International Nuclear Information System (INIS)

    Ming Hai; Li Ming; Chen Nong; Xie Jiaping

    1988-03-01

    The application of semiconductor laser on grating shearing interferometry is studied experimentally in the present paper. The method measuring the coherence of semiconductor laser beam by ion etching double frequency grating is proposed. The experimental result of lens aberration with semiconductor laser shearing interferometer is given. Talbot shearing interferometry of semiconductor laser is also described. (author). 2 refs, 9 figs

  5. Dye laser principles with applications

    CERN Document Server

    Duarte, Frank J; Liao, Peter F; Kelley, Paul

    1990-01-01

    A tutorial introduction to the field of dye lasers, Dye Laser Principles also serves as an up-to-date overview for those using dye lasers as research and industrial tools. A number of the issues discussed in this book are pertinent not only to dye lasers but also to lasers in general. Most of the chapters in the book contain problem sets that expand on the material covered in the chapter.Key Features* Dye lasers are among the most versatile and successful laser sources currently available in use Offering both pulsed and continuous-wave operation and tunable from the near ultraviole

  6. Present and future of laser welding machine; Laser yosetsuki no genjo to tenbo

    Energy Technology Data Exchange (ETDEWEB)

    Taniu, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1998-04-01

    This paper describes recent trends of laser welding machine. For CO2 laser welding machine, seam weld of large diameter weld pipes using a 25 kW-class machine, and plate weld of steel plate using a 45 kW-class machine are reported. For YAG laser welding machine, high-output 5.5 kW-class machines are commercialized. Machines with slab structure of plate-like YAG chrystal have been developed which show high-oscillation efficiency and can be applied to cutting. Machines have been developed in which YAG laser output with slab structure is transmitted through GI fiber. High-speed welding of aluminum alloys can be realized by improving the converging performance. Efficiency of YAG laser can be enhanced through the time-divided utilization by switching the beam transmission path using fiber change-over switch. In the automobile industry, CO2 laser is mainly used, and a system combining CO laser with articulate robot is realized. TIG and MIG welding is often used for welding of aluminum for railway vehicles. It is required to reduce the welding strain. In the iron and steel industry, the productivity has been improved by the laser welding. YAG laser is put into practice for nuclear reactors. 5 refs., 8 figs., 1 tab.

  7. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  8. Free electron laser

    International Nuclear Information System (INIS)

    Ortega, J.M.; Billardon, M.

    1986-01-01

    Operation principle of a laser and an oscillator are recalled together with the klystron one. In the free electron laser, electrons go through an undulator or an optical klystron. Principles of the last one are given. The two distinct ways of producing coherent radiation with an undulator and an optical klystron are presented. The first one is the use of the free electron laser, the second is to make use of the spontaneous emission generation (harmonics generation). The different current types of free electron lasers are presented (Stanford, Los Alamos, Aco at Orsay). Prospects and applications are given in conclusion [fr

  9. Solid-state laser engineering

    CERN Document Server

    Koechner, Walter

    1999-01-01

    Solid-State Laser Engineering, written from an industrial perspective, discusses in detail the characteristics, design, construction, and performance of solid-state lasers. Emphasis is placed on engineering and practical considerations; phenomenological aspects using models are preferred to abstract mathematical derivations. This new edition has extensively been updated to account for recent developments in the areas of diode-laser pumping, laser materials, and nonlinear crystals. Walter Koechner received a doctorate in Electrical Engineering from the University of Technology in Vienna, Austria, in 1965. He has published numerous papers in the fields of solid-state physics, optics, and lasers. Dr. Koechner is founder and president of Fibertek, Inc., a research firm specializing in the design, development, and production of advanced solid-state lasers, optical radars, and remote-sensing systems.

  10. Experimental comparison of laser energy losses in high-quality laser-oxygen cutting of low-carbon steel using radiation from fibre and CO2 lasers

    International Nuclear Information System (INIS)

    Golyshev, A A; Malikov, A G; Orishich, A M; Shulyat'ev, V B

    2015-01-01

    We report a comparative experimental study of laseroxygen cutting of low-carbon steel using a fibre laser with a wavelength of 1.07 μm and a CO 2 laser with a wavelength of 10.6 μm at the sheet thickness of 3 – 16 mm. For the two lasers we have measured the dependence of the cutting speed on the radiation power and determined the cutting speed at which the surface roughness is minimal. The coefficient of laser radiation absorption in the laser cutting process is measured for these lasers at different values of the cutting speed and radiation power. It is found that the minimal roughness of the cut surface is reached at the absorbed laser energy per unit volume of the removed material, equal to 11 – 13 J mm -3 ; this value is the same for the two lasers and does not depend on the sheet thickness. (laser technologies)

  11. Laser-material interactions: A study of laser energy coupling with solids

    Energy Technology Data Exchange (ETDEWEB)

    Shannon, Mark Alan [Univ. of California, Berkeley, CA (United States)

    1993-11-01

    This study of laser-light interactions with solid materials ranges from low-temperature heating to explosive, plasma-forming reactions. Contained are four works concerning laser-energy coupling: laser (i) heating and (ii) melting monitored using a mirage effect technique, (iii) the mechanical stress-power generated during high-powered laser ablation, and (iv) plasma-shielding. First, a photothermal deflection (PTD) technique is presented for monitoring heat transfer during modulated laser heating of opaque solids that have not undergone phase-change. Of main interest is the physical significance of the shape, magnitude, and phase for the temporal profile of the deflection signal. Considered are the effects that thermophysical properties, boundary conditions, and geometry of the target and optical probe-beam have on the deflection response. PTD is shown to monitor spatial and temporal changes in heat flux leaving the surface due to changes in laser energy coupling. The PTD technique is then extended to detect phase-change at the surface of a solid target. Experimental data shows the onset of melt for indium and tin targets. The conditions for which melt can be detected by PTD is analyzed in terms of geometry, incident power and pulse length, and thermophysical properties of the target and surroundings. Next, monitoring high-powered laser ablation of materials with stress-power is introduced. The motivation for considering stress-power is given, followed by a theoretical discussion of stress-power and how it is determined experimentally. Experiments are presented for the ablation of aluminum targets as a function of energy and intensity. The stress-power response is analyzed for its physical significance. Lastly, the influence of plasma-shielding during high-powered pulsed laser-material interactions is considered. Crater size, emission, and stress-power are measured to determine the role that the gas medium and laser pulse length have on plasma shielding.

  12. Laser-material interactions: A study of laser energy coupling with solids

    International Nuclear Information System (INIS)

    Shannon, M.A.; California Univ., Berkeley, CA

    1993-11-01

    This study of laser-light interactions with solid materials ranges from low-temperature heating to explosive, plasma-forming reactions. Contained are four works concerning laser-energy coupling: laser (i) heating and (ii) melting monitored using a mirage effect technique, (iii) the mechanical stress-power generated during high-powered laser ablation, and (iv) plasma-shielding. First, a photothermal deflection (PTD) technique is presented for monitoring heat transfer during modulated laser heating of opaque solids that have not undergone phase-change. Of main interest is the physical significance of the shape, magnitude, and phase for the temporal profile of the deflection signal. Considered are the effects that thermophysical properties, boundary conditions, and geometry of the target and optical probe-beam have on the deflection response. PTD is shown to monitor spatial and temporal changes in heat flux leaving the surface due to changes in laser energy coupling. The PTD technique is then extended to detect phase-change at the surface of a solid target. Experimental data shows the onset of melt for indium and tin targets. The conditions for which melt can be detected by PTD is analyzed in terms of geometry, incident power and pulse length, and thermophysical properties of the target and surroundings. Next, monitoring high-powered laser ablation of materials with stress-power is introduced. The motivation for considering stress-power is given, followed by a theoretical discussion of stress-power and how it is determined experimentally. Experiments are presented for the ablation of aluminum targets as a function of energy and intensity. The stress-power response is analyzed for its physical significance. Lastly, the influence of plasma-shielding during high-powered pulsed laser-material interactions is considered. Crater size, emission, and stress-power are measured to determine the role that the gas medium and laser pulse length have on plasma shielding

  13. Laser Dyes

    Indian Academy of Sciences (India)

    amplification or generation of coherent light waves in the UV,. VIS, and near IR region. .... ciency in most flashlamp pumped dye lasers. It is used as reference dye .... have led to superior laser dyes with increased photostabilities. For instance ...

  14. Plasma cutting or laser cutting. Plasma setsudan ka laser setsudan ka

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, A. (Tanaka Engineering Works Ltd., Saitama (Japan))

    1991-05-01

    Comparisons and discussions were made on the plasma cutting and laser cutting in sheet steel cutting, referring partly to gas cutting. Historically, the cutting has been developed from gas, plasma, and laser in that order, and currently these three methods are used mixedly. Generally, the plasma cutting is superior in cutting speed, but inferior in cut face quality, and it requires measures of dust collection. Due to high accuracy and quality in cut face, the laser cutting has been practically used for quite some time in the thin sheet industry, but medium to thick sheet cutting had a problem of unavailability of high output laser suitable for these ranges. However, the recent technologies have overcome the problem as a result of development at the authors {prime} company of a 2 kW class laser cutter capable of cutting 19 mm thick sheet. The cutter has been proven being particularly excellent in controllability. Choice of whether plasma or laser would depend upon which priority is to be taken, cost or accuracy. 15 figs., 3 tabs.

  15. Really Large Scale Computer Graphic Projection Using Lasers and Laser Substitutes

    Science.gov (United States)

    Rother, Paul

    1989-07-01

    This paper reflects on past laser projects to display vector scanned computer graphic images onto very large and irregular surfaces. Since the availability of microprocessors and high powered visible lasers, very large scale computer graphics projection have become a reality. Due to the independence from a focusing lens, lasers easily project onto distant and irregular surfaces and have been used for amusement parks, theatrical performances, concert performances, industrial trade shows and dance clubs. Lasers have been used to project onto mountains, buildings, 360° globes, clouds of smoke and water. These methods have proven successful in installations at: Epcot Theme Park in Florida; Stone Mountain Park in Georgia; 1984 Olympics in Los Angeles; hundreds of Corporate trade shows and thousands of musical performances. Using new ColorRayTM technology, the use of costly and fragile lasers is no longer necessary. Utilizing fiber optic technology, the functionality of lasers can be duplicated for new and exciting projection possibilities. The use of ColorRayTM technology has enjoyed worldwide recognition in conjunction with Pink Floyd and George Michaels' world wide tours.

  16. Solid-State Random Lasers

    CERN Document Server

    Noginov, Mikhail A

    2005-01-01

    Random lasers are the simplest sources of stimulated emission without cavity, with the feedback provided by scattering in a gain medium. First proposed in the late 60’s, random lasers have grown to a large research field. This book reviews the history and the state of the art of random lasers, provides an outline of the basic models describing their behavior, and describes the recent advances in the field. The major focus of the book is on solid-state random lasers. However, it also briefly describes random lasers based on liquid dyes with scatterers. The chapters of the book are almost independent of each other. So, the scientists or engineers interested in any particular aspect of random lasers can read directly the relevant section. Researchers entering the field of random lasers will find in the book an overview of the field of study. Scientists working in the field can use the book as a reference source.

  17. Alternate laser fusion drivers

    International Nuclear Information System (INIS)

    Pleasance, L.D.

    1979-11-01

    One objective of research on inertial confinement fusion is the development of a power generating system based on this concept. Realization of this goal will depend on the availability of a suitable laser or other system to drive the power plant. The primary laser systems used for laser fusion research, Nd 3+ : Glass and CO 2 , have characteristics which may preclude their use for this application. Glass lasers are presently perceived to be incapable of sufficiently high average power operation and the CO 2 laser may be limited by and issues associated with target coupling. These general perceptions have encouraged a search for alternatives to the present systems. The search for new lasers has been directed generally towards shorter wavelengths; most of the new lasers discovered in the past few years have been in the visible and ultraviolet region of the spectrum. Virtually all of them have been advocated as the most promising candidate for a fusion driver at one time or another

  18. Laser-driven hydrothermal process studied with excimer laser pulses

    Science.gov (United States)

    Mariella, Raymond; Rubenchik, Alexander; Fong, Erika; Norton, Mary; Hollingsworth, William; Clarkson, James; Johnsen, Howard; Osborn, David L.

    2017-08-01

    Previously, we discovered [Mariella et al., J. Appl. Phys. 114, 014904 (2013)] that modest-fluence/modest-intensity 351-nm laser pulses, with insufficient fluence/intensity to ablate rock, mineral, or concrete samples via surface vaporization, still removed the surface material from water-submerged target samples with confinement of the removed material, and then dispersed at least some of the removed material into the water as a long-lived suspension of nanoparticles. We called this new process, which appears to include the generation of larger colorless particles, "laser-driven hydrothermal processing" (LDHP) [Mariella et al., J. Appl. Phys. 114, 014904 (2013)]. We, now, report that we have studied this process using 248-nm and 193-nm laser light on submerged concrete, quartzite, and obsidian, and, even though light at these wavelengths is more strongly absorbed than at 351 nm, we found that the overall efficiency of LDHP, in terms of the mass of the target removed per Joule of laser-pulse energy, is lower with 248-nm and 193-nm laser pulses than with 351-nm laser pulses. Given that stronger absorption creates higher peak surface temperatures for comparable laser fluence and intensity, it was surprising to observe reduced efficiencies for material removal. We also measured the nascent particle-size distributions that LDHP creates in the submerging water and found that they do not display the long tail towards larger particle sizes that we had observed when there had been a multi-week delay between experiments and the date of measuring the size distributions. This is consistent with transient dissolution of the solid surface, followed by diffusion-limited kinetics of nucleation and growth of particles from the resulting thin layer of supersaturated solution at the sample surface.

  19. Degenerate band edge laser

    Science.gov (United States)

    Veysi, Mehdi; Othman, Mohamed A. K.; Figotin, Alexander; Capolino, Filippo

    2018-05-01

    We propose a class of lasers based on a fourth-order exceptional point of degeneracy (EPD) referred to as the degenerate band edge (DBE). EPDs have been found in parity-time-symmetric photonic structures that require loss and/or gain; here we show that the DBE is a different kind of EPD since it occurs in periodic structures that are lossless and gainless. Because of this property, a small level of gain is sufficient to induce single-frequency lasing based on a synchronous operation of four degenerate Floquet-Bloch eigenwaves. This lasing scheme constitutes a light-matter interaction mechanism that leads also to a unique scaling law of the laser threshold with the inverse of the fifth power of the laser-cavity length. The DBE laser has the lowest lasing threshold in comparison to a regular band edge laser and to a conventional laser in cavities with the same loaded quality (Q ) factor and length. In particular, even without mirror reflectors the DBE laser exhibits a lasing threshold which is an order of magnitude lower than that of a uniform cavity laser of the same length and with very high mirror reflectivity. Importantly, this novel DBE lasing regime enforces mode selectivity and coherent single-frequency operation even for pumping rates well beyond the lasing threshold, in contrast to the multifrequency nature of conventional uniform cavity lasers.

  20. Precise femtosecond laser ablation of dental hard tissue: preliminary investigation on adequate laser parameters

    International Nuclear Information System (INIS)

    Hikov, Todor; Pecheva, Emilia; Petrov, Todor; Montgomery, Paul; Antoni, Frederic; Leong-Hoi, Audrey

    2017-01-01

    This work aims at evaluating the possibility of introducing state-of-the-art commercial femtosecond laser system in restorative dentistry by maintaining well-known benefits of lasers for caries removal, but also in overcoming disadvantages such as thermal damage of irradiated substrate. Femtosecond ablation of dental hard tissue is investigated by changing the irradiation parameters (pulsed laser energy, scanning speed and pulse repetition rate), assessed for enamel and dentin. The femtosecond laser system used in this work may be suitable for cavity preparation in dentin and enamel, due to the expected effective ablation and low temperature increase when using ultra short laser pulses. If adequate laser parameters are selected, this system seems to be promising for promoting a laser-assisted, minimally invasive approach in restorative dentistry. (paper)

  1. Semiconductor lasers stability, instability and chaos

    CERN Document Server

    Ohtsubo, Junji

    2017-01-01

    This book describes the fascinating recent advances made concerning the chaos, stability and instability of semiconductor lasers, and discusses their applications and future prospects in detail. It emphasizes the dynamics in semiconductor lasers by optical and electronic feedback, optical injection, and injection current modulation. Applications of semiconductor laser chaos, control and noise, and semiconductor lasers are also demonstrated. Semiconductor lasers with new structures, such as vertical-cavity surface-emitting lasers and broad-area semiconductor lasers, are intriguing and promising devices. Current topics include fast physical number generation using chaotic semiconductor lasers for secure communication, development of chaos, quantum-dot semiconductor lasers and quantum-cascade semiconductor lasers, and vertical-cavity surface-emitting lasers. This fourth edition has been significantly expanded to reflect the latest developments. The fundamental theory of laser chaos and the chaotic dynamics in se...

  2. uv dye lasers

    International Nuclear Information System (INIS)

    Abakumov, G.A.; Fadeev, V.V.; Khokhlov, R.V.; Simonov, A.P.

    1975-01-01

    The most important property of visible dye lasers, that is, continuous wavelength tuning, stimulated the search for dyes capable to lase in uv. They were found in 1968. Now the need for tunable uv lasers for applications in spectroscopy, photochemistry, isotope separation, remote air and sea probing, etc. is clearly seen. A review of some recent advances in uv dye lasers is reviewed

  3. Laser fusion: an overview

    International Nuclear Information System (INIS)

    Boyer, K.

    1975-01-01

    The laser fusion concept is described along with developments in neodymium and carbon dioxide lasers. Fuel design and fabrication are reviewed. Some spin-offs of the laser fusion program are discussed. (U.S.)

  4. High energy HF pulsed lasers

    International Nuclear Information System (INIS)

    Patterson, E.L.; Gerber, R.A.

    1976-01-01

    Recent experiments show that pulsed HF lasers are capable of producing high energy with good efficiency. Preliminary experiments show that the laser radiation from the high-gain medium can be controlled with a low-power probe laser beam or with low-level feedback. These results indicate that the HF laser may have potential for second-generation laser fusion experiments

  5. Optical pumping of Rb by Ti:Sa laser and high-power laser diode

    Czech Academy of Sciences Publication Activity Database

    Buchta, Zdeněk; Rychnovský, Jan; Lazar, Josef

    2006-01-01

    Roč. 8, č. 1 (2006), s. 350-354 ISSN 1454-4164 R&D Projects: GA AV ČR IAA1065303; GA ČR GA102/04/2109 Institutional research plan: CEZ:AV0Z20650511 Keywords : optical pumping * Ti:Sa laser * laser diode * emission linewidth * spectroscopy * laser frequency stabilization Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.106, year: 2006

  6. The suppression of radiation reaction and laser field depletion in laser-electron beam interaction

    Science.gov (United States)

    Ong, J. F.; Moritaka, T.; Takabe, H.

    2018-03-01

    The effects of radiation reaction (RR) have been studied extensively by using the interaction of ultraintense lasers with a counter-propagating relativistic electron. At the laser intensity at the order of 1023 W/cm2, the effects of RR are significant in a few laser periods for a relativistic electron. However, a laser at such intensity is tightly focused and the laser energy is usually assumed to be fixed. Then, the signal of RR and energy conservation cannot be guaranteed. To assess the effects of RR in a tightly focused laser pulse and the evolution of the laser energy, we simulated this interaction with a beam of 109 electrons by means of a Particle-In-Cell method. We observe that the effects of RR are suppressed due to the ponderomotive force and accompanied by a non-negligible amount of laser field energy reduction. This is because the ponderomotive force prevents the electrons from approaching the center of the laser pulse and leads to an interaction at the weaker field region. At the same time, the laser energy is absorbed through ponderomotive acceleration. Thus, the kinetic energy of the electron beam has to be carefully selected such that the effects of RR become obvious.

  7. Integrated laser-target interaction experiments on the RAL petawatt laser

    International Nuclear Information System (INIS)

    Patel, P K; Key, M H; Mackinnon, A J

    2005-01-01

    We review a recent experimental campaign to study the interaction physics of petawatt laser pulses incident at relativistic intensities on solid targets. The campaign was performed on the 500 J sub-picosecond petawatt laser at the Rutherford Appleton Laboratory. An extensive suite of optical, x-ray, and particle diagnostics was employed to characterise the processes of laser absorption, electron generation and transport, thermal and K-alpha x-ray generation, and proton acceleration

  8. Vacuum ultraviolet Ar2*laser pumped by a high-intensity laser

    International Nuclear Information System (INIS)

    Kubodera, Shoichi; Kaku, Masanori; Higashiguchi, Takeshi

    2004-01-01

    We observed a small-signal gain of Ar 2 * emission at 126 nm by use of an Ar-filled hollow fiber to guide the ultrashort-pulse high-intensity laser propagation. The small signal gain coefficient was measured to be 0.05 cm -1 at 126 nm. Kinetic analysis revealed that the electrons produced by the high-intensity laser through an optical-field ionization process initiated the Ar 2 * production process. This laser scheme could be combined with high harmonic radiation of the pump laser in the vacuum ultraviolet (VUV), leading to the production of amplified ultrashort VUV pulses. (author)

  9. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Directory of Open Access Journals (Sweden)

    Torbeck R

    2016-05-01

    Full Text Available Richard Torbeck,1 Richard Bankowski,2 Sarah Henize,3 Nazanin Saedi,11Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 2Cynosure, Inc, Westford, MA, 3Huron Consulting Group, Chicago, IL, USABackground and objectives: The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm. Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal.Study design and methods: A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal".Results: A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow. Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change.Conclusion: Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments.Keywords: tattoo, removal, laser, picosecond 

  10. Femtosecond Fiber Lasers

    Science.gov (United States)

    Bock, Katherine J.

    This thesis focuses on research I have done on ytterbium-doped femtosecond fiber lasers. These lasers operate in the near infrared region, lasing at 1030 nm. This wavelength is particularly important in biomedical applications, which includes but is not limited to confocal microscopy and ablation for surgical incisions. Furthermore, fiber lasers are advantageous compared to solid state lasers in terms of their cost, form factor, and ease of use. Solid state lasers still dominate the market due to their comparatively high energy pulses. High energy pulse generation in fiber lasers is hindered by either optical wave breaking or by multipulsing. One of the main challenges for fiber lasers is to overcome these limitations to achieve high energy pulses. The motivation for the work done in this thesis is increasing the output pulse peak power and energy. The main idea of the work is that decreasing the nonlinearity that acts on the pulse inside the cavity will prevent optical wave breaking, and thus will generate higher energy pulses. By increasing the output energy, ytterbium-doped femtosecond fiber lasers can be competitive with solid state lasers which are used commonly in research. Although fiber lasers tend to lack the wavelength tuning ability of solid state lasers, many biomedical applications take advantage of the 1030 microm central wavelength of ytterbium-doped fiber lasers, so the major limiting factor of fiber lasers in this field is simply the output power. By increasing the output energy without resorting to external amplification, the cavity is optimized and cost can remain low and economical. During verification of the main idea, the cavity was examined for possible back-reflections and for components with narrow spectral bandwidths which may have contributed to the presence of multipulsing. Distinct cases of multipulsing, bound pulse and harmonic mode-locking, were observed and recorded as they may be of more interest in the future. The third

  11. Single frequency semiconductor lasers

    CERN Document Server

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui

    2017-01-01

    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  12. Strong field laser physics

    CERN Document Server

    2008-01-01

    Since the invention of the laser in the 1960s, people have strived to reach higher intensities and shorter pulse durations. High intensities and ultrashort pulse durations are intimately related. Recent developments have shown that high intensity lasers also open the way to realize pulses with the shortest durations to date, giving birth to the field of attosecond science (1 asec = 10-18s). This book is about high-intensity lasers and their applications. The goal is to give an up to date introduction to the technology behind these laser systems and to the broad range of intense laser applications. These applications include AMO (atomic molecular and optical) physics, x-ray science, attosecond science, plasma physics and particle acceleration, condensed matter science and laser micromachining, and finally even high-energy physics.

  13. Direct diode lasers with comparable beam quality to fiber, CO2, and solid state lasers

    Science.gov (United States)

    Huang, Robin K.; Chann, Bien; Burgess, James; Kaiman, Michael; Overman, Robert; Glenn, John D.; Tayebati, Parviz

    2012-03-01

    TeraDiode has produced kW-class ultra-high brightness fiber-coupled direct diode lasers. A fiber-coupled direct diode laser with a power level of 2,040 W from a 50 μm core diameter, 0.15 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. This was achieved with a novel beam combining and shaping technique using COTS diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.75 mm-mrad and is the lowest BPP kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 2-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers.

  14. Pulsed CH3OH terahertz laser radiation pumped by 9P(36) CO2 lasers

    International Nuclear Information System (INIS)

    Jiu Zhixian; Zuo Duluo; Miao Liang; Cheng Zuhai

    2011-01-01

    An efficient pulsed CH 3 OH terahertz (THz) laser pumped by a TEA CO 2 laser was investigated experimentally. A simple terahertz cavity and a TEA CO 2 laser for the optically pumped THz radiation were studied experimentally. To improve THz laser energy and photon conversion efficiency, two different TEA CO 2 lasers were developed to pump CH 3 OH. When CH 3 OH was pumped by the 9P(36) line with different powers of the CO 2 laser, the generation of terahertz radiation with energy as high as 0.307mJ and 23.75mJ were obtained, respectively. The corresponding photon conversion efficiencies were 0.29% and 2.4%. The photon conversion efficiency increases by a factor of about 8. Meanwhile, higher peak power of pump laser effectively improves the photon conversion efficiency. And the optimum THz laser pressure increases with narrower pulse width of pump laser because of increasing absorptive gases molecules of CH 3 OH with higher peak power of pump laser.

  15. Lasers '90: Proceedings of the 13th International Conference on Lasers and Applications, San Diego, CA, Dec. 10-14, 1990

    International Nuclear Information System (INIS)

    Harris, D.G.; Herbelin, J.

    1991-01-01

    The general topics considered are: x-ray lasers; FELs; solid state lasers; techniques and phenomena of ultrafast lasers; optical filters and free space laser communications; discharge lasers; tunable lasers; applications of lasers in medicine and surgery; lasers in materials processing; high power lasers; dynamics gratings, wave mixing, and holography; up-conversion lasers; lidar and laser radar; laser resonators; excimer lasers; laser propagation; nonlinear and quantum optics; blue-green technology; imaging; laser spectroscopy; chemical lasers; dye lasers; and lasers in chemistry

  16. Laser Wakefield Acceleration Driven by a CO2 Laser (STELLA-LW) - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Wayne D

    2008-06-27

    The original goals of the Staged Electron Laser Acceleration – Laser Wakefield (STELLA-LW) program were to investigate two new methods for laser wakefield acceleration (LWFA). In pseudo-resonant LWFA (PR-LWFA), a laser pulse experiences nonlinear pulse steepening while traveling through the plasma. This steepening allows the laser pulse to generate wakefields even though the laser pulse length is too long for resonant LWFA to occur. For the conditions of this program, PR-LWFA requires a minimum laser peak power of 3 TW and a low plasma density (10^16 cm^-3). Seeded self-modulated LWFA (seeded SM-LWFA) combines LWFA with plasma wakefield acceleration (PWFA). An ultrashort (~100 fs) electron beam bunch acts as a seed in a plasma to form a wakefield via PWFA. This wakefield is subsequently amplified by the laser pulse through a self-modulated LWFA process. At least 1 TW laser power and, for a ~100-fs bunch, a plasma density ~10^17 cm^-3 are required. STELLA-LW was located on Beamline #1 at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). The ATF TW CO2 laser served as the driving laser beam for both methods. For PR-LWFA, a single bunch was to probe the wakefield produced by the laser beam. For seeded SM-LWFA, the ATF linac would produce two bunches, where the first would be the seed and the second would be the witness. A chicane would compress the first bunch to enable it to generate wakefields via PWFA. The plasma source was a short-length, gas-filled capillary discharge with the laser beam tightly focused in the center of the capillary, i.e., no laser guiding was used, in order to obtain the needed laser intensity. During the course of the program, several major changes had to be made. First, the ATF could not complete the upgrade of the CO2 laser to the 3 TW peak power needed for the PR-LWFA experiment. Therefore, the PR-LWFA experiment had to be abandoned leaving only the seeded SM-LWFA experiment. Second, the ATF discovered that the

  17. Laser Doppler flowmetry evaluation of gingival recovery response after laser treatment

    Science.gov (United States)

    Todea, Carmen; Cânjǎu, Silvana; Dodenciu, Dorin; Miron, Mariana I.; Tudor, Anca; Bǎlǎbuc, Cosmin

    2013-06-01

    This study was performed in order to evaluate in vivo the applicability of Laser Doppler Flowmetry (LDF) in recording the gingival blood flow and to assess the changes of gingival blood flow following gingival reshaping performed with Er:YAG and 980 nm diode lasers. The LDF evaluation was performed on 20 anterior teeth, which underwent reshaping of gingiva, corresponding to 5 female patients (4 anterior teeth/patient), aged between 20 and 35. One part of the mouth was treated with Er:YAG laser (LP, VLP modes, 140 - 250 mJ, 10 - 20 Hz, using cylindrical sapphire tips) and other part with 980 nm diode laser (CW, 4 W, contact mode and saline solution cooling). The gingival blood flow was monitored using a MoorLab laser Doppler equipment (Moor Instruments Ltd., Axminster, UK) with a straight optical probe, MP3b, 10 mm. The data were processed using statistical analysis software SPSS v16.0.1. The investigation showed an evident decrease in perfusion for both areas in comparison with the baseline values 24 hours after treatment. The microvascular blood flow increased significantly after 7 days in both areas but mostly in diode area (pdiode area remained at a high level after 14 days. Both lasers proved efficiency in the surgical treatment of gingival tissue. Moreover, Laser Doppler Flowmetry is adequate for recording changes in gingival blood flow following periodontal surgery.

  18. Pulsed laser facilities operating from UV to IR at the Gas Laser Lab of the Lebedev Institute

    Science.gov (United States)

    Ionin, Andrei; Kholin, Igor; Vasil'Ev, Boris; Zvorykin, Vladimir

    2003-05-01

    Pulsed laser facilities developed at the Gas Lasers Lab of the Lebedev Physics Institute and their applications for different laser-matter interactions are discussed. The lasers operating from UV to mid-IR spectral region are as follows: e-beam pumped KrF laser (λ= 0.248 μm) with output energy 100 J; e-beam sustained discharge CO2(10.6 μm) and fundamental band CO (5-6 μm) lasers with output energy up to ~1 kJ; overtone CO laser (2.5-4.2 μm) with output energy ~ 50 J and N2O laser (10.9 μm) with output energy of 100 J; optically pumped NH3 laser (11-14 μm). Special attention is paid to an e-beam sustained discharge Ar-Xe laser (1.73 μm ~ 100 J) as a potential candidate for a laser-propulsion facility. The high energy laser facilities are used for interaction of laser radiation with polymer materials, metals, graphite, rocks, etc.

  19. Femtosecond Laser Filamentation

    CERN Document Server

    Chin, See Leang

    2010-01-01

    Femtosecond Laser Filamentation gives a comprehensive review of the physics of propagation of intense femtosecond laser pulses in optical media (principally air) and the applications and challenges of this new technique. This book presents the modern understanding of the physics of femtosecond laser pulse propagation, including unusual new effects such as the self-transformation of the pulse into a white light laser pulse, intensity clamping, the physics of multiple filamentation and competition, and how filaments’ ability to melt glass leads to wave guide writing. The potential applications of laser filamentation in atmospheric sensing and the generation of other electromagnetic pulses from the UV to the radio frequency are treated, together with possible future challenges in the excitation of super-excited states of molecules. Exciting new phenomena such as filament induced ultrafast birefringence and the excitation of molecular rotational wave packets and their multiple revivals in air (gases) will also ...

  20. Applications of lasers and electro-optics

    International Nuclear Information System (INIS)

    Tan, B.C.; Low, K.S.; Chen, Y.H.; Harith bin Ahmad; Tou, T.Y.

    1994-01-01

    Supported by the IRPA Programme on Laser Technology and Applications, many types of lasers have been designed, constructed and applied in various areas of science, medicine and industries. Amongst these lasers constructed were high power carbon dioxide lasers, rare gas halide excimer lasers, solid state Neodymium-YAG lasers, nitrogen lasers, flashlamp pumped dye lasers and nitrogen and excimer laser pumped dye lasers. These lasers and the associated electro-optics system, some with computer controlled, are designed and developed for the following areas of applications: 1. Industrial applications of high power carbon dioxide lasers for making of i.c. components and other materials processing purposes. Prototype operational systems have been developed. 2. Medical applications of lasers for cancer treatment using the technique of photodynamic therapy. A new and more effective treatment protocol has been proposed. 3. Agricultural applications of lasers in palm oil and palm fruit-fluorescence diagnostic studies. Fruit ripeness signature has been developed and palm oil oxidation level were investigated. 4. Development of atmospheric pollution monitoring systems using laser lidar techniques. Laboratory scale systems were developed. 5. Other applications of lasers including laser holographic and interferometric methods for the non destructive testing of materials. The activities of the group (from 1988-1990) have resulted in the submission of a patent for a laser device, publication of many research paper sin local and overseas journals and conference proceedings, completion of 1 Ph.D. dissertation and 6 M. Phil theses. Currently (1991), a total of 3 Ph.D., 6 M. Phil research programmes are involved in this research and development programme

  1. FROM THE HISTORY OF LASER CREATION

    Directory of Open Access Journals (Sweden)

    I.M. Belousova

    2014-03-01

    Full Text Available The paper briefly describes the history of formation of a new science direction - quantum electronics, associated with the discovery of masers and lasers by scientists from the USA (Ch. Townes and the USSR (N.G. Basov and A. M. Prokhorov. The world's first ruby laser designed by T. Maiman is described. Some historical events devoted to creation and research of lasers are given in which the author of the paper as well as research workers from Vavilov State Optical Institute, ITMO University and LOMO have taken direct part in the development of solid-state and gas lasers (helium-neon, photodissociation, CO2-lasers and laser optical systems. Contribution of researchers from Vavilov State Optical Institute, LOMO and ITMO University to large-scale programs on development of lasers for laser nuclear fusion, laser weapons and “Phobos” program is shown. The paper deals in brief with new issues of development and application of lasers, mainly, within the project of laser orbital space station of the future, for the conversion of solar energy into laser radiation. Description of idea of solar energy transformation by fullerene-oxygen laser is presented. The patent for it has been taken out by Vavilov State Optical Institute. Developed fullerene-oxygen-iodine laser and laser structure models for industrial applications and solar energy conversion into laser radiation are described. Parameters for hypothetical laser-optical system of the future space station are given.

  2. Towards shorter wavelength x-ray lasers using a high power, short pulse pump laser

    International Nuclear Information System (INIS)

    Tighe, W.; Krushelnick, K.; Valeo, E.; Suckewer, S.

    1991-05-01

    A near-terawatt, KrF* laser system, focussable to power densities >10 18 W/cm 2 has been constructed for use as a pump laser in various schemes aimed at the development of x-ray lasing below 5nm. The laser system along with output characteristics such as the pulse duration, the focal spot size, and the percentage of amplified spontaneous emission (ASE) emitted along with the laser pulse will be presented. Schemes intended to lead to shorter wavelength x-ray emission will be described. The resultant requirements on the pump laser characteristics and the target design will be outlined. Results from recent solid target experiments and two-laser experiments, showing the interaction of a high-power, short pulse laser with a preformed plasma, will be presented. 13 refs., 5 figs

  3. Advancement of High Power Quasi-CW Laser Diode Arrays For Space-based Laser Instruments

    Science.gov (United States)

    Amzajerdian, Farzin; Meadows, Byron L.; Baker, nathaniel R.; Baggott, Renee S.; Singh, Upendra N.; Kavaya, Michael J.

    2004-01-01

    Space-based laser and lidar instruments play an important role in NASA s plans for meeting its objectives in both Earth Science and Space Exploration areas. Almost all the lidar instrument concepts being considered by NASA scientist utilize moderate to high power diode-pumped solid state lasers as their transmitter source. Perhaps the most critical component of any solid state laser system is its pump laser diode array which essentially dictates instrument efficiency, reliability and lifetime. For this reason, premature failures and rapid degradation of high power laser diode arrays that have been experienced by laser system designers are of major concern to NASA. This work addresses these reliability and lifetime issues by attempting to eliminate the causes of failures and developing methods for screening laser diode arrays and qualifying them for operation in space.

  4. Laser development for laser fusion applications research. Progress report, October 1977--March 1978

    International Nuclear Information System (INIS)

    1978-06-01

    Research progress is reported on three laser programs being developed for the commercialization of laser-fusion energy. The lasers include iodine, hydrogen fluoride and Group VI atoms (e.g., O, S, Se, Te)

  5. Resonance ionization spectroscopy using ultraviolet laser

    CERN Document Server

    Han, J M; Ko, D K; Park, H M; Rhee, Y J

    2002-01-01

    In this study, Ti:sapphire laser which is pumped by the enhanced Nd:YAG laser using laser diode, was designed and manufactured. The AO Q-switched CW Nd:YAG laser was converted into a high repetition plus-type laser using the AO Q-switch, and two heads were installed inside the cavity in order to improve the laser beam quality. The Nd:YAG laser enhancement was completed by optimization using a simulation for the cavity length, structure and thermal lens effect that greatly effected the laser beam output and quality. As the result of the enhancement, a 30W laser at 532nm and at 5k-Hz was successfully made. Also, the Ti:sapphire laser that will be used for atomic spectroscopy which is pumped by the Nd:YAG laser, was completely designed. As a basic experiment for laser oscillation. We measured the tunability of the laser, and it turned out that the wave tunability range was 730 850 nm. A self-seeding type tunable laser using grating for narrow line width, is planned to be designed due to the fact that the Ti:sapp...

  6. Progress in high-energy laser technology

    International Nuclear Information System (INIS)

    Miyanaga, Noriaki; Kitagawa, Yoneyoshi; Nakatsuka, Masahiro; Kanabe, Tadashi; Okuda, Isao

    2005-01-01

    The technological development of high-energy lasers is one of the key issues in laser fusion research. This paper reviews several technologies on the Nd:glass laser and KrF excimer laser that are being used in the current laser fusion experiments and related plasma experiments. Based on the GEKKO laser technology, a new high-energy Nd: glass laser system, which can deliver energy from 10 kJ (boad-band operation) to 20 kJ (narrow-band operation), is under construction. The key topics in KrF laser development are improved efficiency and repetitive operation, which aim at the development of a laser driven for fusion reactor. Ultra-intense-laser technology is also very important for fast ignition research. The key technology for obtaining the petawatt output with high beam quality is reviewed. Regarding the uniform laser irradiation required for high-density compression, the beam-smoothing methods on the GEKKO XII laser are reviewed. Finally, we discuss the present status of MJ-class lasers throughout the world, and summarize by presenting the feasibility of various applications of the high-energy lasers to a wide range of scientific and technological fields. (author)

  7. Free-electron laser driven by the LBNL laser-plasma accelerator

    International Nuclear Information System (INIS)

    Schroeder, C.B.; Fawley, W.M.; Gruner, F.; Bakeman, M.; Nakamura, K.; Robinson, K.E.; Toth, Cs.; Esarey, E.; Leemans, W.P.

    2008-01-01

    A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (∼10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10 13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

  8. Laser apparatus for surgery and force therapy based on high-power semiconductor and fibre lasers

    International Nuclear Information System (INIS)

    Minaev, V P

    2005-01-01

    High-power semiconductor lasers and diode-pumped lasers are considered whose development qualitatively improved the characteristics of laser apparatus for surgery and force therapy, extended the scope of their applications in clinical practice, and enhanced the efficiency of medical treatment based on the use of these lasers. The characteristics of domestic apparatus are presented and their properties related to the laser emission wavelength used in them are discussed. Examples of modern medical technologies based on these lasers are considered. (invited paper)

  9. Laser acceleration

    Science.gov (United States)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  10. Laser acceleration

    International Nuclear Information System (INIS)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-01-01

    The fundamental idea of LaserWakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wake fields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ∼ c and ultra fastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nano materials is also emerging.

  11. Cost analysis of lasers for a laser isotope separation system. Final report

    International Nuclear Information System (INIS)

    Mail, R.A.; Markovich, F.J.; Carr, R.H.

    1977-01-01

    To be of practical significance, laser isotope separation (LIS) for separation of 235 U from 238 U must exhibit attributes which make it preferable to expansion of the present facilities. Clearly the most attractive such attribute is the prospect of significant cost reductions, which preliminary studies at LLL suggest will amount to a factor of three and perhaps as much as ten. From these preliminary studies, it appears that the lasers themselves account for a very substantial portion of the capital cost of a LIS system, and a significant portion of the equipment replacement costs. Since the laser costs are so pivotal to the system cost, and the system cost is so pivotal to the choice of separation techniques, it is clear that a more detailed investigation of laser costs is required. Results are presented of a study performed by General Research Corporation (GRC) to assess the cost of lasers in a production laser isotope separation (LIS) plant

  12. Process observation in fiber laser-based selective laser melting

    Science.gov (United States)

    Thombansen, Ulrich; Gatej, Alexander; Pereira, Milton

    2015-01-01

    The process observation in selective laser melting (SLM) focuses on observing the interaction point where the powder is processed. To provide process relevant information, signals have to be acquired that are resolved in both time and space. Especially in high-power SLM, where more than 1 kW of laser power is used, processing speeds of several meters per second are required for a high-quality processing results. Therefore, an implementation of a suitable process observation system has to acquire a large amount of spatially resolved data at low sampling speeds or it has to restrict the acquisition to a predefined area at a high sampling speed. In any case, it is vitally important to synchronously record the laser beam position and the acquired signal. This is a prerequisite that allows the recorded data become information. Today, most SLM systems employ f-theta lenses to focus the processing laser beam onto the powder bed. This report describes the drawbacks that result for process observation and suggests a variable retro-focus system which solves these issues. The beam quality of fiber lasers delivers the processing laser beam to the powder bed at relevant focus diameters, which is a key prerequisite for this solution to be viable. The optical train we present here couples the processing laser beam and the process observation coaxially, ensuring consistent alignment of interaction zone and observed area. With respect to signal processing, we have developed a solution that synchronously acquires signals from a pyrometer and the position of the laser beam by sampling the data with a field programmable gate array. The relevance of the acquired signals has been validated by the scanning of a sample filament. Experiments with grooved samples show a correlation between different powder thicknesses and the acquired signals at relevant processing parameters. This basic work takes a first step toward self-optimization of the manufacturing process in SLM. It enables the

  13. Modematic: a fast laser beam analyzing system for high power CO2-laser beams

    Science.gov (United States)

    Olsen, Flemming O.; Ulrich, Dan

    2003-03-01

    The performance of an industrial laser is very much depending upon the characteristics of the laser beam. The ISO standards 11146 and 11154 describing test methods for laser beam parameters have been approved. To implement these methods in industry is difficult and especially for the infrared laser sources, such as the CO2-laser, the availabl analyzing systems are slow, difficult to apply and having limited reliability due to the nature of the detection methods. In an EUREKA-project the goal was defined to develop a laser beam analyzing system dedicated to high power CO2-lasers, which could fulfill the demands for an entire analyzing system, automating the time consuming pre-alignment and beam conditioning work required before a beam mode analyses, automating the analyzing sequences and data analysis required to determine the laser beam caustics and last but not least to deliver reliable close to real time data to the operator. The results of this project work will be described in this paper. The research project has led to the development of the Modematic laser beam analyzer, which is ready for the market.

  14. Influence of laser frequency noise on scanning Fabry-Perot interferometer based laser Doppler velocimetry

    DEFF Research Database (Denmark)

    Rodrigo, Peter John; Pedersen, Christian

    2014-01-01

    n this work, we study the performance of a scanning Fabry-Perot interferometer based laser Doppler velocimeter (sFPILDV) and compare two candidate 1.5 um single-frequency laser sources for the system – a fiber laser (FL) and a semiconductor laser (SL). We describe a straightforward calibration...... procedure for the sFPI-LDV and investigate the effect of different degrees of laser frequency noise between the FL and the SL on the velocimeter’s performance...

  15. A dye center laser pumped by emission from copper vapor and dye lasers

    Energy Technology Data Exchange (ETDEWEB)

    Loktyushin, A A; Chernyshev, A I; Soldatov, A N; Sukhanov, V B; Troitskiy, V O

    1983-01-01

    LiF:F2+ lasing is reported for the case of pumping by total emission with frequencies of 570.6 and 578.2 nanometers or by a single yellow copper vapor laser line and emission from an oxazene-17 dye laser excited by emission from a Cu laser. Lasing with a mean power level of 23 milliwatts with a maximum at 911 nanometers is obtained. The maximum efficiency was 3.4 percent with pumping of the dye centers by emission from the yellow Cu laser line. The lasing characteristics of the laser for all the types of pumping used are given.

  16. Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1987-04-01

    A color laser microscope utilizing a new color laser imaging system has been developed for the visual inspection of semiconductors. The light source, produced by three lasers (Red; He-Ne, Green; Ar, Blue; He-Cd), is deflected horizontally by an AOD (Acoustic Optical Deflector) and vertically by a vibration mirror. The laser beam is focused in a small spot which is scanned over the sample at high speed. The light reflected back from the sample is reformed to contain linear information by returning to the original vibration mirror. The linear light is guided to the CCD image sensor where it is converted into a video signal. Individual CCD image sensors are used for each of the three R, G, or B color image signals. The confocal optical system with its laser light source yields a color TV monitor image with no flaring and a much sharper resolution than that of the conventional optical microscope. The AOD makes possible a high speed laser scan and a NTSC or PAL TV video signal is produced in real time without any video memory. Since the light source is composed of R, G, and B laser beams, color separation superior to that of white light illumination is achieved. Because of the photometric linearity of the image detector, the R, G, and B outputs of the system are most suitably used for hue analysis. The CCD linear image sensors in the optical system produce no geometrical distortion, and good color registration is available principally. The output signal can be used for high accuracy line width measuring. The many features of the color laser microscope make it ideally suited for the visual inspection of semiconductor processing. A number of these systems have already been installed in such a capacity. The Color Laser Microscope can also be a very useful tool for the fields of material engineering and biotechnology.

  17. Tritium-doping enhancement of polystyrene by ultraviolet laser and hydrogen plasma irradiation for laser fusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Iwasa, Yuki, E-mail: iwasa-y@ile.osaka-u.ac.jp [Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Yamanoi, Kohei; Iwano, Keisuke; Empizo, Melvin John F.; Arikawa, Yasunobu; Fujioka, Shinsuke; Sarukura, Nobuhiko; Shiraga, Hiroyuki; Takagi, Masaru; Norimatsu, Takayoshi; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Noborio, Kazuyuki; Hara, Masanori; Matsuyama, Masao [Hydrogen Isotope Research Center, Organization for Promotion of Research, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)

    2016-11-15

    Highlights: • Tritium-doped polystyrene films are fabricated by the Wilzbach method with UV laser and hydrogen plasma irradiation. • The 266-nm laser-irradiated, 355-nm laser-irradiated, and hydrogen plasma-irradiated polystyrene films exhibit higher PSL intensities and specific radioactivities than the non-irradiated sample. • Tritium doping by UV laser irradiation can be largely affected by the laser wavelength because of polystyrene’s absorption. • Hydrogen plasma irradiation results to a more uniform doping concentration even at low partial pressure and short irradiation time. • UV laser and plasma irradiations can be utilized to fabricate tritium-doped polystyrene shell targets for future laser fusion experiments. - Abstract: We investigate the tritium-doping enhancement of polystyrene by ultraviolet (UV) laser and hydrogen plasma irradiation. Tritium-doped polystyrene films are fabricated by the Wilzbach method with UV laser and hydrogen plasma. The 266-nm laser-irradiated, 355-nm laser-irradiated, and hydrogen plasma-irradiated polystyrene films exhibit higher PSL intensities and specific radioactivities than the non-irradiated sample. Tritium doping by UV laser irradiation can be largely affected by the laser wavelength because of polystyrene’s absorption. In addition, UV laser irradiation is more localized and concentrated at the spot of laser irradiation, while hydrogen plasma irradiation results to a more uniform doping concentration even at low partial pressure and short irradiation time. Both UV laser and plasma irradiations can nevertheless be utilized to fabricate tritium-doped polystyrene targets for future laser fusion experiments. With a high doping rate and efficiency, a 1% tritium-doped polystyrene shell target having 7.6 × 10{sup 11} Bq g{sup −1} specific radioactivity can be obtained at a short period of time thereby decreasing tritium consumption and safety management costs.

  18. High power, short pulses ultraviolet laser for the development of a new x-ray laser

    International Nuclear Information System (INIS)

    Meixler, L.; Nam, C.H.; Robinson, J.; Tighe, W.; Krushelnick, K.; Suckewer, S.; Goldhar, J.; Seely, J.; Feldman, U.

    1989-04-01

    A high power, short pulse ultraviolet laser system (Powerful Picosecond-Laser) has been developed at the Princeton Plasma Physics Laboratory (PPPL) as part of experiments designed to generate shorter wavelength x-ray lasers. With the addition of pulse compression and a final KrF amplifier the laser output is expected to have reached 1/3-1/2 TW (10 12 watts) levels. The laser system, particularly the final amplifier, is described along with some initial soft x-ray spectra from laser-target experiments. The front end of the PP-Laser provides an output of 20--30 GW (10 9 watts) and can be focussed to intensities of /approximately/10 16 W/cm 2 . Experiments using this output to examine the effects of a prepulse on laser-target interaction are described. 19 refs., 14 figs

  19. Laser-pulsed Plasma Chemistry: Laser-initiated Plasma Oxidation Of Niobium

    OpenAIRE

    Marks R.F.; Pollak R.A.; Avouris Ph.; Lin C.T.; Thefaine Y.J.

    1983-01-01

    We report the first observation of the chemical modification of a solid surface exposed to an ambient gas plasma initiated by the interaction of laser radiation with the same surface. A new technique, which we designate laser-pulsed plasma chemistry (LPPC), is proposed for activating heterogeneous chemical reactions at solid surfaces in a gaseous ambient by means of a plasma initiated by laser radiation. Results for niobium metal in one atmosphere oxygen demonstrate single-pulse, self-limitin...

  20. Electron-beam-excited gas laser research

    International Nuclear Information System (INIS)

    Johnson, A.W.; Gerardo, J.B.; Patterson, E.L.; Gerber, R.A.; Rice, J.K.; Bingham, F.W.

    1975-01-01

    Net energy gain in laser fusion places requirements on the laser that are not realized by any existing laser. Utilization of relativistic electron beams (REB's), a relatively new source for the excitation of gas laser media, may lead to new lasers that could satisfy these requirements. Already REB's have been utilized to excite gas laser media and produce gas lasers that have not been produced as successfully any other way. Electron-beam-excitation has produced electronic-transition dimer lasers that have not yet been produced by any other excitation scheme (for example, Xe 2 / sup *(1)/, Kr:O(2 1 S)/sup 2/, KrF/sup *(3)/). In addition, REB's have initiated chemical reactions to produce HF laser radiation with unique and promising results. Relativistic-electron-beam gas-laser research is continuing to lead to new lasers with unique properties. Results of work carried out at Sandia Laboratories in this pioneering effort of electron-beam-excited-gas lasers are reviewed. (U.S.)

  1. Laser spark distribution and ignition system

    Science.gov (United States)

    Woodruff, Steven [Morgantown, WV; McIntyre, Dustin L [Morgantown, WV

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  2. Transcanalicular laser dacryocystorhinostomy using low energy 810 nm diode laser

    Directory of Open Access Journals (Sweden)

    Sanjiv K Gupta

    2012-01-01

    Conclusions: Transcanalicular Laser DCR can be safely performed using a low power 810 nm diode laser. The surgery is elegant, minimally invasive, allows fast rehabilitation, and has an excellent success rate.

  3. Improving Reliability of High Power Quasi-CW Laser Diode Arrays for Pumping Solid State Lasers

    Science.gov (United States)

    Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Baggott, Renee S.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.

    2005-01-01

    Most Lidar applications rely on moderate to high power solid state lasers to generate the required transmitted pulses. However, the reliability of solid state lasers, which can operate autonomously over long periods, is constrained by their laser diode pump arrays. Thermal cycling of the active regions is considered the primary reason for rapid degradation of the quasi-CW high power laser diode arrays, and the excessive temperature rise is the leading suspect in premature failure. The thermal issues of laser diode arrays are even more drastic for 2-micron solid state lasers which require considerably longer pump pulses compared to the more commonly used pump arrays for 1-micron lasers. This paper describes several advanced packaging techniques being employed for more efficient heat removal from the active regions of the laser diode bars. Experimental results for several high power laser diode array devices will be reported and their performance when operated at long pulsewidths of about 1msec will be described.

  4. Fs-laser processing of polydimethylsiloxane

    Energy Technology Data Exchange (ETDEWEB)

    Atanasov, Petar A., E-mail: paatanas@ie.bas.bg; Nedyalkov, Nikolay N. [Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Shose, Sofia 1784 (Bulgaria); Valova, Eugenia I.; Georgieva, Zhenya S.; Armyanov, Stefan A.; Kolev, Konstantin N. [Rostislaw Kaischew Institute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Block 11, Sofia 1113 (Bulgaria); Amoruso, Salvatore; Wang, Xuan; Bruzzese, Ricardo [CNR-SPIN, Dipartimento di Scienze Fisiche, Universita degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Sawczak, Miroslaw; Śliwiński, Gerard [Photophysics Department, The Szewalski Institute, Polish Academy of Sciences, 14 Fiszera St, 80-231 Gdańsk (Poland)

    2014-07-14

    We present an experimental analysis on surface structuring of polydimethylsiloxane films with UV (263 nm) femtosecond laser pulses, in air. Laser processed areas are analyzed by optical microscopy, SEM, and μ-Raman spectroscopy. The laser-treated sample shows the formation of a randomly nanostructured surface morphology. μ-Raman spectra, carried out at both 514 and 785 nm excitation wavelengths, prior and after laser treatment allow evidencing the changes in the sample structure. The influence of the laser fluence on the surface morphology is studied. Finally, successful electro-less metallization of the laser-processed sample is achieved, even after several months from the laser-treatment contrary to previous observation with nanosecond pulses. Our findings address the effectiveness of fs-laser treatment and chemical metallization of polydimethylsiloxane films with perspective technological interest in micro-fabrication devices for MEMS and nano-electromechanical systems.

  5. Random distributed feedback fibre lasers

    Energy Technology Data Exchange (ETDEWEB)

    Turitsyn, Sergei K., E-mail: s.k.turitsyn@aston.ac.uk [Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET (United Kingdom); Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Babin, Sergey A. [Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation); Churkin, Dmitry V. [Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET (United Kingdom); Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation); Vatnik, Ilya D.; Nikulin, Maxim [Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation); Podivilov, Evgenii V. [Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation)

    2014-09-10

    The concept of random lasers exploiting multiple scattering of photons in an amplifying disordered medium in order to generate coherent light without a traditional laser resonator has attracted a great deal of attention in recent years. This research area lies at the interface of the fundamental theory of disordered systems and laser science. The idea was originally proposed in the context of astrophysics in the 1960s by V.S. Letokhov, who studied scattering with “negative absorption” of the interstellar molecular clouds. Research on random lasers has since developed into a mature experimental and theoretical field. A simple design of such lasers would be promising for potential applications. However, in traditional random lasers the properties of the output radiation are typically characterized by complex features in the spatial, spectral and time domains, making them less attractive than standard laser systems in terms of practical applications. Recently, an interesting and novel type of one-dimensional random laser that operates in a conventional telecommunication fibre without any pre-designed resonator mirrors–random distributed feedback fibre laser–was demonstrated. The positive feedback required for laser generation in random fibre lasers is provided by the Rayleigh scattering from the inhomogeneities of the refractive index that are naturally present in silica glass. In the proposed laser concept, the randomly backscattered light is amplified through the Raman effect, providing distributed gain over distances up to 100 km. Although an effective reflection due to the Rayleigh scattering is extremely small (∼0.1%), the lasing threshold may be exceeded when a sufficiently large distributed Raman gain is provided. Such a random distributed feedback fibre laser has a number of interesting and attractive features. The fibre waveguide geometry provides transverse confinement, and effectively one-dimensional random distributed feedback leads to the

  6. Random distributed feedback fibre lasers

    International Nuclear Information System (INIS)

    Turitsyn, Sergei K.; Babin, Sergey A.; Churkin, Dmitry V.; Vatnik, Ilya D.; Nikulin, Maxim; Podivilov, Evgenii V.

    2014-01-01

    The concept of random lasers exploiting multiple scattering of photons in an amplifying disordered medium in order to generate coherent light without a traditional laser resonator has attracted a great deal of attention in recent years. This research area lies at the interface of the fundamental theory of disordered systems and laser science. The idea was originally proposed in the context of astrophysics in the 1960s by V.S. Letokhov, who studied scattering with “negative absorption” of the interstellar molecular clouds. Research on random lasers has since developed into a mature experimental and theoretical field. A simple design of such lasers would be promising for potential applications. However, in traditional random lasers the properties of the output radiation are typically characterized by complex features in the spatial, spectral and time domains, making them less attractive than standard laser systems in terms of practical applications. Recently, an interesting and novel type of one-dimensional random laser that operates in a conventional telecommunication fibre without any pre-designed resonator mirrors–random distributed feedback fibre laser–was demonstrated. The positive feedback required for laser generation in random fibre lasers is provided by the Rayleigh scattering from the inhomogeneities of the refractive index that are naturally present in silica glass. In the proposed laser concept, the randomly backscattered light is amplified through the Raman effect, providing distributed gain over distances up to 100 km. Although an effective reflection due to the Rayleigh scattering is extremely small (∼0.1%), the lasing threshold may be exceeded when a sufficiently large distributed Raman gain is provided. Such a random distributed feedback fibre laser has a number of interesting and attractive features. The fibre waveguide geometry provides transverse confinement, and effectively one-dimensional random distributed feedback leads to the

  7. Semiconductor Laser Diode Pumps for Inertial Fusion Energy Lasers

    International Nuclear Information System (INIS)

    Deri, R.J.

    2011-01-01

    Solid-state lasers have been demonstrated as attractive drivers for inertial confinement fusion on the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) and at the Omega Facility at the Laboratory for Laser Energetics (LLE) in Rochester, NY. For power plant applications, these lasers must be pumped by semiconductor diode lasers to achieve the required laser system efficiency, repetition rate, and lifetime. Inertial fusion energy (IFE) power plants will require approximately 40-to-80 GW of peak pump power, and must operate efficiently and with high system availability for decades. These considerations lead to requirements on the efficiency, price, and production capacity of the semiconductor pump sources. This document provides a brief summary of these requirements, and how they can be met by a natural evolution of the current semiconductor laser industry. The detailed technical requirements described in this document flow down from a laser ampl9ifier design described elsewhere. In brief, laser amplifiers comprising multiple Nd:glass gain slabs are face-pumped by two planar diode arrays, each delivering 30 to 40 MW of peak power at 872 nm during a ∼ 200 (micro)s quasi-CW (QCW) pulse with a repetition rate in the range of 10 to 20 Hz. The baseline design of the diode array employs a 2D mosaic of submodules to facilitate manufacturing. As a baseline, they envision that each submodule is an array of vertically stacked, 1 cm wide, edge-emitting diode bars, an industry standard form factor. These stacks are mounted on a common backplane providing cooling and current drive. Stacks are conductively cooled to the backplane, to minimize both diode package cost and the number of fluid interconnects for improved reliability. While the baseline assessment in this document is based on edge-emitting devices, the amplifier design does not preclude future use of surface emitting diodes, which may offer appreciable future cost reductions and

  8. Laser Safety Inspection Criteria

    International Nuclear Information System (INIS)

    Barat, K.

    2005-01-01

    A responsibility of the Laser Safety Officer (LSO) is to perform laser audits. The American National Standard Z136.1 Safe Use of Lasers references this requirement through several sections. One such reference is Section 1.3.2.8, Safety Features Audits, ''The LSO shall ensure that the safety features of the laser installation facilities and laser equipment are audited periodically to assure proper operation''. The composition, frequency and rigor of that inspection/audit rests in the hands of the LSO. A common practice for institutions is to develop laser audit checklists or survey forms It is common for audit findings from one inspector or inspection to the next to vary even when reviewing the same material. How often has one heard a comment, ''well this area has been inspected several times over the years and no one ever said this or that was a problem before''. A great number of audit items, and therefore findings, are subjective because they are based on the experience and interest of the auditor to particular items on the checklist. Beam block usage, to one set of eyes might be completely adequate, while to another, inadequate. In order to provide consistency, the Laser Safety Office of the National Ignition Facility Directorate has established criteria for a number of items found on the typical laser safety audit form. The criteria are distributed to laser users. It serves two broad purposes; first, it gives the user an expectation of what will be reviewed by an auditor. Second, it is an opportunity to explain audit items to the laser user and thus the reasons for some of these items, such as labelling of beam blocks

  9. High power ultrashort pulse lasers

    International Nuclear Information System (INIS)

    Perry, M.D.

    1994-01-01

    Small scale terawatt and soon even petawatt (1000 terawatt) class laser systems are made possible by application of the chirped-pulse amplification technique to solid-state lasers combined with the availability of broad bandwidth materials. These lasers make possible a new class of high gradient accelerators based on the large electric fields associated with intense laser-plasma interactions or from the intense laser field directly. Here, we concentrate on the laser technology to produce these intense pulses. Application of the smallest of these systems to the production of high brightness electron sources is also introduced

  10. PbSnTe injection lasers

    International Nuclear Information System (INIS)

    Oron, M.

    1982-03-01

    Carrier confined homostructure PbSnTe lasers were developed and investigated. In this laser structure good electrical and optical confinement can be achieved by a suitable carrier concentration profile. The advantage of these lasers over PbSnTe heterostructure lasers is the perfect lattice matching between the various layers of the structure. The desired carrier concentration profile was achieved by the growth of several epitaxial layers by the LPE method on a suitable substrate. The performance of these lasers was compared with that of previous homostructure and double heterostructure lasers. (H.K.)

  11. Laser induced energy transfer

    International Nuclear Information System (INIS)

    Falcone, R.W.

    1979-01-01

    Two related methods of rapidly transferring stored energy from one excited chemical species to another are described. The first of these, called a laser induced collision, involves a reaction in which the energy balance is met by photons from an intense laser beam. A collision cross section of ca 10 - 17 cm 2 was induced in an experiment which demonstrated the predicted dependence of the cross section on wavelength and power density of the applied laser. A second type of laser induced energy transfer involves the inelastic scattering of laser radiation from energetically excited atoms, and subsequent absorption of the scattered light by a second species. The technique of producing the light, ''anti-Stokes Raman'' scattering of visible and infrared wavelength laser photons, is shown to be an efficient source of narrow bandwidth, high brightness, tunable radiation at vacuum ultraviolet wavelengths by using it to excite a rare gas transition at 583.7 A. In addition, this light source was used to make the first measurement of the isotopic shift of the helium metastable level at 601 A. Applications in laser controlled chemistry and spectroscopy, and proposals for new types of lasers using these two energy transfer methods are discussed

  12. 5. Laser plasma interaction

    International Nuclear Information System (INIS)

    Labaune, C.; Fuchs, J.; Bandulet, H.

    2002-01-01

    Imprint elimination, smoothing and preheat control are considerable problems in inertial fusion and their possible solution can be achieved by using low-density porous materials as a buffer in target design. The articles gathered in this document present various aspects of the laser-plasma interaction, among which we have noticed: -) numerical algorithmic improvements of the Vlasov solver toward the simulation of the laser-plasma interaction are proposed, -) the dependence of radiation temperatures and X-ray conversion efficiencies of hohlraum on the target structures and laser irradiation conditions are investigated, -) a study of laser interaction with ultra low-density (0,5 - 20 mg/cm 3 ) porous media analyzing backscattered light at incident laser frequency ω 0 and its harmonics 3*ω 0 /2 and 2*ω 0 is presented, -) investigations of laser interaction with solid targets and crater formation are carried out with the objective to determine the ablation loading efficiency, -) a self organization in an intense laser-driven plasma and the measure of the relative degree of order of the states in an open system based on the S-theorem are investigated, and -) the existence and stability of electromagnetic solitons generated in a relativistic interaction of an intense laser light with uniform under-dense cold plasma are studied

  13. The Application of Cryogenic Laser Physics to the Development of High Average Power Ultra-Short Pulse Lasers

    Directory of Open Access Journals (Sweden)

    David C. Brown

    2016-01-01

    Full Text Available Ultrafast laser physics continues to advance at a rapid pace, driven primarily by the development of more powerful and sophisticated diode-pumping sources, the development of new laser materials, and new laser and amplification approaches such as optical parametric chirped-pulse amplification. The rapid development of high average power cryogenic laser sources seems likely to play a crucial role in realizing the long-sought goal of powerful ultrafast sources that offer concomitant high peak and average powers. In this paper, we review the optical, thermal, thermo-optic and laser parameters important to cryogenic laser technology, recently achieved laser and laser materials progress, the progression of cryogenic laser technology, discuss the importance of cryogenic laser technology in ultrafast laser science, and what advances are likely to be achieved in the near-future.

  14. Experimental verification of subthreshold laser therapy using conventional pattern scan laser.

    Directory of Open Access Journals (Sweden)

    Tomoyasu Shiraya

    Full Text Available Leading-edge therapeutic laser technologies are not available at every medical facility; therefore, alternative approaches incorporating novel advances in digital and laser technology into more readily available conventional methods have generated significant research interest. Using a rabbit model, this study investigated whether the algorithm used in the Endpoint Management (EM software system of the latest devices could enable subthreshold laser treatment in conventional retinal tissue laser therapy systems.Two types of devices were used, the PASCAL Streamline 577 and the MC 500-Vixi™, and the laser method was classified into three categories: EM; single-shot using PASCAL with arbitrary energy settings (PSS-SDM; and MC500-VixiTM (VX-SDM, which were performed in eight eyes from four Dutch-Belted rabbits. In EM, 100 mW (100% was set as a landmark, and the laser energy parameters were gradually decreased to 80%, 60%, 50%, 40%, 30%, 20%, and 10%, using a 2 × 3 square pattern. In PSS-SDM and VX-SDM, as control, the laser energy was gradually decreased to 100, 80, 60, 50, 40, 30, 20, and 10 mW. The laser settings were fixed at 200 μm, 20 ms, and a wavelength of 577 μm. To identify and compare the extent of tissue damage at each spot size, optical coherence tomography (OCT and histological findings were used to construct a three-dimensional histopathology image using a confocal laser scanning fluorescence microscope.The spot size at 50% setting on EM was 7183 μm2; PSS-SDM required 50 mW (5503 μm2 to 60 mW (10279 μm2 and VX-SDM required 50 mW (7423 μm2 to create the approximate spot size. Furthermore, at 50 mW of PSS-SDM and VX-SDM, the extent of tissue damage in all three methods was generally in accord with the outer nuclear layer by OCT and inner nuclear layer by histopathological imaging.These findings suggest that it may be possible to perform subthreshold laser therapy using approximations from the EM algorithm.

  15. Photon technology. Laser processing technology; Photon technology. Laser process gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Survey has been conducted to develop laser processing technology utilizing the interaction between substance and photon. This is a part of the leading research on photon technology development. The photon technology development is aimed at novel technology development highly utilizing the quantum nature of photons. In the field of laser processing, high quality photons are used as tools, special functions of atoms and molecules will be discovered, and processing for functional fabrication (photon machining) will be established. A role of laser processing in industries has become significant, which is currently spreading not only into cutting and welding of materials and scalpels but also into such a special field as ultrafine processing of materials. The spreading is sometimes obstructed due to the difficulty of procurement of suitable machines and materials, and the increase of cost. The purpose of this study is to develop the optimal laser technology, to elucidate the interaction between substance and photon, and to develop the laser system and the transmission and regulation systems which realize the optimal conditions. 387 refs., 115 figs., 25 tabs.

  16. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  17. Micron-scale resolution radiography of laser-accelerated and laser-exploded foils using an yttrium x-ray laser

    International Nuclear Information System (INIS)

    Cauble, R.; Da Silva, L.B.; Barbee, T.W. Jr.; Celliers, P.; Moreno, J.C.; Mrowka, S.; Perry, T.S.; Wan, A.S.

    1994-09-01

    The authors have imaged laser-accelerated foils and exploding foils on the few-micron scale using an yttrium x-ray laser (155 angstrom, 80 eV, ∼200 ps duration) and a multilayer mirror imaging system. At the maximum magnification of 30, resolution was of order one micron. The images were side-on radiographs of the foils. Accelerated foils showed significant filamentation on the rear-side (away from the driving laser) of the foil, although the laser beam was smoothed. In addition to the narrow rear-side filamentation, some shots revealed larger-scale plume-like structures on the front (driven) side of the Al foil. These plumes seem to be little-affected by beam smoothing and are likely a consequence of Rayleigh-Taylor instability. The experiments were carried out at the Nova two-beam facility

  18. Experimental comparison of laser energy losses in high-quality laser-oxygen cutting of low-carbon steel using radiation from fibre and CO{sub 2} lasers

    Energy Technology Data Exchange (ETDEWEB)

    Golyshev, A A; Malikov, A G; Orishich, A M; Shulyat' ev, V B [S.A. Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2015-09-30

    We report a comparative experimental study of laseroxygen cutting of low-carbon steel using a fibre laser with a wavelength of 1.07 μm and a CO{sub 2} laser with a wavelength of 10.6 μm at the sheet thickness of 3 – 16 mm. For the two lasers we have measured the dependence of the cutting speed on the radiation power and determined the cutting speed at which the surface roughness is minimal. The coefficient of laser radiation absorption in the laser cutting process is measured for these lasers at different values of the cutting speed and radiation power. It is found that the minimal roughness of the cut surface is reached at the absorbed laser energy per unit volume of the removed material, equal to 11 – 13 J mm{sup -3}; this value is the same for the two lasers and does not depend on the sheet thickness. (laser technologies)

  19. Laser desorption ionization and peptide sequencing on laser induced silicon microcolumn arrays

    Science.gov (United States)

    Vertes, Akos [Reston, VA; Chen, Yong [San Diego, CA

    2011-12-27

    The present invention provides a method of producing a laser-patterned silicon surface, especially silicon wafers for use in laser desorption ionization (LDI-MS) (including MALDI-MS and SELDI-MS), devices containing the same, and methods of testing samples employing the same. The surface is prepared by subjecting a silicon substrate to multiple laser shots from a high-power picosecond or femtosecond laser while in a processing environment, e.g., underwater, and generates a remarkable homogenous microcolumn array capable of providing an improved substrate for LDI-MS.

  20. 1982 laser program annual report

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, C.D.; Grow, G.R. (eds.)

    1983-08-01

    This annual report covers the following eight sections: (1) laser program review, (2) laser systems and operation, (3) target design, (4) target fabrication, (5) fusion experiments program, (6) Zeus laser project, (7) laser research and development, and (8) energy applications. (MOW)

  1. 1982 laser program annual report

    International Nuclear Information System (INIS)

    Hendricks, C.D.; Grow, G.R.

    1983-08-01

    This annual report covers the following eight sections: (1) laser program review, (2) laser systems and operation, (3) target design, (4) target fabrication, (5) fusion experiments program, (6) Zeus laser project, (7) laser research and development, and (8) energy applications

  2. Laser induced magnetization switching in a TbFeCo ferrimagnetic thin film: discerning the impact of dipolar fields, laser heating and laser helicity by XPEEM

    International Nuclear Information System (INIS)

    Gierster, L.; Ünal, A.A.; Pape, L.; Radu, F.; Kronast, F.

    2015-01-01

    We investigate laser induced magnetic switching in a ferrimagnetic thin film of Tb_2_2Fe_6_9Co_9 by PEEM. Using a small laser beam with a spot size of 3–5 µm in diameter in combination with high resolution magnetic soft X-ray microscopy we are able to discriminate between different effects that govern the microscopic switching process, namely the influence of the laser heating, of the helicity dependent momentum transfer, and of the dipolar coupling. Applying a sequence of femtosecond laser pulses to a previously saturated TbFeCo film leads to the formation of ring shaped magnetic structures in which all three effects can be observed. Laser helicity assisted switching is only observed in a narrow region within the Gaussian profile of the laser spot. Whereas in the center of the laser spot we find clear evidence for thermal demagnetization and in the outermost areas magnetic switching is determined by dipolar coupling with the surrounding film. Our findings demonstrate that by reducing the laser spot size the influence of dipolar coupling on laser induced switching is becoming increasingly important. - Highlights: • With a new PEEM sample holder a laser spot size of 3–5 µm in diameter is reached. • Spatial resolved imaging of laser induced magnetization reversal. • A single femtosecond laser pulse leads to a multi-domain state in TbFeCo. • A pulse sequence results in a ring-shaped magnetic pattern caused by dipolar fields. • Laser helicity dependent effects appear only in a narrow fluence region.

  3. Advanced lasers laser physics and technology for applied and fundamental science

    CERN Document Server

    Sukhoivanov, Igor

    2015-01-01

    Presenting a blend of applied and fundamental research in highly interdisciplinary subjects of rapidly developing areas, this book contains contributions on the frontiers and hot topics of laser physics, laser technology and laser engineering, and covers a wide range of laser topics, from all-optical signal processing and chaotic optical communication to production of superwicking surfaces, correction of extremely high-power beams, and generation of ultrabroadband spectra. It presents both review-type contributions and well researched and documented case studies, and is intended for graduate students, young scientist, and emeritus scientist working/studying in laser physics, optoelectronics, optics, photonics, and adjacent areas. The book contains both experimental and theoretical studies, as well as combinations of these two, which is known to be a most useful and interesting form of reporting scientific results, allowing students to really learn from each contribution. The book contains over 130 illustratio...

  4. Optical properties of tin oxide nanoparticles prepared by laser ablation in water: Influence of laser ablation time duration and laser fluence

    International Nuclear Information System (INIS)

    Desarkar, Himadri Sankar; Kumbhakar, P.; Mitra, A.K.

    2012-01-01

    Colloidal tin oxide nanoparticles are prepared by laser (having a wavelength of 1064 nm) ablation of tin metallic target immersed in pure deionized water. The influences of laser ablation time and laser fluence on the size and optical properties of the synthesized nanoparticles are studied. Prepared tin oxide nanoparticles are characterized by transmission electron microscope, selected area electron diffraction and UV–Visible absorption spectroscopy. The morphology of prepared tin oxide nanoparticles is found to be mostly spherical and with sizes in the nanometric range (mean radius of 3.2 to 7.3 nm). The measured UV–Visible absorption spectra show the presence of absorption peaks in the ultraviolet region. The band gap energy of samples prepared with different laser ablation time duration is calculated and is found to be increased with decrease in size (radius) of the prepared nanoparticles. Photoluminescence emission measurements at room temperature show that all the samples exhibit photoluminescence in the visible region. The peak photoluminescence emission intensity in the sample prepared with 50 min of laser ablation time is 3.5 times larger than that obtained in the sample prepared with 10 min of laser ablation time. - Highlights: ► SnO 2 nanoparticles (6.4–14.6 nm) are prepared by laser ablation in liquid technique. ► The influences of laser ablation time and laser fluence are studied. ► Samples are characterized by TEM and UV–Visible absorption spectroscopy. ► UV–Visible absorption spectra exhibit quantum confinement effect. ► Samples exhibit enhanced photoluminescence emissions in the visible region.

  5. Laser Refractography

    CERN Document Server

    Rinkevichyus, B.S; Raskovskaya, I.L

    2010-01-01

    This book describes the basic principles of laser refractography, a flexible new diagnostic tool for measuring optically inhomogeneous media and flows. Laser refractography is based on digital imaging and computer processing of structured laser beam refraction (SLR) in inhomogeneous transparent media. Laser refractograms provide both qualitative and quantitative measurements and can be used for the study of fast and transient processes. In this book, the theoretical basis of refractography is explored in some detail, and experimental setups are described for measurement of transparent media using either 2D (passed radiation) or 3D (scattered radiation) refractograms. Specific examples and applications are discussed, including visualization of the boundary layer near a hot or cold metallic ball in water, and observation of edge effects and microlayers in liquids and gases. As the first book to describe this new and exciting technique, this monograph has broad cross-disciplinary appeal and will be of interest t...

  6. Risks induced by laser radiation; Risques induits par le rayonnement laser

    Energy Technology Data Exchange (ETDEWEB)

    Courant, D [CEA Fontenay-aux-Roses, 92 (France). Dept. de Radiobiologie et de Radiopathologie

    2001-07-01

    The use of lasers is often dangerous because of the emitted power, the wave length, the conduction system(optical fiber, wave guide, mirrors) and the use conditions. The safety notion involves the precise knowledge of materials, the biological effects in function of laser emission parameters, the knowledge of protection standards, the observance of use rules and the personnel training. This chapter treats the risks induced by the beam. It gives the different biological effects induced by the laser beam, at the eye and skin levels that are at the origin of exposure limits and the lasers classification recommended by the protection standards. (N.C.)

  7. Guiding of laser pulses in plasma waveguides created by linearly-polarized femtosecond laser pulses

    OpenAIRE

    Lemos, N.; Cardoso, L.; Geada, J.; Figueira, G.; Albert, F.; Dias, J. M.

    2018-01-01

    We experimentally demonstrate that plasma waveguides produced with ultra-short laser pulses (sub-picosecond) in gas jets are capable of guiding high intensity laser pulses. This scheme has the unique ability of guiding a high-intensity laser pulse in a plasma waveguide created by the same laser system in the very simple and stable experimental setup. A hot plasma column was created by a femtosecond class laser that expands into an on-axis parabolic low density profile suitable to act as a wav...

  8. Predictive modeling, simulation, and optimization of laser processing techniques: UV nanosecond-pulsed laser micromachining of polymers and selective laser melting of powder metals

    Science.gov (United States)

    Criales Escobar, Luis Ernesto

    One of the most frequently evolving areas of research is the utilization of lasers for micro-manufacturing and additive manufacturing purposes. The use of laser beam as a tool for manufacturing arises from the need for flexible and rapid manufacturing at a low-to-mid cost. Laser micro-machining provides an advantage over mechanical micro-machining due to the faster production times of large batch sizes and the high costs associated with specific tools. Laser based additive manufacturing enables processing of powder metals for direct and rapid fabrication of products. Therefore, laser processing can be viewed as a fast, flexible, and cost-effective approach compared to traditional manufacturing processes. Two types of laser processing techniques are studied: laser ablation of polymers for micro-channel fabrication and selective laser melting of metal powders. Initially, a feasibility study for laser-based micro-channel fabrication of poly(dimethylsiloxane) (PDMS) via experimentation is presented. In particular, the effectiveness of utilizing a nanosecond-pulsed laser as the energy source for laser ablation is studied. The results are analyzed statistically and a relationship between process parameters and micro-channel dimensions is established. Additionally, a process model is introduced for predicting channel depth. Model outputs are compared and analyzed to experimental results. The second part of this research focuses on a physics-based FEM approach for predicting the temperature profile and melt pool geometry in selective laser melting (SLM) of metal powders. Temperature profiles are calculated for a moving laser heat source to understand the temperature rise due to heating during SLM. Based on the predicted temperature distributions, melt pool geometry, i.e. the locations at which melting of the powder material occurs, is determined. Simulation results are compared against data obtained from experimental Inconel 625 test coupons fabricated at the National

  9. Surface hardening using cw CO2 laser: laser heat treatment, modelation, and experimental work

    Science.gov (United States)

    Muniz, German; Alum, Jorge

    1996-02-01

    In the present work are given the results of the application of laser metal surface hardening techniques using a cw carbon dioxide laser as an energy source on steel 65 G. The laser heat treatment results are presented theoretically and experimentally. Continuous wave carbon dioxide laser of 0.6, 0.3, and 0.4 kW were used. A physical model for the descriptions of the thermophysical laser metal interactions process is given and a numerical algorithm is used to solve this problem by means of the LHT code. The results are compared with the corresponding experimental ones and a very good agreement is observed. The LHT code is able to do predictions of transformation hardening by laser heating. These results will be completed with other ones concerning laser alloying and cladding presented in a second paper.

  10. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Science.gov (United States)

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    Background and objectives The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal. Study design and methods A PubMed search was conducted using the term “picosecond” combined with “laser”, “dermatology”, and “laser tattoo removal”. Results A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Conclusion Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments. PMID:27194919

  11. The KAERI laser facility with temporal laser beam shaping for application's user

    International Nuclear Information System (INIS)

    Hong, Sung Ki; Kim, Min Suk; Kim, Young Won; Ko, Kwanghoon; Lim, Changhwan; Seo, Young Seok

    2008-01-01

    The Korea Atomic Energy Research Institute(KAERI)has been developed a high energy Nd:Glass laser facility(KLF)for fast ignition research and high energy physics applications at early 2008. Now, we are researching the temporal laser beam shaping for application's user. The temporal laser beam shaping has been applied to a number of industrial applications. The KLF beam shaping system with fiber based consists of two electro optic modulator with DC bias using a Mach Zehnder interferometer, an arbitrary electronic waveform generator, a continuous wavelength fiber laser source, a fiber based pulse amplification system and DC bias source to generate temporally shaped pulses with a high extinction ratio and high resolution. RF signal waveform user defined by an arbitrary electronic waveform generator is only connected to one electro optic modulator. DC bias source with auto feed back or manual controller is connected both two electro optic modulators. Emitting laser light from a continuous wavelength fiber laser source is modulated to meet a user defined laser pulse with a high extinction ratio by two electro optic modulators. Experimental results are shown in Fig.1. Figure 1(a)shows two programmed waveforms with the signal width 10ns in an arbitrary electronic waveform generator. Figure 1(b)shows output laser pulses with sub mJ energy from amplification results of the KLF beam shaping system which can control the pulse width ranges from 400ps to sub us

  12. Therapeutic application of lasers in ophthalmology

    International Nuclear Information System (INIS)

    Misiuk-Hojlo, M.; Krzyzanowska-Berkowska, P.; Hill-Bator, A.

    2007-01-01

    Lasers have found application in diverse branches of medicine. In ophthalmology, laser technology has various therapeutic and diagnostic applications. The purpose of this article is to review the major therapeutic applications of lasers in different eye disorders. The effects of lasers on biological tissues and different laser techniques as well as the indications for laser therapy in various parts of the eye are discussed. Lasers are used to treat glaucoma and many vascular disorders of the retina. Laser treatment may be useful in preventing the development of neovascularization in diabetic retinopathy, BRVO, or CRVO. Laser techniques are also available for the treatment of the exudative form of age-related macular degeneration (AMD) and some malignant and benign intraocular tumors and in retina abnormalities which predispose to rhegmatogenous retinal detachment. Corneal laser surgery is the most frequently applied laser procedure in ophthalmology. PRK, LASIK, and LASEK are used to correct errors in vision such as myopia, hyperopia, and astigmatism. Laser photocoagulation is also helpful in cataract surgery. Nowadays, lasers have become so universal that it is difficult to imagine ophthalmology without them. We are still witnessing rapid advances in the development of laser techniques, especially in plastic surgery, cataract extraction, and ocular imaging. (authors)

  13. Coupled optical resonance laser locking.

    Science.gov (United States)

    Burd, S C; du Toit, P J W; Uys, H

    2014-10-20

    We have demonstrated simultaneous laser frequency stabilization of a UV and IR laser, to coupled transitions of ions in the same spectroscopic sample, by detecting only the absorption of the UV laser. Separate signals for locking the different lasers are obtained by modulating each laser at a different frequency and using lock-in detection of a single photodiode signal. Experimentally, we simultaneously lock a 369 nm and a 935 nm laser to the (2)S(1/2) → (2)(P(1/2) and (2)D(3/2) → (3)D([3/2]1/2) transitions, respectively, of Yb(+) ions generated in a hollow cathode discharge lamp. Stabilized lasers at these frequencies are required for cooling and trapping Yb(+) ions, used in quantum information and in high precision metrology experiments. This technique should be readily applicable to other ion and neutral atom systems requiring multiple stabilized lasers.

  14. Laser cladding of turbine blades

    International Nuclear Information System (INIS)

    Shepeleva, L.; Medres, B.; Kaplan, W.D.; Bamberger, M.

    2000-01-01

    A comparative study of two different techniques for the application of wear-resistant coatings for contact surfaces of shroud shelves of gas turbine engine blades (GTE) has been conducted. Wear-resistant coatings were applied on In713 by laser cladding with direct injection of the cladding powder into the melt pool. Laser cladding was conducted with a TRUMPF-2500, CW-CO 2 laser. The laser cladding was compared with commercially available plasma cladding with wire. Both plasma and laser cladded zones were characterized by optical and scanning electron microscopy. It was found that the laser cladded zone has a higher microhardness value (650-820 HV) compared with that of the plasma treated material (420-440 HV). This is a result of the significant reduction in grain size in the case of laser cladding. Unlike the plasma cladded zones, the laser treated material is free of micropores and microcracks. (orig.)

  15. Lasers for switched-power linacs

    International Nuclear Information System (INIS)

    Bigio, I.J.

    1988-01-01

    Laser-switched power surges for particle accelerators, just as with direct laser-driven accelerator schemes, place unique demands on the specifications of the invoked laser systems. We review the laser requirements for switched power sources of the types described in other chapters of this volume. The relative advantages and disadvantages of selected lasers are listed, and the appropriateness and scalability of existing technology is discussed. 4 refs., 2 figs., 2 tabs

  16. Naturlig ventilation i enfamiliehuse

    DEFF Research Database (Denmark)

    Bergsøe, N.C.

    Meddelelsen beskriver resultaterne af en række beregninger foretaget ved anvendelse af et computerprogram. Beregningerne har til formål at belyse forskellige parametres indvirkning på funktionen af et naturligt ventilationssystem. Blandt andet belyses systemets afhængighed af aftrækskanalernes di...... dimension, udeluftventilarealet og placeringen af aftrækskanalernes udmunding i tagfladen. Derudover gengives i kortfattet form de væsentligste konklusioner af udvalgte publikationer, som behandler særlige forhold vedrørende naturlig ventilation i praksis....

  17. Laser plant "Iguana" for transmyocardial revascularization based on kW-level waveguide CO2 laser

    Science.gov (United States)

    Panchenko, Vladislav Y.; Bockeria, L. A.; Berishvili, I. I.; Vasiltsov, Victor V.; Golubev, Vladimir S.; Ul'yanov, Valery A.

    2001-05-01

    For many years the Institute on Laser and Information Technologies RAN has been developing a concept of high-power industrial CO2 lasers with diffusion cooling of the working medium. The paper gives a description of the laser medical system Iguana for transmyocardial laser revascularization (TMLR) as an example of various applications of high-power waveguide CO2 lasers. The clinical results of the TMLR method application in surgical treatment are presented. The methods of determination of the time, when the laser beam passes through the demarcation line between myocardium tissue and blood, are discussed.

  18. 2 micron femtosecond fiber laser

    Science.gov (United States)

    Liu, Jian; Wan, Peng; Yang, Lihmei

    2014-07-29

    Methods and systems for generating femtosecond fiber laser pulses are disclose, including generating a signal laser pulse from a seed laser oscillator; using a first amplifier stage comprising an input and an output, wherein the signal laser pulse is coupled into the input of the first stage amplifier and the output of the first amplifier stage emits an amplified and stretched signal laser pulse; using an amplifier chain comprising an input and an output, wherein the amplified and stretched signal laser pulse from the output of the first amplifier stage is coupled into the input of the amplifier chain and the output of the amplifier chain emits a further amplified, stretched signal laser pulse. Other embodiments are described and claimed.

  19. Dual-channel amplification in a single-mode diode laser for multi-isotope laser cooling

    International Nuclear Information System (INIS)

    Booth, James L.; Van Dongen, Janelle; Lebel, Paul; Klappauf, Bruce G.; Madison, Kirk W.

    2007-01-01

    The output from two grating-stabilized external-cavity diode lasers were injected into a single-mode diode laser. Operating at a wavelength of 780 nm, this laser produced ∼50 mW of power with two main frequency components of the same spectral characteristics of the seed lasers. The power ratio of the amplified components was freely adjustable due to gain saturation, and amplification was observed for frequency differences of the two seed lasers in the range from 73 MHz to 6.6 GHz. This system was used to realize a dual isotope magneto-optic trap (MOT) for rubidium ( 85 Rb and 87 Rb). The resulting position and cloud size of the dual isotope MOT was the same as that of the single species MOTs to within ±10 and ±20 μm, respectively. We also characterized the additional spectral components produced by four wave mixing (FWM) in the diode laser amplifier and utilized a particular FWM sideband to realize hyperfine pumping and subsequent laser trapping of 85 Rb in the absence of a 'repump' laser dedicated to hyperfine pumping

  20. Design of pulsed laser diode drive power for ZY3(02) laser altimeter

    Science.gov (United States)

    Feng, Wen; Li, Mingshan; Meng, Peibei; Yan, Fanjiang; Li, Xu; Wang, Chunhui

    2017-11-01

    Solid laser pumped by semiconductor laser has the large value in the area of space laser technology, because of the advantages of high efficiency, small volume and long life. As the indispensable component of laser, laser power is also very important. Combined with ZY3(02) laser altimeter project, a high voltage(0-300V), high current(0-80A), long pulse width(0-230us) and high precision temperature semiconductor laser power is developed. IGBT is applied in the driving circuit as the switch to provide a current pulse for LD. The heating or cooling capacity of TEC is controlled by PID compensation circuit quickly adjusts the duty cycle of the UC1637 PWM signal, to realize the high accuracy controlling of LD working temperature. The tests in the external ambient temperature of 5°C, 20°C, 30°C show that the LD current pulse is stable and the stability of LD working temperature up to +/-0.1°C around the set point temperature, which ensure the highly stable operation of DPL.

  1. Laser fusion overview

    International Nuclear Information System (INIS)

    Nuckolls, J.

    1976-01-01

    Because of recent breakthroughs in the target area, and in the glass laser area, the scientific feasibility of laser fusion--and of inertial fusion--may be demonstrated in the early 1980's. Then the development in that time period of a suitable laser (or storage ring or other driving source) would make possible an operational inertial fusion reactor in this century. These are roughly the same time scales as projected by the Tokamak magnetic confinement approach. It thus appears that the 15-20 year earlier start by magnetic confinement fusion may be overcome. Because inertial confinement has been demonstrated, and inertial fusion reactors may operate on smaller scales than Tokamaks, laser fusion may have important technical and economic advantages

  2. Compact semiconductor lasers

    CERN Document Server

    Yu, Siyuan; Lourtioz, Jean-Michel

    2014-01-01

    This book brings together in a single volume a unique contribution by the top experts around the world in the field of compact semiconductor lasers to provide a comprehensive description and analysis of the current status as well as future directions in the field of micro- and nano-scale semiconductor lasers. It is organized according to the various forms of micro- or nano-laser cavity configurations with each chapter discussing key technical issues, including semiconductor carrier recombination processes and optical gain dynamics, photonic confinement behavior and output coupling mechanisms, carrier transport considerations relevant to the injection process, and emission mode control. Required reading for those working in and researching the area of semiconductors lasers and micro-electronics.

  3. The chirped-pulse inverse free-electron laser: A high-gradient vacuum laser accelerator

    International Nuclear Information System (INIS)

    Hartemann, F.V.; Landahl, E.C.; Troha, A.L.; Van Meter, J.R.; Baldis, H.A.; Freeman, R.R.; Luhmann, N.C. Jr.; Song, L.; Kerman, A.K.; Yu, D.U.

    1999-01-01

    The inverse free-electron laser (IFEL) interaction is studied theoretically and computationally in the case where the drive laser intensity approaches the relativistic regime, and the pulse duration is only a few optical cycles long. The IFEL concept has been demonstrated as a viable vacuum laser acceleration process; it is shown here that by using an ultrashort, ultrahigh-intensity drive laser pulse, the IFEL interaction bandwidth and accelerating gradient are increased considerably, thus yielding large energy gains. Using a chirped pulse and negative dispersion focusing optics allows one to take further advantage of the laser optical bandwidth and produce a chromatic line focus maximizing the gradient. The combination of these novel ideas results in a compact vacuum laser accelerator capable of accelerating picosecond electron bunches with a high gradient (GeV/m) and very low energy spread. copyright 1999 American Institute of Physics

  4. Efficient laser-diode end-pumped Nd:GGG lasers at 1054 and 1067 nm.

    Science.gov (United States)

    Xu, Bin; Xu, Huiying; Cai, Zhiping; Camy, P; Doualan, J L; Moncorgé, R

    2014-10-10

    Efficient and compact laser-diode end-pumped Nd:GGG simultaneous multiwavelength continuous-wave lasers at ∼1059, ∼1060 and ∼1062  nm were first demonstrated in a free-running 30 mm plano-concave laser cavity. The maximum output power was up to 3.92 W with a slope efficiency of about 53.6% with respect to the absorbed pump power. By inserting a 0.1 mm optical glass plate acting as a Fabry-Pérot etalon, a single-wavelength laser at ∼1067  nm with a maximum output power of 1.95 W and a slope efficiency of 28.5% can be obtained. Multiwavelength lasers, including those at ∼1054 or ∼1067  nm, were also achievable by suitably tilting the glass etalon. These simultaneous multiwavelength lasers provide a potential source for terahertz wave generation.

  5. Laser streaming: Turning a laser beam into a flow of liquid.

    Science.gov (United States)

    Wang, Yanan; Zhang, Qiuhui; Zhu, Zhuan; Lin, Feng; Deng, Jiangdong; Ku, Geng; Dong, Suchuan; Song, Shuo; Alam, Md Kamrul; Liu, Dong; Wang, Zhiming; Bao, Jiming

    2017-09-01

    Transforming a laser beam into a mass flow has been a challenge both scientifically and technologically. We report the discovery of a new optofluidic principle and demonstrate the generation of a steady-state water flow by a pulsed laser beam through a glass window. To generate a flow or stream in the same path as the refracted laser beam in pure water from an arbitrary spot on the window, we first fill a glass cuvette with an aqueous solution of Au nanoparticles. A flow will emerge from the focused laser spot on the window after the laser is turned on for a few to tens of minutes; the flow remains after the colloidal solution is completely replaced by pure water. Microscopically, this transformation is made possible by an underlying plasmonic nanoparticle-decorated cavity, which is self-fabricated on the glass by nanoparticle-assisted laser etching and exhibits size and shape uniquely tailored to the incident beam profile. Hydrophone signals indicate that the flow is driven via acoustic streaming by a long-lasting ultrasound wave that is resonantly generated by the laser and the cavity through the photoacoustic effect. The principle of this light-driven flow via ultrasound, that is, photoacoustic streaming by coupling photoacoustics to acoustic streaming, is general and can be applied to any liquid, opening up new research and applications in optofluidics as well as traditional photoacoustics and acoustic streaming.

  6. Laser-assisted fabrication of materials

    CERN Document Server

    Manna, Indranil

    2013-01-01

    Laser assisted fabrication involves shaping of materials using laser as a source of heat. It can be achieved by removal of materials (laser assisted cutting, drilling, etc.), deformation (bending, extrusion), joining (welding, soldering) and addition of materials (surface cladding or direct laser cladding). This book on ´Laser assisted Fabrication’ is aimed at developing in-depth engineering concepts on various laser assisted macro and micro-fabrication techniques with the focus on application and a review of the engineering background of different micro/macro-fabrication techniques, thermal history of the treated zone and microstructural development and evolution of properties of the treated zone.

  7. Laser safety in the lab

    CERN Document Server

    Barat, Ken L

    2012-01-01

    There is no more challenging setting for laser use than a research environment. In almost every other setting the laser controls count on engineering controls, and human exposure is kept to a minimum. In research, however, the user often manipulates the optical layout and thereby places him or herself in peril, but this does not mean that accidents and injury are unavoidable. On the contrary, laser accidents can be avoided by following a number of simple approaches. [i]Laser Safety in the Lab[/i] provides the laser user and laser safety officer with practical guidelines from housekeeping to ey

  8. Laser spectroscopy on organic molecules.

    Science.gov (United States)

    Imasaka, T

    1996-06-01

    Various laser spectrometric methods have been developed until now. Especially, laser fluorometry is most sensitive and is frequently combined with a separation technique such as capillary electrophoresis. For non-fluorescent compounds, photothermal spectrometry may be used instead. A diode laser is potentially useful for practical trace analysis, because of its low cost and long-term trouble-free operation. On the other hand, monochromaticity of the laser is essential in high-resolution spectrometry, e.g. in low temperature spectrometry providing a very sharp spectral feature. Closely-related compounds such as isomers can easily be differentiated, and information for assignment is obtained from the spectrum. Multiphoton ionization mass spectrometry is useful for soft ionization, providing additional information concerned with molecular weight and chemical structure. A short laser pulse with a sufficient energy is suitable for rapid heating of the solid surface. A matrix-assisted laser desorption/ion-ization technique is recently employed for introduction of a large biological molecule into a vacuum for mass analysis. In the future, laser spectrometry will be developed by a combination with state-of-the-art laser technology. In the 21st century, new laser spectrometry will be developed, which may be based on revolutionary ideas or unexpected discoveries. Such studies will open new frontiers in analytical laser spectroscopy.

  9. Inertial fusion by laser

    International Nuclear Information System (INIS)

    Dautray, R.; Watteau, J.-P.

    1980-01-01

    Following a brief historical survey of research into the effects of interaction of laser with matter, the principles of fusion by inertial confinement are described and the main parameters and possible levels given. The development of power lasers is then discussed with details of performances of the main lasers used in various laboratories, and with an assessment of the respective merits of neodymium glass, carbon dioxide or iodine lasers. The phenomena of laser radiation and its interaction with matter is then described, with emphasis on the results of experiments concerned with target implosion with the object of compressing and heating the mixture of heavy hydrogen and tritium to be ignited. Finally, a review is made of future possibilities opened up by the use of large power lasers which have recently become operational or are being constructed, and the ground still to be covered before a reactor can be produced [fr

  10. Laser ablation of liquid surface in air induced by laser irradiation through liquid medium

    Science.gov (United States)

    Utsunomiya, Yuji; Kajiwara, Takashi; Nishiyama, Takashi; Nagayama, Kunihito; Kubota, Shiro; Nakahara, Motonao

    2010-10-01

    The pulse laser ablation of a liquid surface in air when induced by laser irradiation through a liquid medium has been experimentally investigated. A supersonic liquid jet is observed at the liquid-air interface. The liquid surface layer is driven by a plasma plume that is produced by laser ablation at the layer, resulting in a liquid jet. This phenomenon occurs only when an Nd:YAG laser pulse (wavelength: 1064 nm) is focused from the liquid onto air at a low fluence of 20 J/cm2. In this case, as Fresnel’s law shows, the incident and reflected electric fields near the liquid surface layer are superposed constructively. In contrast, when the incident laser is focused from air onto the liquid, a liquid jet is produced only at an extremely high fluence, several times larger than that in the former case. The similarities and differences in the liquid jets and atomization processes are studied for several liquid samples, including water, ethanol, and vacuum oil. The laser ablation of the liquid surface is found to depend on the incident laser energy and laser fluence. A pulse laser light source and high-resolution film are required to observe the detailed structure of a liquid jet.

  11. The development of laser fusion research

    Energy Technology Data Exchange (ETDEWEB)

    Mima, Kunioki [Osaka Univ., Suita (Japan). Inst. of Laser Engineering

    1998-11-01

    Laser fusion research started soon after the invention of laser. In 1972, the research was declassified and nuclear fusion by laser inplosion was proposed by J. Nuckolls. Since then, 26 years has passed and laser implosion experiments demonstrated 1000 times solid density compression. By the demonstration of 1000 times solid density, the mission of the laser fusion research shifted from `implosion physics` to `ignition and high gain`, namely demonstration of fusion output of 100 times input laser energy. By the recent developments of laser technology, ultra intense laser became available and opened up a new ignition scheme which is called `Fast Ignition`. The technology for the diode pumped solid state laser (DPSSL) is developed toward a laser driver for reactor. U.S. and France are constructing MJ lasers for demonstrating ignition and burn and Osaka University is investigating the fast ignition and the equivalent plasma of confinement (EPOC) toward high gain. (author)

  12. The development of laser fusion research

    International Nuclear Information System (INIS)

    Mima, Kunioki

    1998-01-01

    Laser fusion research started soon after the invention of laser. In 1972, the research was declassified and nuclear fusion by laser inplosion was proposed by J. Nuckolls. Since then, 26 years has passed and laser implosion experiments demonstrated 1000 times solid density compression. By the demonstration of 1000 times solid density, the mission of the laser fusion research shifted from 'implosion physics' to 'ignition and high gain', namely demonstration of fusion output of 100 times input laser energy. By the recent developments of laser technology, ultra intense laser became available and opened up a new ignition scheme which is called 'Fast Ignition'. The technology for the diode pumped solid state laser (DPSSL) is developed toward a laser driver for reactor. U.S. and France are constructing MJ lasers for demonstrating ignition and burn and Osaka University is investigating the fast ignition and the equivalent plasma of confinement (EPOC) toward high gain. (author)

  13. Thermonuclear fusion plasma produced by lasers

    International Nuclear Information System (INIS)

    Yamanaka, C.; Yokoyama, M.; Nakai, S.; Sasaki, T.; Yoshida, K.; Matoba, M.; Yamabe, C.; Tschudi, T.; Yamanaka, T.; Mizui, J.; Yamaguchi, N.; Nishikawa, K.

    1975-01-01

    Recently, much attention has been focused on laser fusion schemes using high-density plasmas produced by implosion. Scientific-feasibility laser-fusion experiments are now in time. But the physics of interaction between laser and plasma, the high-compression technique and the development of high-power lasers are still important problems to be solved if laser fusion is to make some progress. In the field of laser-plasma coupling, experiments were carried out in which hydrogen and deuterium sticks were bombarded by laser beams; in these experiments, a glass-laser system, LETKKO-I, with an energy of 50 J in a nanosecond pulse, and a double-discharge TEA CO 2 laser system with an energy of 100 J in a 100-ns pulse were used. A decrease in reflectivity occurred at a laser intensity one order of magnitude higher than the parametric-instability threshold. Self-phase modulation of scattered light due to modulational instability was found. A Brillouin-backscattering isotope effect due to the hydrogen and deuterium plasma has also been observed in the red-side part of the SHG-light. Preliminary compression experiments have been carried out using a glass-laser system LETKKO-II, with an energy of 250-1000 J in a ns-pulse. A hologram has been used to study shock waves in the plasma due to the SHG-light converted from the main laser beam. Development of high-power lasers has been promoted, such as disc-glass lasers, E-beam CO 2 lasers and excimer lasers. (author)

  14. Laser Doppler velocimetry based on the optoacoustic effect in a RF-excited CO{sub 2} laser

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Teaghee; Choi, Jong Woon [Department of Information and Communication, Honam University, Seobong-dong 59-1, Gwansan-gu, Gwangju 506-714 (Korea, Republic of); Kim, Yong Pyung [College of Electronics and Information, Kyunghee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of)

    2012-09-15

    We present a compact optoacoustic laser Doppler velocimetry method that utilizes the self-mixing effect in a RF-excited CO{sub 2} laser. A portion of a Doppler-shifted laser beam, produced by irradiating a single wavelength laser beam on a moving object, is mixed with an originally existing laser beam inside a laser cavity. The fine change of pressure in the laser cavity modulated by the Doppler-shifted frequency is detected by a condenser microphone in the laser tube. In our studies, the frequency of the Doppler signal due to the optoacoustic effect was detected as high as 50 kHz. Our measurements also confirmed that the signal varied linearly with the velocity of the external scatterer (the moving object) and the cosine of the angle between the laser beam and the velocity vector of the object.

  15. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    2008-01-01

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., frequency doubling in external cavities, reliable cw-parametric oscillators, tunable narrow-band UV sources, more sensitive detection techniques, tunable femtosecond and sub-femtosecond lasers (X-ray region and the attosecond range), control of atomic and molecular excitations, frequency combs able to synchronize independent femtosecond lasers, coherent matter waves, and still more applications in chemical analysis, medical diagnostics, and engineering.

  16. Selective weed control using laser techniques

    OpenAIRE

    Marx, Christian; Pastrana-Perez, Julio; Hustedt, Michael; Barcikowski, Stephan; Haferkamp, Heinz; Rath, Thomas

    2012-01-01

    This contribution discusses technical and growth relevant aspects of using laser techniques for weed control. The research on thermal weed control via laser first focused on the interaction of laser beams and weed plants. Due to preliminary studies, a CO2-laser was selected for further studies with regard to the process factors laser energy, laser spot area, coverage of the weeds meristem, weed species (Amaranthus retroflexus), and weed growth stage. Thereby, the laser damage was modeled in o...

  17. Induced Current Characteristics Due to Laser Induced Plasma and Its Application to Laser Processing Monitoring

    International Nuclear Information System (INIS)

    Madjid, Syahrun Nur; Idris, Nasrullah; Kurniawan, Koo Hendrik; Kagawa, Kiichiro

    2011-01-01

    In laser processing, suitable conditions for laser and gas play important role in ensuring a high quality of processing. To determine suitable conditions, we employed the electromagnetic phenomena associated with laser plasma generation. An electrode circuit was utilised to detect induced current due to the fast electrons propelled from the material during laser material processing. The characteristics of induced current were examined by changing parameters such as supplied voltage, laser pulse energy, number of laser shots, and type of ambient gas. These characteristics were compared with the optical emission characteristics. It was shown that the induced current technique proposed in this study is much more sensitive than the optical method in monitoring laser processing, that is to determine the precise focusing condition, and to accurately determine the moment of completion of laser beam penetration. In this study it was also shown that the induced current technique induced by CW CO 2 laser can be applied in industrial material processing for monitoring the penetration completion in a stainless steel plate drilling process.

  18. High-energy 4ω probe laser for laser-plasma experiments at Nova

    International Nuclear Information System (INIS)

    Glenzer, S.H.; Weiland, T.L.; Bower, J.; MacKinnon, A.J.; MacGowan, B.J.

    1999-01-01

    For the characterization of inertial confinement fusion plasmas, we implemented a high-energy 4ω probe laser at the Nova laser facility. A total energy of >50 J at 4ω, a focal spot size of order 100 μm, and a pointing accuracy of 100 μm was demonstrated for target shots. This laser provides intensities of up to 3x10 14 Wcm -2 and therefore fulfills high-power requirements for laser-plasma interaction experiments. The 4ω probe laser is now routinely used for Thomson scattering. Successful experiments were performed in gas-filled hohlraums at electron densities of n e >2x10 21 cm -3 which represents the highest density plasma so far being diagnosed with Thomson scattering. copyright 1999 American Institute of Physics

  19. 77 FR 14838 - General Electric-Hitachi Global Laser Enrichment LLC, Commercial Laser-Based Uranium Enrichment...

    Science.gov (United States)

    2012-03-13

    ... Laser Enrichment LLC, Commercial Laser-Based Uranium Enrichment Facility, Wilmington, North Carolina... a license to General Electric-Hitachi Global Laser Enrichment LLC (GLE or the applicant) to authorize construction of a laser-based uranium enrichment facility and possession and use of byproduct...

  20. Realization of double-pulse laser irradiating scheme for laser ion sources

    International Nuclear Information System (INIS)

    Li Zhangmin; Jin Qianyu; Liu Wei; Zhang Junjie; Sha Shan; Zhao Huanyu; Sun Liangting; Zhang Xuezhen; Zhao Hongwei

    2015-01-01

    A double-pulse laser irradiating scheme has been designed and established for the production of highly charged ion beams at Institute of Modern Physics (IMP), Chinese Academy of Sciences. The laser beam output by a Nd : YAG laser is split and combined by a double of beam splitters, between which the split laser beams are transmitted along different optical paths to get certain time delay between each other. With the help of a quarter-wave plate before the first splitter, the energy ratio between the two laser pulses can be adjusted between 3 : 8 to 8 : 3. To testify its feasibility, a preliminary experiment was carried out with the new-developed double-pulse irradiating scheme to produce highly charged carbon ions. Comparing the results with those got from the previous single-pulse irradiating scheme, the differences in the time structure and Charge State Distribution (CSD) of the ion pulse were observed, but its mechanisms and optimization require further studies. (authors)

  1. Powering laser diode systems

    CERN Document Server

    Trestman, Grigoriy A

    2017-01-01

    This Tutorial Text discusses the competent design and skilled use of laser diode drivers (LDDs) and power supplies (PSs) for the electrical components of laser diode systems. It is intended to help power-electronic design engineers during the initial design stages: the choice of the best PS topology, the calculation of parameters and components of the PS circuit, and the computer simulation of the circuit. Readers who use laser diode systems for research, production, and other purposes will also benefit. The book will help readers avoid errors when creating laser systems from ready-made blocks, as well as understand the nature of the "mystical failures" of laser diodes (and possibly prevent them).

  2. Pulsed Laser Centre (CLPU). The Salamanca peta watt laser; Centro de Laseres Pulsados (CLPU). El laser de Petavatio de Salamanca

    Energy Technology Data Exchange (ETDEWEB)

    Franco, L. R.

    2016-08-01

    With pulses lasting 30 photo seconds, the CLPU VEGA laser is capable of generating a peak power level of one peta watt, this making it one of the worlds most powerful lasers. When focussed it can reach extreme intensities. The way in which a pulse of this nature interacts with an atom or what its applications might be are among the questions answered by this article. (Author)

  3. Laser spectroscopy of the products of photoevaporation with a short-wavelength (λ = 193 nm) excimer laser

    International Nuclear Information System (INIS)

    Gochelashvili, K S; Zemskov, M E; Evdokimova, O N; Mikhkel'soo, V T; Prokhorov, A M

    1999-01-01

    An excimer laser spectrometer was designed and constructed. It consists of a high-vacuum interaction chamber, a short-wavelength (λ = 193 nm) excimer ArF laser used for evaporation, a probe dye laser pumped by an XeCl excimer laser, and a system for recording a laser-induced fluorescence signal. This spectrometer was used to investigate nonthermal mechanisms of photoevaporation of a number of wide-gap dielectrics. (laser applications and other topics in quantum electronics)

  4. Laser Protection TIL

    Data.gov (United States)

    Federal Laboratory Consortium — The Laser Protection TIL conducts research and analysis of laser protection materials along with integration schemes. The lab's objectives are to limit energy coming...

  5. Laser welding and collagen crosslinks

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, K.M.; Last, J.A. [California Univ., Davis, CA (United States). Dept. of Medicine; Small, W. IV; Maitland, D.J.; Heredia, N.J.; Da Silva, L.B.; Matthews, D.L. [Lawrence Livermore National Lab., CA (United States)

    1997-02-20

    Strength and stability of laser-welded tissue may be influenced, in part, by effects of laser exposure on collagen crosslinking. We therefore studied effects of diode laser exposure (805 nm, 1-8 watts, 30 seconds) + indocyanine green dye (ICG) on calf tail tendon collagen crosslinks. Effect of ICG dye alone on crosslink content prior to laser exposure was investigated; unexpectedly, we found that ICG-treated tissue had significantly increased DHLNL and OHP, but not HLNL. Laser exposure after ICG application reduced elevated DHLNL and OHP crosslink content down to their native levels. The monohydroxylated crosslink HLNL was inversely correlated with laser output (p<0.01 by linear regression analysis). DHLNL content was highly correlated with content of its maturational product, OHP, suggesting that precursor-product relations are maintained. We conclude that: (1)ICG alone induces DHLNL and OHP crosslink formation; (2)subsequent laser exposure reduces the ICG-induced crosslinks down to native levels; (3)excessive diode laser exposure destroys normally occurring HLNL crosslinks.

  6. Wavefront Measurement for Laser-Guiding Diagnostic

    International Nuclear Information System (INIS)

    Shiraishi, S.; Gonsalves, A.J.; Lin, C.; Nakamura, K.; Osterhoff, J.; Sokollik, T.; van Tilborg, J.; Geddes, C.G.R.; Schroeder, C.B.; Toth, Cs.; Esarey, E.; Leemans, W.P.

    2010-01-01

    The wavefront of a short laser pulse after interaction in a laser-plasma accelerator (LPA) was measured to diagnose laser-guiding quality. Experiments were performed on a 100 TW class laser at the LOASIS facility of LBNL using a hydrogenfilled capillary discharge waveguide. Laser-guiding with a pre-formed plasma channel allows the laser pulse to propagate over many Rayleigh lengths at high intensity and is crucial to accelerate electrons to the highest possible energy. Efficient coupling of laser energy into the plasma is realized when the laser and the channel satisfy a matched guiding condition, in which the wavefront remains flat within the channel. Using a wavefront sensor, the laser-guiding quality was diagnosed based on the wavefront of the laser pulse exiting the plasma channel. This wavefront diagnostic will contribute to achieving controlled, matched guiding in future experiments.

  7. Laser therapy of muscle injuries.

    Science.gov (United States)

    Dawood, Munqith S; Al-Salihi, Anam Rasheed; Qasim, Amenah Wala'a

    2013-05-01

    Low-level lasers are used in general therapy and healing process due to their good photo-bio-stimulation effects. In this paper, the effects of diode laser and Nd:YAG laser on the healing process of practically managed skeletal muscle trauma has been successfully studied. Standard impact trauma was induced by using a specially designed mechanical device. The impacted muscle was left for 3 days for complete development of blunt trauma. After that it was irradiated by five laser sessions for 5 days. Two types of lasers were used; 785-nm diode laser and 1.064-nm Nd:YAG laser, both in continuous and pulsed modes. A special electronic circuit was designed and implemented to modulate the diode laser for this purpose. Tissue samples of crushed skeletal muscle have been dissected from the injured irradiated muscle then bio-chemically analyzed for the regeneration of contractile and collagenous proteins using Lowry assay for protein determination and Reddy and Enwemeka assay for hydroxyproline determination. The results showed that both lasers stimulate the regeneration capability of traumatized skeletal muscle. The diode laser in CW and pulsed modes showed better results than the Nd:YAG in accelerating the preservation of the normal tissue content of collagenous and contractile proteins beside controlling the regeneration of non-functional fibrous tissue. This study proved that the healing achieved by the laser treatment was faster than the control group by 15-20 days.

  8. Laser modulator for LISA pathfinder

    Science.gov (United States)

    Voland, C.; Lund, G.; Coppoolse, W.; Crosby, P.; Stadler, M.; Kudielka, K.; Özkan, C.

    2017-11-01

    LISA Pathfinder is an ESA experiment to demonstrate the key technologies needed for the LISA mission to detect gravitational waves in space. The LISA Pathfinder spacecraft represents one arm of the LISA interferometer, containing an optical metrology system and two proof masses as inertial references for the drag-free control system. The LISA Pathfinder payload consists of two drag-free floating test masses located in the inertial sensors with their control electronics and an optical metrology subsystem. The optical metrology subsystem monitors the movement of both test masses relative to each other and to the spacecraft with very high sensitivity and resolution. This is achieved with a heterodyne Mach- Zehnder interferometer. This interferometer requires as input two coherent laser beams with a heterodyne frequency difference of a few kHz. To generate the two laser beams with a heterodyne frequency difference a Nd:YAG laser is used together with the Laser Modulator. The Nd:YAG laser generates a single coherent laser signal at a wavelength of 1064nm which is fibre coupled to the Laser Modulator. The Laser Modulator then generates the two optical beams with the required heterodyne frequency offset. In addition, the Laser Modulator is required to perform laser amplitude stabilization and optical path difference control for the two optical signals. The Laser Modulator consists of an optical unit - the LMU - and RF synthesiser, power amplification and control electronics. These electronics are all housed in the Laser Modulator Electronics (LME). The LMU has four primary functions: • Splitting of the input laser beam into two paths for later superposition in the interferometer. • Applying different frequency shifts to each of the beams. • Providing amplitude modulation control to each of the beams. • Providing active control of the optical path length difference between the two optical paths. The present paper describes the design and performance of the LMU

  9. Improvement of a triple-wavelength erbium-doped fiber laser using a Fabry–Perot laser diode

    International Nuclear Information System (INIS)

    Peng, P C; Hu, H L; Wang, J B

    2013-01-01

    This work demonstrates the feasibility of a simple construct of a tunable triple-wavelength fiber ring laser using a Fabry–Perot laser diode (FP-LD) and an optical tunable bandpass filter. An optical tunable bandpass filter is used within the cavity of an erbium-doped fiber laser to select the lasing wavelength. Because the Fabry–Perot laser diode is in combination with the tunable bandpass filter, the erbium-doped fiber laser can stably lase three wavelengths simultaneously. Moreover, this laser is easily tuned dynamically. This triple-wavelength output performs satisfactorily, with its optical side-mode-suppression-ratio (SMSR) exceeding 40 dB. Furthermore, the wavelength tuning range of this triple-wavelength erbium-doped fiber laser is greater than 27 nm. (paper)

  10. Polarization methods for diode laser excitation of solid state lasers

    Science.gov (United States)

    Holtom, Gary R.

    2008-11-25

    A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. A Yb-doped gain medium can be used that absorbs light having a first polarization and emits light having a second polarization. Using such pumping with laser cavity dispersion control, pulse durations of less than 100 fs can be achieved.

  11. Interactions between laser and arc plasma during laser-arc hybrid welding of magnesium alloy

    Science.gov (United States)

    Liu, Liming; Chen, Minghua

    2011-09-01

    This paper presents the results of the investigation on the interactions between laser and arc plasma during laser-arc hybrid welding on magnesium alloy AZ31B using the spectral diagnose technique. By comparably analyzing the variation in plasma information (the shape, the electron temperature and density) of single tungsten inert gas (TIG) welding with the laser-arc hybrid welding, it is found that the laser affects the arc plasma through the keyhole forming on the workpiece. Depending on the welding parameters there are three kinds of interactions taking place between laser and arc plasma.

  12. The influence of laser pulse waveform on laser-TIG hybrid welding of AZ31B magnesium alloy

    Science.gov (United States)

    Song, Gang; Luo, Zhimin

    2011-01-01

    By dividing laser pulse duration into two parts, three kinds of laser waveforms are designed, including a high power density pulse (HPDP) laser in a short duration set at the beginning of the laser waveform. This paper aims to find out the laser pulse waveform and idiographic critical values of HPDP, which can affect the magnesium penetration in laser-tungsten inert gas (TIG) hybrid welding. Results show that when the laser pulse duration of HPDP is not more than 0.4 ms, the welding penetration values of lasers with HPDP are larger than otherwise. Also, the welding penetration values of laser with HPDP have increased by up to 26.1%. It has been found that with HPDP, the laser can form the keyhole more easily because the interaction between laser and the plate is changed, when the TIG arc preheats the plate. Besides, the laser with high power density and short duration strikes on the plates so heavily that the corresponding background power can penetrate into the bottom of the keyhole and maintain the keyhole open, which facilitates the final welding penetration.

  13. Histologic effects of resurfacing lasers.

    Science.gov (United States)

    Freedman, Joshua R; Greene, Ryan M; Green, Jeremy B

    2014-02-01

    By utilizing resurfacing lasers, physicians can significantly improve the appearance of sun-damaged skin, scars, and more. The carbon dioxide and erbium:yttrium-aluminum-garnet lasers were the first ablative resurfacing lasers to offer impressive results although these earlier treatments were associated with significant downtime. Later, nonablative resurfacing lasers such as the neodymium:yttrium-aluminum-garnet laser proved effective, after a series of treatments with less downtime, but with more modest results. The theory of fractional photothermolysis has revolutionized resurfacing laser technology by increasing the safety profile of the devices while delivering clinical efficacy. A review of the histologic and molecular consequences of the resurfacing laser-tissue interaction allows for a better understanding of the devices and their clinical effects. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. The high-power iodine laser

    Science.gov (United States)

    Brederlow, G.; Fill, E.; Witte, K. J.

    The book provides a description of the present state of the art concerning the iodine laser, giving particular attention to the design and operation of pulsed high-power iodine lasers. The basic features of the laser are examined, taking into account aspects of spontaneous emission lifetime, hyperfine structure, line broadening and line shifts, stimulated emission cross sections, the influence of magnetic fields, sublevel relaxation, the photodissociation of alkyl iodides, flashlamp technology, excitation in a direct discharge, chemical excitation, and questions regarding the chemical kinetics of the photodissociation iodine laser. The principles of high-power operation are considered along with aspects of beam quality and losses, the design and layout of an iodine laser system, the scalability and prospects of the iodine laser, and the design of the single-beam Asterix III laser.

  15. Direct laser writing for nanoporous liquid core laser sensors

    DEFF Research Database (Denmark)

    Grossmann, Tobias; Christiansen, Mads Brøkner; Peterson, Jeffrey

    2012-01-01

    We report the fabrication of nanoporous liquid core lasers via direct laser writing based on two-photon absorption in combination with thiolene-chemistry. As gain medium Rhodamine 6G was embedded in the nanoporous polybutadiene matrix. The lasing devices with thresholds of 19 µJ/mm2 were measured...

  16. Improvement of laser irradiation uniformity in GEKKO XII glass laser system

    International Nuclear Information System (INIS)

    Miyanaga, Noriaki; Matsuoka, Shinichi; Ando, Akinobu; Amano, Shinji; Nakatsuka, Masahiro; Kanabe, Tadashi; Jitsuno, Takahisa; Nakai, Sadao

    1995-01-01

    The uniform laser irradiation is one of key issues in the direct drive laser fusion research. The several key technologies for the uniform laser irradiation are reported. This paper includes the uniformity performance as a result of the introduction of the random phase plate, the partially coherent light and the beam smoothing by spectral dispersion into the New Gekko XI glass laser system. Finally the authors summarize the overall irradiation uniformity on the spherical target surface by considering the power imbalance effect. The technologies developed for the beam smoothing and the power balance control enable them to achieve the irradiation nonuniformities of around 1% level for a foot pulse and of a few % for a main drive pulse, respectively

  17. Laser in operative dentistry

    OpenAIRE

    E. Yasini; Gh. Rahbari; A. Matorian

    1994-01-01

    Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy) and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry), etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks...

  18. Status of Nuclear-Pumped Laser research

    International Nuclear Information System (INIS)

    Prelas, M.A.

    1984-01-01

    The field of Nuclear-Pumped lasers (NPLs) has progressed in many directions since the discovery of the first NPL in 1974. This paper discusses developments in the area of coupling nuclear energy to a laser media, kinetics, and the integration of nuclear reactors to a laser (or other types of energy conversion medium). Many questions about the process of nuclear-pumping have been examined since the discovery of the first NPL in 1974. During a period of time between 1974 and 1981, several types of lasers have been driven by nuclear reactions (ie rare gas lasers, impurity type lasers, molecular lasers, and an ion laser). Three of the lasers discovered, had demonstrated efficiencies of >1%. In addition, volume scaling of NPLs was demonstrated

  19. A Guide to Laser Safety

    Energy Technology Data Exchange (ETDEWEB)

    Davies, W M

    1998-09-01

    In one of the few volumes dedicated to laser safety to appear since the 'bible' of Sliney and Wolbarsht, Roy Henderson sets out to provide the reader with a practical account of both the philosophy and practice across contemporary application of lasers. The book is split into three sections. The first section is essentially a non-mathematical review of lasers, optical hazards and laser safety. It is intended as an easily digestible introduction to the subject, conveying the primary concepts of laser safety without the camouflage of equations. This piece of text is manifestly readable by all who have interest in the topic. The second section introduces more meat onto the bones introduced in the first section and some of the practical mathematics necessary to determine optical irradiance in simple laser beams. The book is not intended as a scientific treatise and rigorous treatment of laser physics is left (for the better) to other texts. Laser hazard assessment and safety management are covered in sufficient detail to allow the reader to understand what precautions are necessary to mitigate the risks of laser use. The final section takes a brief look at laser safety in a number of specific industrial applications. These include industrial processing, medicine, telecommunications and entertainment. These should be taken in the context of the second section and are not stand-alone text. With few typographical errors, and packed with practical hints, this book serves as an excellent text for any educational course on laser safety and provides a quick and easy reference for laser safety officers. (book review: A Roy Henderson - ISBN: 0 412 72940 7)

  20. Eye safe laser range finders

    International Nuclear Information System (INIS)

    Snir, M.; Margaliot, M.; Amitzi, A.

    2004-01-01

    During the 1970's, Ruby (Q switched) laser based range finders with a wavelength of 694nm were first used. These lasers operated in a pulse mode within the visible light range and produced a risk for the eye retina. The laser beam striking the macula could damage the eye and might cause blindness. Over the years, Nd:YAG (Q switched) lasers were developed (operating at 1064nm) for range finding and designation uses. The wavelength of these lasers, operating in the near Infra-Red range (invisible), is also focused tightly on the retina. The human eye does not respond to the invisible light so there is no natural protection (eye blink reflex) as in the visible light. The operation of these lasers worldwide, especially when the laser beam is exposed, causes occasional eye accidents. Another risk is stemming from the use of observation systems with a high optical gain, in the laser operation areas, which enlarge the range of risk quite significantly. Therefore, research and development efforts were invested in order to introduce eye safe lasers. One of the solutions for this problem is presented in following document

  1. Laser-plasma accelerators, acceleration of particles through laser-matter interaction at ultra-high intensity

    International Nuclear Information System (INIS)

    Lefebvre, E.

    2010-01-01

    This series of slides overviews the development of powerful lasers for inertial confinement fusion (Icf) at NIF (National Ignition Facility, Usa) and LMJ (Laser Megajoule, France) facilities. Then the principle of laser wakefield acceleration is presented and the possibility of designing compact accelerators delivering 200 GeV/m while conventional RF accelerators reach only 50 MeV/m, is considered. This technical breakthrough will bring important gains in terms of size, cost and new uses for accelerators. While Icf will use nanosecond (10 -9 s) laser pulses, wakefield accelerators will use femtosecond (10 -15 s) laser pulses which means more power but less energy. The electrons accelerated by laser can produce a multi-MeV X radiation useful for industrial radiography or cancer treatment. (A.C.)

  2. Target isolation system, high power laser and laser peening method and system using same

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd A.; Harris, Fritz

    2007-11-06

    A system for applying a laser beam to work pieces, includes a laser system producing a high power output beam. Target delivery optics are arranged to deliver the output beam to a target work piece. A relay telescope having a telescope focal point is placed in the beam path between the laser system and the target delivery optics. The relay telescope relays an image between an image location near the output of the laser system and an image location near the target delivery optics. A baffle is placed at the telescope focal point between the target delivery optics and the laser system to block reflections from the target in the target delivery optics from returning to the laser system and causing damage.

  3. Numerical analysis of laser ablation and damage in glass with multiple picosecond laser pulses.

    Science.gov (United States)

    Sun, Mingying; Eppelt, Urs; Russ, Simone; Hartmann, Claudia; Siebert, Christof; Zhu, Jianqiang; Schulz, Wolfgang

    2013-04-08

    This study presents a novel numerical model for laser ablation and laser damage in glass including beam propagation and nonlinear absorption of multiple incident ultrashort laser pulses. The laser ablation and damage in the glass cutting process with a picosecond pulsed laser was studied. The numerical results were in good agreement with our experimental observations, thereby revealing the damage mechanism induced by laser ablation. Beam propagation effects such as interference, diffraction and refraction, play a major role in the evolution of the crater structure and the damage region. There are three different damage regions, a thin layer and two different kinds of spikes. Moreover, the electronic damage mechanism was verified and distinguished from heat modification using the experimental results with different pulse spatial overlaps.

  4. Efficient second harmonics generation of a laser-diode-pumped Nd:YAG laser and its applications. Laser diode reiki Nd:YAG laser no kokoritsu daini kochoha hassei to sono oyo

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, S.; Oka, M. (Sony Corp., Tokyo (Japan))

    1991-08-10

    Stabilization of the second harmonics in a laser-diode-pumped Nd:YAG laser and its application are described. The laser is a quantum noise limiting laser, in which a mode competing noise is generated from an interaction between the laser medium Nd:YAG and the type II nonlinear optical crystal KTiOPO{sub 4} when generating a second harmonics in the resonator. However, the quantum noise limiting second harmonics was obtained by means of inserting (1/4) wave length plate in the resonator to release the bond between two intersecting inherent polarization modes. This stabilized green laser is of a single lateral mode is nearly free of aberration. Therefore, an optical disc prototype having three times as much of the currently used density was made using an objective lens having high number of openings to collect lights, which was verified capable of regeneration at a high signal to noise ratio. In addition, higher output is possible by means of parallelizing the excitation, and high output is realized from edge excitation at a fiber bundle. 18 refs., 3 figs.

  5. Lasers for isotope separation

    International Nuclear Information System (INIS)

    O'Hair, E.A.; Piltch, M.S.

    1976-01-01

    The Los Alamos Scientific Laboratory is conducting research on uranium enrichment. All processes being studied employ uranium molecules and use lasers to provide isotopic selectivity and enrichment. There are four well-defined infrared frequencies and two ultraviolet frequency bands of interest. The infrared frequencies are outside the range of the available lasers and an extensive research and development activity is currently underway. Lasers are available in the uv bands, however, much development work remains. The specification for the commercial uranium enrichment plant lasers will depend upon the results of the current enrichment experiments, the laser capital cost, reliability, and maintenance cost. For the processes under investigation there are specific photon requirements but latitude in how these requirements can be met. The final laser selections for the pilot plant need not be made until the mid-1980's. Between now and that time as extensive as possible a research and development effort will be maintained

  6. Power Laser Ablation Symposia

    CERN Document Server

    Phipps, Claude

    2007-01-01

    Laser ablation describes the interaction of intense optical fields with matter, in which atoms are selectively driven off by thermal or nonthermal mechanisms. The field of laser ablation physics is advancing so rapidly that its principal results are seen only in specialized journals and conferences. This is the first book that combines the most recent results in this rapidly advancing field with authoritative treatment of laser ablation and its applications, including the physics of high-power laser-matter interaction. Many practical applications exist, ranging from inertial confinement fusion to propulsion of aerostats for pollution monitoring to laser ignition of hypersonic engines to laser cleaning nanoscale contaminants in high-volume computer hard drive manufacture to direct observation of the electronic or dissociative states in atoms and molecules, to studying the properties of materials during 200kbar shocks developed in 200fs. Selecting topics which are representative of such a broad field is difficu...

  7. Laser machining micro-structures on diamond surface with a sub-nanosecond pulsed laser

    Science.gov (United States)

    Wu, Mingtao; Guo, Bing; Zhao, Qingliang

    2018-02-01

    Micro-structure surface on diamond material is widely used in a series of industrial and scientific applications, such as micro-electromechanical systems (MEMS), nanoelectromechanical systems (NEMS), microelectronics, textured or micro-structured diamond machining tools. The efficient machining of micro-structure on diamond surface is urgently demanded in engineering. In this paper, laser machining square micro-structure on diamond surface was studied with a sub-nanosecond pulsed laser. The influences of laser machining parameters, including the laser power, scanning speed, defocusing quantity and scanning pitch, were researched in view of the ablation depth, material removal rate and machined surface topography. Both the ablation depth and material removal rate increased with average laser power. A reduction of the growth rate of the two parameters was induced by the absorption of the laser plasma plume at high laser power. The ablation depth non-linearly decreased with the increasing of the scanning speed while the material removal rate showed an opposite tendency. The increasing of the defocusing quantity induced complex variation of the ablation depth and the material removal rate. The maximum ablation depth and material removal rate were achieved at a defocusing position. The ablation depth and material removal rate oppositely varied about the scanning pitch. A high overlap ratio was meaningful for achieving a smooth micro-structure surface topography. Laser machining with a large defocusing quantity, high laser power and small scanning pitch was helpful for acquiring the desired micro-structure which had a large depth and smooth micro-structure surface topography.

  8. Characteristics of a laser beam produced by using thermal lensing effect compensation in a fiber-coupled laser-diode-pumped Nd:YAG ceramic laser

    International Nuclear Information System (INIS)

    Kim, Duck-Lae; Kim, Byung-Tai

    2010-01-01

    The characteristics of a laser beam produced by using thermal lensing effect compensation in a fiber-coupled laser-diode Nd:YAG ceramic laser were investigated. The thermal lensing effect was compensated for by using a compensator, which was 25 mm away from the laser rod, with a focal length of 30 mm and an effective clear aperture of 22 mm. Using a compensator, the divergence and the beam propagation factor M 2 of the output beam were 5.5 mrad and 2.4, respectively, under a pump power of 12W. The high-frequency components in the compensated laser beam were removed.

  9. Diode Lasers used in Plastic Welding and Selective Laser Soldering - Applications and Products

    Science.gov (United States)

    Reinl, S.

    Aside from conventional welding methods, laser welding of plastics has established itself as a proven bonding method. The component-conserving and clean process offers numerous advantages and enables welding of sensitive assemblies in automotive, electronic, medical, human care, food packaging and consumer electronics markets. Diode lasers are established since years within plastic welding applications. Also, soft soldering using laser radiation is becoming more and more significant in the field of direct diode laser applications. Fast power controllability combined with a contactless temperature measurement to minimize thermal damage make the diode laser an ideal tool for this application. These advantages come in to full effect when soldering of increasingly small parts in temperature sensitive environments is necessary.

  10. Effect of laser pulse energies in laser induced breakdown spectroscopy in double-pulse configuration

    International Nuclear Information System (INIS)

    Benedetti, P.A.; Cristoforetti, G.; Legnaioli, S.; Palleschi, V.; Pardini, L.; Salvetti, A.; Tognoni, E.

    2005-01-01

    In this paper, the effect of laser pulse energy on double-pulse laser induced breakdown spectroscopy signal is studied. In particular, the energy of the first pulse has been changed, while the second pulse energy is held fixed. A systematic study of the laser induced breakdown spectroscopy signal dependence on the interpulse delay is performed, and the results are compared with the ones obtained with a single laser pulse of energy corresponding to the sum of the two pulses. At the same time, the crater formed at the target surface is studied by video-confocal microscopy, and the variation in crater dimensions is correlated to the enhancement of the laser induced breakdown spectroscopy signal. The results obtained are consistent with the interpretation of the double-pulse laser induced breakdown spectroscopy signal enhancement in terms of the changes in ambient gas pressure produced by the shock wave induced by the first laser pulse

  11. Dependence of laser assisted cleaning of clad surfaces on the laser fluence

    International Nuclear Information System (INIS)

    Nilaya, J.P.; Raote, P.; Sai Prasad, M.B.; Biswas, D.J.; Aniruddha Kumar

    2005-01-01

    The decontamination factor is studied as a function of laser fluence for three kinds of clad surfaces viz., plain zircaloy, autoclaved zircaloy and SS with cesium as the test contamination. It has been found that the decontamination factor exhibits a maximal behaviour with the laser fluence and its maximum value occurs at different laser fluences in the three cases. The maximal behaviour is attributed to reduced coupling of energy from the laser beam to the substrate due to the initiation of surface-assisted optical breakdown. The results obtained in the experiment carried out in helium environment qualitatively support this explanation (author)

  12. Pattern Laser Annealing by a Pulsed Laser

    Science.gov (United States)

    Komiya, Yoshio; Hoh, Koichiro; Murakami, Koichi; Takahashi, Tetsuo; Tarui, Yasuo

    1981-10-01

    Preliminary experiments with contact-type pattern laser annealing were made for local polycrystallization of a-Si, local evaporation of a-Si and local formation of Ni-Si alloy. These experiments showed that the mask patterns can be replicated as annealed regions with a resolution of a few microns on substrates. To overcome shortcomings due to the contact type pattern annealing, a projection type reduction pattern laser annealing system is proposed for resistless low temperature pattern forming processes.

  13. High resolution laser micro sintering / melting using q-switched and high brilliant laser radiation

    Science.gov (United States)

    Exner, H.; Streek, A.

    2015-03-01

    Since the discovery of selective laser sintering/melting, numerous modifications have been made to upgrade or customize this technology for industrial purposes. Laser micro sintering (LMS) is one of those modifications: Powders with particles in the range of a few micrometers are used to obtain products with highly resolved structures. Pulses of a q-switched laser had been considered necessary in order to generate sinter layers from the micrometer scaled metal powders. LMS has been applied with powders from metals as well as from ceramic and cermet feedstock's to generate micro parts. Recent technological progress and the application of high brilliant continuous laser radiation have now allowed an efficient laser sintering/melting of micrometer scaled metal powders. Thereby it is remarkable that thin sinter layers are generated using high continuous laser power. The principles of the process, the state of the art in LMS concerning its advantages and limitations and furthermore the latest results of the recent development of this technology will be presented. Laser Micro Sintering / Laser Micro Melting (LMM) offer a vision for a new dimension of additive fabrication of miniature and precise parts also with application potential in all engineering fields.

  14. Comparison of laser-based mitigation of fused silica surface damage using mid- versus far-infrared lasers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S T; Matthews, M J; Elhadj, S; Cooke, D; Guss, G M; Draggoo, V G; Wegner, P J

    2009-12-16

    Laser induced growth of optical damage can limit component lifetime and therefore operating costs of large-aperture fusion-class laser systems. While far-infrared (IR) lasers have been used previously to treat laser damage on fused silica optics and render it benign, little is known about the effectiveness of less-absorbing mid-IR lasers for this purpose. In this study, they quantitatively compare the effectiveness and efficiency of mid-IR (4.6 {micro}m) versus far-IR (10.6 {micro}m) lasers in mitigating damage growth on fused silica surfaces. The non-linear volumetric heating due to mid-IR laser absorption is analyzed by solving the heat equation numerically, taking into account the temperature-dependent absorption coefficient {alpha}(T) at {lambda} = 4.6 {micro}m, while far-IR laser heating is well-described by a linear analytic approximation to the laser-driven temperature rise. In both cases, the predicted results agree well with surface temperature measurements based on infrared radiometry, as well as sub-surface fictive temperature measurements based on confocal Raman microscopy. Damage mitigation efficiency is assessed using a figure of merit (FOM) relating the crack healing depth to laser power required, under minimally-ablative conditions. Based on their FOM, they show that for cracks up to at least 500 {micro}m in depth, mitigation with a 4.6 {micro}m mid-IR laser is more efficient than mitigation with a 10.6 {micro}m far-IR laser. This conclusion is corroborated by direct application of each laser system to the mitigation of pulsed laser-induced damage possessing fractures up to 225 {micro}m in depth.

  15. The use of lasers in manufacturing

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    This book contains the proceedings of a conference on the use of lasers in manufacturing, topics covered include: An introduction to industrial lasers; Production laser hardening for aerospace; The role of fiber optics in laser material processing; and Light-material interactions in laser material processing

  16. Laser Hazards Bibliography

    Science.gov (United States)

    1989-10-31

    light on mandibular fracture healing, Stomatologiia, 57(5): 5-9 (1978). 42 Laser Hazards Bibliography 177. Van Gemert, M.J.C., Schets, G.A.C.M., Bishop...U., Laser-coagulation of ruptured fixation suture after lens implantation, J Am Intraocul Implant Soc, 4(2): 54 (1978). 49. Federman, J. L., Ando, F...laser in pediatric surgery, J Ped Surg, 3: 263-270 (April 1968). 82. Hennessy, R. T., and Leibowitz, H., Subjective measurement of accommodation with

  17. Laser precision microfabrication

    CERN Document Server

    Sugioka, Koji; Pique, Alberto

    2010-01-01

    Miniaturization and high precision are rapidly becoming a requirement for many industrial processes and products. As a result, there is greater interest in the use of laser microfabrication technology to achieve these goals. This book composed of 16 chapters covers all the topics of laser precision processing from fundamental aspects to industrial applications to both inorganic and biological materials. It reviews the sate of the art of research and technological development in the area of laser processing.

  18. Advanced metaheuristic algorithms for laser optimization

    International Nuclear Information System (INIS)

    Tomizawa, H.

    2010-01-01

    A laser is one of the most important experimental tools. In synchrotron radiation field, lasers are widely used for experiments with Pump-Probe techniques. Especially for Xray-FELs, a laser has important roles as a seed light source or photo-cathode-illuminating light source to generate a high brightness electron bunch. The controls of laser pulse characteristics are required for many kinds of experiments. However, the laser should be tuned and customized for each requirement by laser experts. The automatic tuning of laser is required to realize with some sophisticated algorithms. The metaheuristic algorithm is one of the useful candidates to find one of the best solutions as acceptable as possible. The metaheuristic laser tuning system is expected to save our human resources and time for the laser preparations. I have shown successful results on a metaheuristic algorithm based on a genetic algorithm to optimize spatial (transverse) laser profiles and a hill climbing method extended with a fuzzy set theory to choose one of the best laser alignments automatically for each experimental requirement. (author)

  19. Laser beam-forming by deformable mirror for laser isotope separation

    International Nuclear Information System (INIS)

    Nemoto, Koshichi; Fujii, Takashi; Goto, Naohiko

    1995-01-01

    A rectangular laser beam of uniform intensity is very suitable for laser isotope separation. In this paper, we propose a beam-forming system which consists two deformable mirrors. One of the mirrors changes the beam intensity and the other compensates for phase distortion. We developed a deformable mirror for beam-forming. Its deformed surface is similar to the ideal mirror surface for beam-forming. We reshaped a Gaussian-like He-Ne laser beam into a beam with a more uniform intensity profile by a simple deformable mirror. (author)

  20. Laser spectroscopy: Assessment of research needs for laser technologies applied to advanced spectroscopic methods

    International Nuclear Information System (INIS)

    Hurst, G.S.

    1990-05-01

    This report is organized as follows. Section 2 summarizes the current program of DOE's Office of Health and Environmental Research (OHER) and provides some remarks on low laser science and technology could beneficially impact most of the research programs. Section 3 provides a brief global perspective on laser technology and attempts to define important trends in the field. Similarly, Section 4 provides a global perspective on laser spectroscopy and addresses important trends. Thus, Section 5 focuses on the trends in laser technology and spectroscopy which could impact the OHER mission in significant ways and contains the basis for recommendations made in the executive summary. For those with limited familiarity with laser technology and laser spectroscopy, reference is made to Appendix 1 for a list of abbreviations and acronyms. Appendix 2 can serve a useful review or tutorial for those who are not deeply involved with laser spectroscopy. Even those familiar with laser spectroscopy and laser technology may find it useful to know precisely what the authors of this document mean by certain specialized terms and expressions. Finally, a note on the style of referencing may be appropriate. Whenever possible a book or review articles is referenced as the preferred citation. However, we frequently found it useful to reference a number of individual papers of recent origin or those which were not conveniently found in the review articles

  1. High power visible diode laser for the treatment of eye diseases by laser coagulation

    Science.gov (United States)

    Heinrich, Arne; Hagen, Clemens; Harlander, Maximilian; Nussbaumer, Bernhard

    2015-03-01

    We present a high power visible diode laser enabling a low-cost treatment of eye diseases by laser coagulation, including the two leading causes of blindness worldwide (diabetic retinopathy, age-related macular degeneration) as well as retinopathy of prematurely born children, intraocular tumors and retinal detachment. Laser coagulation requires the exposure of the eye to visible laser light and relies on the high absorption of the retina. The need for treatment is constantly increasing, due to the demographic trend, the increasing average life expectancy and medical care demand in developing countries. The World Health Organization reacts to this demand with global programs like the VISION 2020 "The right to sight" and the following Universal Eye Health within their Global Action Plan (2014-2019). One major point is to motivate companies and research institutes to make eye treatment cheaper and easily accessible. Therefore it becomes capital providing the ophthalmology market with cost competitive, simple and reliable technologies. Our laser is based on the direct second harmonic generation of the light emitted from a tapered laser diode and has already shown reliable optical performance. All components are produced in wafer scale processes and the resulting strong economy of scale results in a price competitive laser. In a broader perspective the technology behind our laser has a huge potential in non-medical applications like welding, cutting, marking and finally laser-illuminated projection.

  2. Principles of laser dynamics

    CERN Document Server

    Khanin, YI

    1995-01-01

    This monograph summarizes major achievements in laser dynamics over the past three decades. The book begins with two introductory Chapters. Chapter 1 offers general considerations on quantum oscillators, formulates the requirements for the laser key elements and shows how these requirements are met in different laser systems. The second Chapter proposes the mathematical models used in semiclassical laser theory, discusses the approximations and simplifications in particular cases, and specifies the range of applicability of these models. In Chapters 3-5 attention is given primarily to the stea

  3. High Power Vanadate lasers

    CSIR Research Space (South Africa)

    Strauss

    2006-07-01

    Full Text Available stream_source_info Strauss1_2006.pdf.txt stream_content_type text/plain stream_size 3151 Content-Encoding UTF-8 stream_name Strauss1_2006.pdf.txt Content-Type text/plain; charset=UTF-8 Laser Research Institute... University of Stellenbosch www.laser-research.co.za High Power Vanadate lasers H.J.Strauss, Dr. C. Bollig, R.C. Botha, Prof. H.M. von Bergmann, Dr. J.P. Burger Aims 1) To develop new techniques to mount laser crystals, 2) compare the lasing properties...

  4. Laser diode technology and applications

    International Nuclear Information System (INIS)

    Figueroa, L.

    1989-01-01

    This book covers a wide range of semiconductor laser technology, from new laser structures and laser design to applications in communications, remote sensing, and optoelectronics. The authors report on new laser diode physics and applications and present a survey of the state of the art as well as progress in new developments

  5. Laser tests of silicon detectors

    International Nuclear Information System (INIS)

    Dolezal, Zdenek; Escobar, Carlos; Gadomski, Szymon; Garcia, Carmen; Gonzalez, Sergio; Kodys, Peter; Kubik, Petr; Lacasta, Carlos; Marti, Salvador; Mitsou, Vasiliki A.; Moorhead, Gareth F.; Phillips, Peter W.; Reznicek, Pavel; Slavik, Radan

    2007-01-01

    This paper collects experiences from the development of a silicon sensor laser testing setup and from tests of silicon strip modules (ATLAS End-cap SCT), pixel modules (DEPFET) and large-area diodes using semiconductor lasers. Lasers of 1060 and 680 nm wavelengths were used. A sophisticated method of focusing the laser was developed. Timing and interstrip properties of modules were measured. Analysis of optical effects involved and detailed discussion about the usability of laser testing for particle detectors are presented

  6. Laser corrective surgery with fractional carbon dioxide laser following full-thickness skin grafts

    OpenAIRE

    Emily Forbat; Faisal R Ali; Raj Mallipeddi; Firas Al-Niaimi

    2017-01-01

    Full-thickness skin grafts (FTSGs) are frequently used to treat patients with burn injuries and to repair defects rendered by excisional (including Mohs) surgery. The evidence for corrective laser surgery after scar formation is well established. With regard to laser treatment of FTSG, the evidence is sparse. Laser treatment after FTSG is a novel concept, with minimal literature. We present a case series, one of the first to our knowledge, of the treatment of FTSG with fractional CO2 laser in...

  7. Higher coherent x-ray laser

    International Nuclear Information System (INIS)

    Hasegawa, Noboru; Nagashima, Keisuke; Kawachi, Tetsuya

    2001-01-01

    X-ray lasers generated by an ultra short pulse laser have advantages such as monochromatic, short pulse duration, small beam divergence, high intensity, and coherence. Spatial coherence is most important for applications, we have investigated the transient collisional excitation (TCE) scheme x-ray laser lasing from Ne-like titanium (31.6 nm), Ne-like silver (13.9 nm) and tin (11.9 nm). However, the spatial coherence was not so good with this scheme. We have been studying to improve the spatial coherence of the x-ray laser and have proposed to use coherent seed light tuned to the x-ray laser wavelength generated from higher harmonics generation (HHG), which is introduced to the x-ray laser medium (Ne-like titanium, Ni-like silver plasmas). We present about the theoretical study of the coupling efficiency HHG light with x-ray laser medium. (author)

  8. Infrared laser damage thresholds in corneal tissue phantoms using femtosecond laser pulses

    Science.gov (United States)

    Boretsky, Adam R.; Clary, Joseph E.; Noojin, Gary D.; Rockwell, Benjamin A.

    2018-02-01

    Ultrafast lasers have become a fixture in many biomedical, industrial, telecommunications, and defense applications in recent years. These sources are capable of generating extremely high peak power that can cause laser-induced tissue breakdown through the formation of a plasma upon exposure. Despite the increasing prevalence of such lasers, current safety standards (ANSI Z136.1-2014) do not include maximum permissible exposure (MPE) values for the cornea with pulse durations less than one nanosecond. This study was designed to measure damage thresholds in corneal tissue phantoms in the near-infrared and mid-infrared to identify the wavelength dependence of laser damage thresholds from 1200-2500 nm. A high-energy regenerative amplifier and optical parametric amplifier outputting 100 femtosecond pulses with pulse energies up to 2 mJ were used to perform exposures and determine damage thresholds in transparent collagen gel tissue phantoms. Three-dimensional imaging, primarily optical coherence tomography, was used to evaluate tissue phantoms following exposure to determine ablation characteristics at the surface and within the bulk material. The determination of laser damage thresholds in the near-IR and mid-IR for ultrafast lasers will help to guide safety standards and establish the appropriate MPE levels for exposure sensitive ocular tissue such as the cornea. These data will help promote the safe use of ultrafast lasers for a wide range of applications.

  9. Pulsating instabilities and chaos in lasers

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, R G; Biswas, D J

    1985-01-01

    A detailed state of the art survey of deterministic chaos in laser systems is presented. The mechanism of single mode instability is discussed, including spontaneous and induced mode splitting and the threshold for laser instabilities. Single mode homogeneously broadened systems are addressed, including optically pumped far infrared lasers and near-resonantly pumped midinfrared systems. Single mode inhomogeneously broadened systems are considered, including the He-Xe laser and the He-Ne laser at 3.39 microns. Single mode lasers with external control parameter are discussed, as is the multimode laser. 297 references.

  10. Theoretical aspects of fibre laser cutting

    Energy Technology Data Exchange (ETDEWEB)

    Mahrle, A; Beyer, E, E-mail: achim.mahrle@iws.fraunhofer.d [University of Technology Dresden, Institute for Surface and Manufacturing Technology, PO Box, 01062 Dresden (Germany)

    2009-09-07

    Fibre lasers offer distinct advantages over established laser systems with respect to power efficiency, beam guidance and beam quality. Consequently, the potential of these new laser beam sources will be increasingly exploited for laser cutting applications that are conventionally carried out with CO{sub 2} lasers. However, theoretical estimates of the effective absorptivity at the cut front suggest that the shorter wavelength of the fibre laser in combination with its high focusability seems to be primarily advantageous for thin sheet metal cutting whereas the CO{sub 2} laser is probably still capable of cutting thicker materials more efficiently. This surprising result is a consequence of the absorptivity behaviour of metals that shows essential quantitative differences for the corresponding wavelengths of both laser sources as a function of the angle of incidence between the laser beam and the material to be cut. In evaluation of the revealed dependences, solution strategies for an improvement of the efficiency of fibre laser cutting of thicker metal sheets are suggested.

  11. An externally heated copper vapour laser

    International Nuclear Information System (INIS)

    Rochefort, P.A.; Sopchyshyn, F.C.; Selkirk, E.B.; Green, L.W.

    1993-08-01

    A pulsed Copper Vapour Laser (CVL), with a nominal 6 kHz repetition rate, was designed, build, and commissioned at Chalk River laboratories. The laser was required for Resonant Ionization Mass Spectroscopy (RIMS) experiments and for projects associated with Atomic Vapour laser Isotope Separation (AVLIS) studies. For the laser to operate, copper coupons position along the length of a ceramic tube must be heated sufficiently to create an appropriate vapour pressure. The AECL CVL uses an external heater element with a unique design to raise the temperature of the tube. The Cylindrical graphite heating element is shaped to compensate for the large radiation end losses of the laser tube. The use of an external heater saves the expensive high-current-voltage switching device from heating the laser tube, as in most commercial lasers. This feature is especially important given the intermittent usage typical of experimental research. As well, the heater enables better parametric control of the laser output when studying the lasing of copper (or other) vapour. This report outlines the lasing process in copper vapour, describes in detail all three major laser sub-systems: the laser body; the laser tube heater; the high voltage pulsed discharge; and, reports parametric measurements of the individual sub-systems and the laser system as a whole. Also included are normal operating procedures to heat up, run and shut down the laser

  12. Laser welding closed-loop power control

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    2003-01-01

    A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser.......A closed-loop control system is developed to maintain an even seam width on the root side of a laser weld by continually controlling the output laser power of a 1500 W CO2 laser....

  13. Computer-guided laser for neurosurgery.

    Science.gov (United States)

    Koivukangas, J; Louhisalmi, Y

    1990-01-01

    On the basis of over 40 neurosurgical laser operations, including CO2, Nd-YAG and simultaneous CO2/Nd-YAG laser procedures, a computer-guided system for spatial control of the laser beam has been developed. The pilot laser has several modes: it can direct the neurosurgeon along the central axis of the surgical microscope to stereotactically determined point-like targets or outline selected layers of underlying volume targets onto superficial surfaces such as scalp and cortex and onto the tissue at the appropriate depth. The active treatment laser can be guided by preoperative CT/MRI or intraoperative ultrasound image data for layer-by-layer resection of tumor. The laser system can be connected to the surgical field by rigid stereotactic means or by neuronavigator. In the present system, a special brain surgery adapter coordinates the imaging system and laser to the surgical field. Thus, the laser system can be used for image-guided surgical orientation, for demarcation of lesions and for actual layer-by-layer removal of tumor.

  14. Civilian applications of laser fusion

    International Nuclear Information System (INIS)

    Maniscalco, J.; Blink, J.; Buntzen, R.; Hovingh, J.; Meier, W.; Monsler, M.; Walker, P.

    1978-01-01

    The commercial aspects of laser fusion were evaluated in an attempt to relate the end products (neutrons and energy) to significant commercial applications. We have found that by far the largest markets and highest payoffs for laser fusion are associated with electric power production. Hence, much of this report evaluates the prospects of producing commercial electricity with laser fusion. To this end, we have described in detail a new and promising laser fusion concept--the liquid lithium waterfall reactor. In addition, we have taken the most attractive features from our laser fusion studies and used them to compare laser fusion to other long-range sources of energy (breeder reactors and solar energy). It is our contention that all three sources of electrical energy should be developed to the point where the final selections are primarily based on economic competitiveness. The other potential applications of laser fusion (fissile fuel production, synthetic fuel production, actinide burning, and propulsion) are also discussed, and our preliminary plan for the engineering development of laser fusion is presented

  15. Civilian applications of laser fusion

    International Nuclear Information System (INIS)

    Maniscalco, J.; Blink, J.; Buntzen, R.; Hovingh, J.; Meier, W.; Monsler, M.; Walker, P.

    1977-01-01

    The commercial aspects of laser fusion were evaluated in an attempt to relate the end products (neutrons and energy) to significant commercial applications. It was found that by far the largest markets and highest payoffs for laser fusion are associated with electric power production. Hence, much of this report evaluates the prospects of producing commercial electricity with laser fusion. To this end, we have described in detail a new and promising laser fusion concept--the liquid lithium waterfall reactor. In addition, we have taken the most attractive features from our laser studies and used them to compare laser fusion to other long-range sources of energy (breeder reactors and solar energy). It is our contention that all three sources of electrical energy should be developed to the point where the final selections are primarily based on economic competitiveness. The other potential applications of laser fusion (fissile fuel production, synthetic fuel production, actinide burning, and propulsion) are also discussed, and our preliminary plan for the engineering development of laser fusion is presented

  16. Laser precision microfabrication in Japan

    Science.gov (United States)

    Miyamoto, Isamu; Ooie, Toshihiko; Takeno, Shozui

    2000-11-01

    Electronic devices such as handy phones and micro computers have been rapidly expanding their market recent years due to their enhanced performance, down sizing and cost down. This has been realized by the innovation in the precision micro- fabrication technology of semiconductors and printed wiring circuit boards (PWB) where laser technologies such as lithography, drilling, trimming, welding and soldering play an important role. In phot lithography, for instance, KrF excimer lasers having a resolution of 0.18 micrometers has been used in production instead of mercury lamp. Laser drilling of PWB has been increased up to over 1000 holes per second, and approximately 800 laser drilling systems of PWB are expected to be delivered in the world market this year, and most of these laser processing systems are manufactured in Japan. Trend of laser micro-fabrication in Japanese industry is described along with recent topics of R&D, government supported project and future tasks of industrial laser precision micro-fabrication on the basis of the survey conducted by Japan laser Processing Society.

  17. Laser Division report 1986-89

    International Nuclear Information System (INIS)

    Monga, J.C.

    1995-01-01

    This report is a technical account of the scientific R and D activities pursued by the Laser Division of the Bhabha Atomic Research Centre during 1986-89. It covers in considerable detail, progress made in all the activities undertaken during that period in laser development and their application. The most important among them was the development of the 1 kJ glass laser. Studies of laser produced plasmas were pursued using a smaller 50 J chain and at different stages of development of the 1 kJ chain. Significant results of plasma instabilities and x-ray spectroscopic studies are reported. Several plasma diagnostic tools developed are also described which studied plasmas, radiation transport, and ablation induced shocks. Studies were also conducted on the performance of dye lasers during their development. Development of several CO 2 lasers, cw, pulsed, hybrid and wavelength turned/stabilized, have been described and their performance evaluated. Development and performance of a 16μ CF 4 laser is also given. An electron beam controlled CO 2 laser design is reported. (author). refs., figs., tabs

  18. Civilian applications of laser fusion

    Energy Technology Data Exchange (ETDEWEB)

    Maniscalco, J.; Blink, J.; Buntzen, R.; Hovingh, J.; Meier, W.; Monsler, M.; Walker, P.

    1977-11-17

    The commercial aspects of laser fusion were evaluated in an attempt to relate the end products (neutrons and energy) to significant commercial applications. It was found that by far the largest markets and highest payoffs for laser fusion are associated with electric power production. Hence, much of this report evaluates the prospects of producing commercial electricity with laser fusion. To this end, we have described in detail a new and promising laser fusion concept--the liquid lithium waterfall reactor. In addition, we have taken the most attractive features from our laser studies and used them to compare laser fusion to other long-range sources of energy (breeder reactors and solar energy). It is our contention that all three sources of electrical energy should be developed to the point where the final selections are primarily based on economic competitiveness. The other potential applications of laser fusion (fissile fuel production, synthetic fuel production, actinide burning, and propulsion) are also discussed, and our preliminary plan for the engineering development of laser fusion is presented.

  19. Small scale soft x-ray lasers

    International Nuclear Information System (INIS)

    Skinner, C.H.; DiCicco, D.S.; Kim, D.; Voorhees, D.; Suckewer, S.

    1990-01-01

    The widespread application of soft x-ray laser technology is contingent on the development of small scale soft x-ray lasers that do not require large laser facilities. Progress in the development of soft x-ray lasers pumped by a Nd laser of energy 6-12J is reported below. Application of an existing soft x-ray laser to x-ray microscopy has begun. A soft x-ray laser of output energy 1-3 mJ at 18,2 nm has been used to record high resolution images of biological specimens. The contact images were recorded on photoresist which was later viewed in a scanning electron microscope. The authors present a composite optical x-ray laser microscope design

  20. Bone Ablation at 2.94 mm Using the Free-Electron Laser and Er:YAG Laser

    Science.gov (United States)

    Ivanov, Borislav; Hakimian, Arman; Peavy, G. M.; Haglund, Richard

    2002-03-01

    Bone Ablation at 2.94 microns Using the Free-Electron Laser and Er:YAG Laser in Perfluorocarbon Compounds B. Ivanov^1, A. M. Hakimian^1, G. M. Peavy^2, R. F. Haglund, Jr.1 1Department of Physics and Astronomy, W. M. Keck Foundation Free-Electron Laser Center, Vanderbilt University, Nashville, TN 37235 2Beckman Laser Institute and Medical Clinic, College of Medicine, University of California, Irvine, CA 92612 We report studies on the efficiency of mid-IR laser ablation of cow cortical bone using the Vanderbilt free-electron laser (FEL), when irrigating the ablation zone with an inert and biocompatible perfluorocarbon compounds (PFC). At 2.94 microns, the bone matrix (mainly by water) absorbs the radiation while the PFCs transmit this wavelength, dissipate heat and acoustical stress, and prevent carbonization of the bone sample. The ablation rate, as a function of laser fluence, scanning speed and the type of PFC, was investigated. The laser fluence was estimated to be 5 J/cm^2 - 100 J/cm^2 with a laser focal spot diameter of 160 microns 500 microns and a scanning speed of 40 microns/s 2960 microns/s. The ablation rate was estimated from scanning electron microscopy to be 0.5 mm/s 2.4 mm/s. Comparisons of ablation rates with the FEL and a Er:YAG laser at 2.94 microns are being evaluated.

  1. Laser-plasma interaction with an adaptive optics wavefront-corrected laser beam

    International Nuclear Information System (INIS)

    Lewis, K.

    2008-12-01

    The propagation of an intense laser beam trough a preformed plasma is of particular interest in order to achieve laser inertial confinement fusion. Experiments carried out with a near-diffraction limited laser beam, producing a single hot spot interacting with the plasma, delivered new results, presented in this Ph.D. dissertation. In particular the first experimental observation of the filament instability confirms the numerous theoretical and numerical studies on the subject. Beam spreading and filament-ion thresholds are studied thanks to near-field and far-field images, with respect to laser intensity, time and space, and plasma transverse velocity. Same diagnostics have been applied to the stimulated Brillouin scattered light, enabling the first observation of the transverse Brillouin activity in the plasma. (author)

  2. Theoretical studies of solar pumped lasers

    Science.gov (United States)

    Harries, Wynford L.

    1990-01-01

    One concept for collecting solar energy is to use large solar collectors and then use lasers as energy converters whose output beams act as transmission lines to deliver the energy to a destination. The efficiency of the process would be improved if the conversion could be done directly using solar pumped lasers, and the possibility of making such lasers is studied. There are many applications for such lasers, and these are examined. By including the applications first, the requirements for the lasers will be more evident. They are especially applicable to the Space program, and include cases where no other methods of delivering power seem possible. Using the lasers for conveying information and surveillance is also discussed. Many difficulties confront the designer of an efficient system for power conversion. These involve the nature of the solar spectrum, the method of absorbing the energy, the transfer of power into laser beams, and finally, the far field patterns of the beams. The requirements of the lasers are discussed. Specific laser configurations are discussed. The thrust is into gas laser systems, because for space applications, the laser could be large, and also the medium would be uniform and not subject to thermal stresses. Dye and solid lasers are treated briefly. For gas lasers, a chart of the various possibilities is shown, and the various families of gas lasers divided according to the mechanisms of absorbing solar radiation and of lasing. Several specific models are analyzed and evaluated. Overall conclusions for the program are summarized, and the performances of the lasers related to the requirements of various applications.

  3. The laser desorption/laser ionization mass spectra of some methylated xanthines and the laser desorption of caffeine and theophylline from thin layer chromatography plates

    Science.gov (United States)

    Rogers, Kevin; Milnes, John; Gormally, John

    1993-02-01

    Laser desorption/laser ionization time-of-flight mass spectra of caffeine, theophylline, theobromine and xanthine are reported. These mass spectra are compared with published spectra obtained using electron impact ionization. Mass spectra of caffeine and theophylline obtained by IR laser desorption from thin layer chromatography plates are also described. The laser desorption of materials from thin layer chromatography plates is discussed.

  4. Some applications on laser material processing

    International Nuclear Information System (INIS)

    Oros, C.

    2005-01-01

    An overview of the state-of-the-art in laser material processing for a large types of lasers from IR (CO 2 laser, NdYAG laser) to UV (excimer laser) and different kinds of materials (metals, dielectrics) is given. Laser radiation has found a wide range of applications as machining tool for various kinds of materials processing. The machining geometry, the work piece geometry, the material properties and economic productivity claim for customized systems with special design for beam guiding, shaping and delivery in order to fully utilize the laser radiation for surface processing with optimum efficiency, maximum processing speed and high processing quality. The laser-material interaction involves complex processes of heating, melting, vaporization, ejection of atoms, ions, and molecules, shock waves, plasma initiation and plasma expansion. The interaction is dependent on the laser beam parameters (pulse duration, energy and wavelength), the solid target properties and the surrounding environments condition. Experimental results for laser surface melting and laser ablation are given. Also, assuming the applicability of a one dimensional model for short pulses used, and restricting condition to single-pulse exposure, the temperature rise on the target was calculated taking account of the finite optical absorption depth and pulse duration of the laser

  5. Physics of semiconductor lasers

    CERN Document Server

    Mroziewicz, B; Nakwaski, W

    2013-01-01

    Written for readers who have some background in solid state physics but do not necessarily possess any knowledge of semiconductor lasers, this book provides a comprehensive and concise account of fundamental semiconductor laser physics, technology and properties. The principles of operation of these lasers are therefore discussed in detail with the interrelations between their design and optical, electrical and thermal properties. The relative merits of a large number of laser structures and their parameters are described to acquaint the reader with the various aspects of the semiconductor l

  6. Tunable Microfluidic Dye Laser

    DEFF Research Database (Denmark)

    Olsen, Brian Bilenberg; Helbo, Bjarne; Kutter, Jörg Peter

    2003-01-01

    We present a tunable microfluidic dye laser fabricated in SU-8. The tunability is enabled by integrating a microfluidic diffusion mixer with an existing microfluidic dye laser design by Helbo et al. By controlling the relative flows in the mixer between a dye solution and a solvent......, the concentration of dye in the laser cavity can be adjusted, allowing the wavelength to be tuned. Wavelength tuning controlled by the dye concentration was demonstrated with macroscopic dye lasers already in 1971, but this principle only becomes practically applicable by the use of microfluidic mixing...

  7. Scanning Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1988-01-01

    A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

  8. Jet laser ion source

    International Nuclear Information System (INIS)

    Dem'yanov, A.V.; Sidorov, S.V.

    1994-01-01

    External laser injector of multicharged ions (MCI) is developed in which wide-aperture aberration-free wire gauze spherical shape electrodes are applied for effective MCI extraction from laser plasma and beam focusing. Axial plasma compression by solenoid magnetic field is used to reduce ion losses due to transverse movement of the scattering laser plasma. Transverse magnetic field created by another solenoid facilitates the effective laser plasma braking and consequently, leads to the narrowing of energy spectrum of plasma ions and its shift towards lower energies. 2 refs.; 3 figs

  9. Bringing Pulsed Laser Welding into Production

    DEFF Research Database (Denmark)

    Olsen, Flemmming Ove

    1996-01-01

    In this paper, some research and develop-ment activities within pulsed laser welding technology at the Tech-nical University of Denmark will be described. The laser group at the Insti-tute for Manufacturing Technology has nearly 20 years of experience in laser materials process-ing. Inter......-nationally the group is mostly known for its contri-butions to the development of the laser cutting process, but further it has been active within laser welding, both in assisting industry in bringing laser welding into production in several cases and in performing fundamental R & D. In this paper some research...... activities concerning the weldability of high alloyed austenitic stainless steels for mass production industry applying industrial lasers for fine welding will be described. Studies on hot cracking sensitivity of high alloyed austenitic stainless steel applying both ND-YAG-lasers and CO2-lasers has been...

  10. A task for laser cutting of lamellae with TruLaser 1030

    OpenAIRE

    Lazov, Lyubomir; Deneva, Hristina; Narica, Pavels

    2015-01-01

    The growing development of manufacturing, automotive, aerospace and other sectors in the industry generates the necessity to continuously expanding on modifications of electrical machinery and equipments which are used in them, as well as to improve their performance and reliability. The report presents some results from a study to the process of laser cutting through melting on lamellae for rotor and stator packages by using the laser system TruLaser 1030. Some functional dependencies are of...

  11. Research on interaction of laser light and non-metals. Evaluation of laser irradiation behavior to concrete

    International Nuclear Information System (INIS)

    Yamada, Tomonori; Muramatsu, Toshiharu

    2015-02-01

    In this study the response of hardened cement pastes, which are a major component of concrete, to laser irradiation was investigated under various experimental conditions aiming at the future application to “laser-processing” of concrete. (1) 75 tests were performed with combinations of following experimental conditions: (a) a water/cement ratio of the hardened cement pastes was either of 0.25, 0.30, or 0.35; (b) a laser power density was either of 100, 200, 300, 400, or 500 W/cm 2 ; and (c) laser irradiation duration was ranging from 1 to 40 seconds. It was found that hardened cement paste subjected to laser irradiation explodes very easily to be hollowed in all the experimental conditions; this response is applicable to “laser-drilling” of a hardened cement paste. The “laser-drilling” speeds up following to laser power increment or to irradiation time extension. It was also found that samples tend to melt rather than explode under the irradiation with a smaller laser power density (100 W/cm 2 ) at a high water/cement ratio (0.35). (2) Totally 75 laser irradiation tests for fixed mortar blocks were performed with combinations of following experimental conditions: (a) fine aggregate in the mortar blocks was either of quartz, limestone, or Nachiguro-ishi; (b) a laser power density was either of 100, 200, 300, 400, or 500 W/cm 2 ; and (c) laser irradiation duration was ranging from 0.2 to 40 seconds. Although it was found that all kinds of the mortar fuse under laser irradiation after all, difference in the response to laser irradiation among the mortars was also found; energy density required to fuse the mortar including limestone was larger than that required to fuse the mortar including quartz or Nachiguro-ishi. (author)

  12. E-beam-pumped semiconductor lasers

    Science.gov (United States)

    Rice, Robert R.; Shanley, James F.; Ruggieri, Neil F.

    1995-04-01

    The collapse of the Soviet Union opened many areas of laser technology to the West. E-beam- pumped semiconductor lasers (EBSL) were pursued for 25 years in several Soviet Institutes. Thin single crystal screens of II-VI alloys (ZnxCd1-xSe, CdSxSe1-x) were incorporated in laser CRTs to produce scanned visible laser beams at average powers greater than 10 W. Resolutions of 2500 lines were demonstrated. MDA-W is conducting a program for ARPA/ESTO to assess EBSL technology for high brightness, high resolution RGB laser projection application. Transfer of II-VI crystal growth and screen processing technology is underway, and initial results will be reported. Various techniques (cathodoluminescence, one- and two-photon laser pumping, etc.) have been used to assess material quality and screen processing damage. High voltage (75 kV) video electronics were procured in the U.S. to operate test EBSL tubes. Laser performance was documented as a function of screen temperature, beam voltage and current. The beam divergence, spectrum, efficiency and other characteristics of the laser output are being measured. An evaluation of the effect of laser operating conditions upon the degradation rate is being carried out by a design-of-experiments method. An initial assessment of the projected image quality will be performed.

  13. Fractional laser skin resurfacing.

    Science.gov (United States)

    Alexiades-Armenakas, Macrene R; Dover, Jeffrey S; Arndt, Kenneth A

    2012-11-01

    Laser skin resurfacing (LSR) has evolved over the past 2 decades from traditional ablative to fractional nonablative and fractional ablative resurfacing. Traditional ablative LSR was highly effective in reducing rhytides, photoaging, and acne scarring but was associated with significant side effects and complications. In contrast, nonablative LSR was very safe but failed to deliver consistent clinical improvement. Fractional LSR has achieved the middle ground; it combined the efficacy of traditional LSR with the safety of nonablative modalities. The first fractional laser was a nonablative erbium-doped yttrium aluminum garnet (Er:YAG) laser that produced microscopic columns of thermal injury in the epidermis and upper dermis. Heralding an entirely new concept of laser energy delivery, it delivered the laser beam in microarrays. It resulted in microscopic columns of treated tissue and intervening areas of untreated skin, which yielded rapid reepithelialization. Fractional delivery was quickly applied to ablative wavelengths such as carbon dioxide, Er:YAG, and yttrium scandium gallium garnet (2,790 nm), providing more significant clinical outcomes. Adjustable laser parameters, including power, pitch, dwell time, and spot density, allowed for precise determination of percent surface area, affected penetration depth, and clinical recovery time and efficacy. Fractional LSR has been a significant advance to the laser field, striking the balance between safety and efficacy.

  14. The argon excimer laser

    International Nuclear Information System (INIS)

    Wrobel, W.G.

    1981-02-01

    The electron-beam-pumped argon eximer laser is investigated and tuned for the first time. The electron beam is generated by means of an improved coaxial field emmision diode in which argon gas is excited with power densities of 0.3 GW/cm 3 for 18 ns. The processes in the excited gas of 20 to 65 bar are described in the context of a kinetic model as a sequence of stationary states. Investigations of the amplified spontaneous emission (superfluorescence) confirm the predictions of this model. Only the absorption due to the excited Ar atoms is anomalously high. Reproducible operation of the argon eximer laser was achieved in a wide pressure range with various resonator arrangements. The wavelength of this shortest wavelength of this shortest wavelength excimer laser is 126 nm, the laser line width approx. 1.7 nm, the pulse length 7 to 13 ns, and the laser power 250 kW. The laser emission is tuned from 123.2 nm to 128.4 nm by two different methods (diffraction grating and prism). This tunable laser is thus the one with the shortest wavelength at present. Its line width is 0.25 to 0.4 nm, and the power ue 1.7 kW. (orig.)

  15. Direct solar-pumped lasers

    Science.gov (United States)

    Lee, J. H.; Shiu, Y. J.; Weaver, W. R.

    1980-01-01

    The feasibility of direct solar pumping of an iodine photodissociation laser at lambda = 1.315 microns was investigated. Threshold inversion density and effect of elevated temperature (up to 670 K) on the laser output were measured. These results and the concentration of solar radiation required for the solar pumped iodine laser are discussed.

  16. High Efficiency Mask Based Laser Materials Processing with TEA-CO2 - and Excimer Laser

    DEFF Research Database (Denmark)

    Bastue, Jens; Olsen, Flemmming Ove

    1997-01-01

    In general, mask based laser materials processing techniques suffer from a very low energy efficiency. We have developed a simple device called an energy enhancer, which is capable of increasing the energy efficiency of typical mask based laser materials processing systems. A short review of the ...... line marking with TEA-CO2 laser of high speed canning lines. The second one is manufactured for marking or microdrilling with excimer laser....

  17. Laser engineering of microbial systems

    Science.gov (United States)

    Yusupov, V. I.; Gorlenko, M. V.; Cheptsov, V. S.; Minaev, N. V.; Churbanova, E. S.; Zhigarkov, V. S.; Chutko, E. A.; Evlashin, S. A.; Chichkov, B. N.; Bagratashvili, V. N.

    2018-06-01

    A technology of laser engineering of microbial systems (LEMS) based on the method of laser-induced transfer of heterogeneous mixtures containing microorganisms (laser bioprinting) is described. This technology involves laser printing of soil microparticles by focusing near-infrared laser pulses on a specially prepared gel/soil mixture spread onto a gold-coated glass plate. The optimal range of laser energies from the point of view of the formation of stable jets and droplets with minimal negative impact on living systems of giant accelerations, laser pulse irradiation, and Au nanoparticles was found. Microsamples of soil were printed on glucose-peptone-yeast agar plates to estimate the LEMS process influence on structural and morphological microbial diversity. The obtained results were compared with traditionally treated soil samples. It was shown that LEMS technology allows significantly increasing the biodiversity of printed organisms and is effective for isolating rare or unculturable microorganisms.

  18. Proceedings of national laser symposium (NLS-2000)

    International Nuclear Information System (INIS)

    Mallik, Amitav; Srivastava, K.N.; Pal, Suranjan

    2000-01-01

    This proceedings comprise of a series of invited talks on selected topics in lasers and wide range of contributed papers. The main topics are laser physics and research, laser devices and technology, laser materials and spectroscopy, quantum optics, non-linear optics ultra-fast phenomenon, laser produced plasma, high power lasers, laser instrumentation, medical applications and industrial applications of lasers and fiber optics. The papers relevant to INIS Database are indexed separately

  19. Crystal growth, spectral properties, and laser demonstration of laser crystal Nd:LYSO

    Science.gov (United States)

    Li, D. Z.; Xu, X. D.; Zhou, D. H.; Zhuang, S. D.; Wang, Z. P.; Xia, C. T.; Wu, F.; Xu, J.

    2010-11-01

    A Nd:LYSO crystal has been grown by the Czochralski technique. The cell parameters were analyzed with X-ray diffraction (XRD). The Judd-Ofelt intense parameters Ω2,4,6 were obtained to be 2.65, 5.75, and 7.37×10-20 cm2, respectively. The absorption and emission cross sections and the branching ratios were calculated. The large absorption cross section (6.14×10-20 cm2) and broad absorption band (5 nm) around 811 nm indicate that this crystal can be pumped efficiently by laser diodes. The broad emission band from the 4F3/2 multiplet shows that the crystal is a promising medium for ultrashort pulse lasers. Pumped by a laser diode, the maximum 814 mW continuous-wave laser output has been obtained with a slope efficiency of 28.9%. All the results show that this crystal is a promising laser material.

  20. Crystal growth, spectral properties, and laser demonstration of laser crystal Nd:LYSO

    International Nuclear Information System (INIS)

    Li, D Z; Xu, X D; Zhou, D H; Xia, C T; Wu, F; Zhuang, S D; Wang, Z P; Xu, J

    2010-01-01

    A Nd:LYSO crystal has been grown by the Czochralski technique. The cell parameters were analyzed with X-ray diffraction (XRD). The Judd-Ofelt intense parameters Ω 2,4,6 were obtained to be 2.65, 5.75, and 7.37×10 -20 cm 2 , respectively. The absorption and emission cross sections and the branching ratios were calculated. The large absorption cross section (6.14×10 -20 cm 2 ) and broad absorption band (5 nm) around 811 nm indicate that this crystal can be pumped efficiently by laser diodes. The broad emission band from the 4 F 3/2 multiplet shows that the crystal is a promising medium for ultrashort pulse lasers. Pumped by a laser diode, the maximum 814 mW continuous-wave laser output has been obtained with a slope efficiency of 28.9%. All the results show that this crystal is a promising laser material

  1. Experimental signatures of direct-laser-acceleration-assisted laser wakefield acceleration

    Science.gov (United States)

    Shaw, J. L.; Lemos, N.; Marsh, K. A.; Froula, D. H.; Joshi, C.

    2018-04-01

    The direct laser acceleration (DLA) of electrons in a laser wakefield accelerator (LWFA) operating in the forced or quasi-blowout regimes has been investigated through experiment and simulation. When there is a significant overlap between the trapped electrons and the drive laser in a LWFA cavity, the resulting electrons can gain energy from both the LWFA and the DLA mechanisms. Experimental work investigates the properties of the electron beams produced in a LWFA with ionization injection by dispersing those beams in the direction perpendicular to the laser polarization. These electron beams show certain spectral features that are characteristic of DLA. These characteristic features are reproduced using particle-in-cell simulations, where particle tracking was used to elucidate the roles of LWFA and DLA to the energy gain of the electrons in this experimental regime and to demonstrate that such spectral features are definitive signatures of the presence of DLA in LWFA.

  2. HOMOGENIZERS OF LASER RADIATION FABRICATED BY LASER GRAVING OF POLYMER FILMS

    Directory of Open Access Journals (Sweden)

    V. K. Balya

    2013-01-01

    Full Text Available The article deals with homogenizers of laser radiation based on crossing micro-prism structures and random diffusers by laser ablation of thermo-sensitive film and subsequent nano-imprint copying.

  3. Development of automatic laser welding system

    International Nuclear Information System (INIS)

    Ohwaki, Katsura

    2002-01-01

    Laser are a new production tool for high speed and low distortion welding and applications to automatic welding lines are increasing. IHI has long experience of laser processing for the preservation of nuclear power plants, welding of airplane engines and so on. Moreover, YAG laser oscillators and various kinds of hardware have been developed for laser welding and automation. Combining these welding technologies and laser hardware technologies produce the automatic laser welding system. In this paper, the component technologies are described, including combined optics intended to improve welding stability, laser oscillators, monitoring system, seam tracking system and so on. (author)

  4. Solid-state laser engineering

    CERN Document Server

    Koechner, Walter

    1996-01-01

    Solid-State Laser Engineering, written from an industrial perspective, discusses in detail the characteristics, design, construction, and performance of solid-state lasers. Emphasis is placed on engineering and practical considerations; phenomenological aspects using models are preferred to abstract mathematical derivations. This new edition has extensively been updated to account for recent developments in the areas of diode-laser pumping, mode locking, ultrashort-pulse generation etc. Walter Koechner received a doctorate in Electrical Engineering from the University of Technology in Vienna, Austria, in 1965. He has published numerous papers in the fields of solid-state physics, optics, and lasers. Dr. Koechner is founder and president of Fibertek, Inc., a research firm specializing in the design, development, and production of advanced solid-state lasers, optical radars, and remote-sensing systems.

  5. Theoretical studies of solar-pumped lasers

    Science.gov (United States)

    Harries, W. L.

    1983-01-01

    Possible types of lasers were surveyed for solar power conversion. The types considered were (1) liquid dye lasers, (2) vapor dye lasers, and (3) nondissociative molecular lasers. These are discussed.

  6. Femtosecond Cr:LiSAF and Cr:LiCAF lasers pumped by tapered diode lasers.

    Science.gov (United States)

    Demirbas, Umit; Schmalz, Michael; Sumpf, Bernd; Erbert, Götz; Petrich, Gale S; Kolodziejski, Leslie A; Fujimoto, James G; Kärtner, Franz X; Leitenstorfer, Alfred

    2011-10-10

    We report compact, low-cost and efficient Cr:Colquiriite lasers that are pumped by high brightness tapered laser diodes. The tapered laser diodes provided 1 to 1.2 W of output power around 675 nm, at an electrical-to-optical conversion efficiency of about 30%. Using a single tapered diode laser as the pump source, we have demonstrated output powers of 500 mW and 410 mW together with slope efficiencies of 47% and 41% from continuous wave (cw) Cr:LiSAF and Cr:LiCAF lasers, respectively. In cw mode-locked operation, sub-100-fs pulse trains with average power between 200 mW and 250 mW were obtained at repetition rates around 100 MHz. Upon pumping the Cr:Colquiriite lasers with two tapered laser diodes (one from each side of the crystal), we have observed scaling of cw powers to 850 mW in Cr:LiSAF and to 650 mW in Cr:LiCAF. From the double side pumped Cr:LiCAF laser, we have also obtained ~220 fs long pulses with 5.4 nJ of pulse energy at 77 MHz repetition rate. These are the highest energy levels reported from Cr:Colquiriite so far at these repetition rates. Our findings indicate that tapered diodes in the red spectral region are likely to become the standard pump source for Cr:Colquiriite lasers in the near future. Moreover, the simplified pumping scheme might facilitate efficient commercialization of Cr:Colquiriite systems, bearing the potential to significantly boost applications of cw and femtosecond lasers in this spectral region (750-1000 nm).

  7. Characterization of hard coatings produced by laser cladding using laser-induced breakdown spectroscopy technique

    Energy Technology Data Exchange (ETDEWEB)

    Varela, J.A.; Amado, J.M.; Tobar, M.J.; Mateo, M.P.; Yañez, A.; Nicolas, G., E-mail: gines@udc.es

    2015-05-01

    Highlights: • Chemical mapping and profiling by laser-induced breakdown spectroscopy (LIBS) of coatings produced by laser cladding. • Production of laser clads using tungsten carbide (WC) and nickel based matrix (NiCrBSi) powders. • Calibration by LIBS of hardfacing alloys with different WC concentrations. - Abstract: Protective coatings with a high abrasive wear resistance can be obtained from powders by laser cladding technique, in order to extend the service life of some industrial components. In this work, laser clad layers of self-fluxing NiCrBSi alloy powder mixed with WC powder have been produced on stainless steel substrates of austenitic type (AISI 304) in a first step and then chemically characterized by laser-induced breakdown spectroscopy (LIBS) technique. With the suitable laser processing parameters (mainly output power, beam scan speed and flow rate) and powders mixture proportions between WC ceramics and NiCrBSi alloys, dense pore free layers have been obtained on single tracks and on large areas with overlapped tracks. The results achieved by LIBS technique and applied for the first time to the analysis of laser clads provided the chemical composition of the tungsten carbides in metal alloy matrix. Different measurement modes (multiple point analyses, depth profiles and chemical maps) have been employed, demonstrating the usefulness of LIBS technique for the characterization of laser clads based on hardfacing alloys. The behavior of hardness can be explained by LIBS maps which evidenced the partial dilution of some WC spheres in the coating.

  8. Vacuum laser acceleration using a radially polarized CO sub 2 laser beam

    CERN Document Server

    Liu, Y; He, P

    1999-01-01

    Utilizing the high-power, radially polarized CO sub 2 laser and high-quality electron beam at the Brookhaven Accelerator Test Facility, a vacuum laser acceleration scheme is proposed. In this scheme, optics configuration is simple, a small focused beam spot size can be easily maintained, and optical damage becomes less important. At least 0.5 GeV/m acceleration gradient is achievable by 1 TW laser power.

  9. Trends in laser-plasma-instability experiments for laser fusion

    International Nuclear Information System (INIS)

    Drake, R.P.

    1991-01-01

    Laser-plasma instability experiments for laser fusion have followed three developments. These are advances in the technology and design of experiments, advances in diagnostics, and evolution of the design of high-gain targets. This paper traces the history of these three topics and discusses their present state. Today one is substantially able to produce controlled plasma conditions and to diagnose specific instabilities within such plasmas. Experiments today address issues that will matter for future laser facilities. Such facilities will irradiate targets with ∼1 MJ of visible or UV light pulses that are tens of nanoseconds in duration, very likely with a high degree of spatial and temporal incoherence. 58 refs., 4 figs

  10. Mode-locked solid state lasers using diode laser excitation

    Science.gov (United States)

    Holtom, Gary R [Boston, MA

    2012-03-06

    A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. An asymmetric cavity provides relatively large beam spot sizes in gain medium to permit efficient coupling to a volume pumped by a laser diode bar. The cavity can include a collimation region with a controlled beam spot size for insertion of a saturable absorber and dispersion components. Beam spot size is selected to provide stable mode locking based on Kerr lensing. Pulse durations of less than 100 fs can be achieved in Yb:KGW.

  11. Coatings for laser fusion

    International Nuclear Information System (INIS)

    Lowdermilk, W.H.

    1981-01-01

    Optical coatings are used in lasers systems for fusion research to control beam propagation and reduce surface reflection losses. The performance of coatings is important in the design, reliability, energy output, and cost of the laser systems. Significant developments in coating technology are required for future lasers for fusion research and eventual power reactors

  12. Theoretical model for a background noise limited laser-excited optical filter for doubled Nd lasers

    Science.gov (United States)

    Shay, Thomas M.; Garcia, Daniel F.

    1990-01-01

    A simple theoretical model for the calculation of the dependence of filter quantum efficiency versus laser pump power in an atomic Rb vapor laser-excited optical filter is reported. Calculations for Rb filter transitions that can be used to detect the practical and important frequency-doubled Nd lasers are presented. The results of these calculations show the filter's quantum efficiency versus the laser pump power. The required laser pump powers required range from 2.4 to 60 mW/sq cm of filter aperture.

  13. CO2 laser cutting

    CERN Document Server

    Powell, John

    1998-01-01

    The laser has given manufacturing industry a new tool. When the laser beam is focused it can generate one of the world's most intense energy sources, more intense than flames and arcs, though similar to an electron beam. In fact the intensity is such that it can vaporise most known materials. The laser material processing industry has been growing swiftly as the quality, speed and new manufacturing possibilities become better understood. In the fore of these new technologies is the process of laser cutting. Laser cutting leads because it is a direct process substitu­ tion and the laser can usually do the job with greater flexibility, speed and quality than its competitors. However, to achieve these high speeds with high quality con­ siderable know how and experience is required. This information is usually carefully guarded by the businesses concerned and has to be gained by hard experience and technical understanding. Yet in this book John Powell explains in lucid and almost non­ technical language many o...

  14. Morphological and spectroscopic characterization of laser-ablated tungsten at various laser irradiances

    Energy Technology Data Exchange (ETDEWEB)

    Akram, Mahreen; Bashir, Shazia; Hayat, Asma; Mahmood, Khaliq; Dawood, Asadullah [Government College University, Centre for Advanced Studies in Physics, Lahore (Pakistan); Rafique, Muhammad Shahid [University of Engineering and Technology, Department of Physics, Lahore (Pakistan); Bashir, M.F. [COMSATS Institute of Information Technology, Department of Physics, Lahore (Pakistan)

    2015-06-15

    The variation in surface morphology and plasma parameters of laser irradiated tungsten has been investigated as a function of irradiance. For this purpose, Nd:YAG laser (1064 nm, 10 ns, 10 Hz) is employed. Tungsten targets were exposed to various laser irradiances ranging from 6 to 50 GW/cm{sup 2} under ambient environment of argon at a pressure of 20 Torr. Scanning electron microscope analysis has been performed to analyze the surface modification of irradiated tungsten. It revealed the formation of micro- and nanoscale surface structures. In central ablated area, distinct grains and crack formation are observed, whereas peripheral ablated areas are dominated by cones and pinhole formation. It was observed that at irradiances exceeding a value of 13 GW/cm{sup 2}, the morphological trend of the observed structures has been changed from erosion to melting and re-deposition dominant phase. Ablation efficiency as a function of laser irradiance has also been investigated by measuring the crater depth using surface profilometry analysis. It is found to be maximum at an irradiance of 13 GW/cm{sup 2} and decreases at high laser irradiances. In order to correlate the accumulated effects of plasma parameters with the surface modification, laser-induced breakdown spectroscopy analysis has been performed. The electron temperature and number density of tungsten plasma have been evaluated at various laser irradiances. Initially with the increase of the laser irradiance up to 13 GW/cm{sup 2}, an increasing trend is observed for both plasma parameters due to enhanced energy deposition. Afterward, a decreasing trend is achieved which is attributed to the shielding effect. With further increase in irradiance, a saturation stage comes and insignificant changes are observed in plasma parameters. This saturation is explainable on the basis of the formation of a self-regulating regime near the target surface. Surface modifications of laser irradiated tungsten have been correlated with

  15. Laser tissue interactions: an update for otolaryngology

    Science.gov (United States)

    Reinisch, Lou

    2000-05-01

    We review the laser, characteristics of laser light, the delivery of laser light, pulse lengths and laser tissue interactions. We review these parameters and how they have changed over the history of the laser and how we expect them to change in the future. This survey of laser use is targeted to the otolaryngologist. Very little background in lasers is necessary to follow the discussion. This is intended to introduce and reintroduce laser technology.

  16. Laser corrective surgery with fractional carbon dioxide laser following full-thickness skin grafts

    Directory of Open Access Journals (Sweden)

    Emily Forbat

    2017-01-01

    Full Text Available Full-thickness skin grafts (FTSGs are frequently used to treat patients with burn injuries and to repair defects rendered by excisional (including Mohs surgery. The evidence for corrective laser surgery after scar formation is well established. With regard to laser treatment of FTSG, the evidence is sparse. Laser treatment after FTSG is a novel concept, with minimal literature. We present a case series, one of the first to our knowledge, of the treatment of FTSG with fractional CO2 laser in five patients after Mohs surgery.

  17. Faraday cup measurements of a laser-induced plasma for a laser-proton acceleration

    International Nuclear Information System (INIS)

    Park, Seong Hee; Jeong, Young Uk; Lee, Ki Tae

    2006-01-01

    Experiments for the generation of laser-induced protons were performed in collaboration with Advanced Photonics Research Institute (APRI). An intensity of 3 X 10 18 W/cm 2 was delivered to a 17-μm Al target, and the Faraday Cup signals of the charged particles generated by the laser-plasma interaction were measured. In this paper, we discuss the first experimental results of laser-induced proton generation using the APRI laser and report on the feasibility of current measurement for charged-particles when using a Faraday cup.

  18. Electric motor for laser-mechanical drilling

    Science.gov (United States)

    Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

    2015-07-07

    A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for advancing a borehole. High power laser drilling system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam through the electrical motor.

  19. Binding Mechanisms in Selective Laser Sintering and Selective Laser Melting

    NARCIS (Netherlands)

    Kruth, J.P.; Mercelis, P.; Van Vaerenbergh, J.; van Vaerenbergh, J.; Froyen, L.; Rombouts, M.

    2005-01-01

    Purpose – This paper provides an overview of the different binding mechanisms in selective laser sintering (SLS) and selective laser melting (SLM), thus improving the understanding of these processes. Design/methodology/approach – A classification of SLS/SLM processes was developed, based on the

  20. Lasers in atomic, molecular and nuclear physics

    International Nuclear Information System (INIS)

    Letokhov, V.S.

    1986-01-01

    This book presents papers on laser applications in atomic, molecular and nuclear physics. Specifically discussed are: laser isotope separation; laser spectroscopy of chlorophyll; laser spectroscopy of molecules and cell membranes; laser detection of atom-molecule collisions and lasers in astrophysics