Pub Date : 2018-12-20DOI: 10.5772/INTECHOPEN.80374
A. Sadrolhosseini, M. Mahdi, Farideh Alizadeh, S. Rashid
Recently, the synthesis and application of metal and ceramic nanoparticle are significant subject in science and engineering. The metal nanoparticles such as silver, gold, and copper nanoparticles have more application in material science, nanomedicine, electronic, photonic, and art. One of the green methods for preparation of metal nanoparticles is laser ablation technique that offers a unique tool for nanofabrication of nanoparticles. In this technique, the high-power laser ablates the metal plate and the nanoparticles are formed in the liquid. The properties of nanoparticles using laser ablation are unique, and they are not reproducible by any other method such as chemical methods. The important parameters to produce the metal nanoparticles are energy, wavelength, repetition rate of laser, ablation time, and absorption of an aqueous solution. Laser ablation is a simple method for fabricating the metal nanoparticles without surfactant or chemical addition. In this chapter, the mechanism of formation of metal nanoparticles in liquid, significant parameters for using the laser ablation technique to prepare the metal nanoparticles, and the preparation of silver, gold and copper nanoparticles will be reviewed. nanoparticles, gold nanoparticles, copper nanoparticles, mechanism of laser ablation in liquid, effect of wavelength in laser ablation, effect of temperature in laser ablation, laser ablation setup
{"title":"Laser Ablation Technique for Synthesis of Metal Nanoparticle in Liquid","authors":"A. Sadrolhosseini, M. Mahdi, Farideh Alizadeh, S. Rashid","doi":"10.5772/INTECHOPEN.80374","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.80374","url":null,"abstract":"Recently, the synthesis and application of metal and ceramic nanoparticle are significant subject in science and engineering. The metal nanoparticles such as silver, gold, and copper nanoparticles have more application in material science, nanomedicine, electronic, photonic, and art. One of the green methods for preparation of metal nanoparticles is laser ablation technique that offers a unique tool for nanofabrication of nanoparticles. In this technique, the high-power laser ablates the metal plate and the nanoparticles are formed in the liquid. The properties of nanoparticles using laser ablation are unique, and they are not reproducible by any other method such as chemical methods. The important parameters to produce the metal nanoparticles are energy, wavelength, repetition rate of laser, ablation time, and absorption of an aqueous solution. Laser ablation is a simple method for fabricating the metal nanoparticles without surfactant or chemical addition. In this chapter, the mechanism of formation of metal nanoparticles in liquid, significant parameters for using the laser ablation technique to prepare the metal nanoparticles, and the preparation of silver, gold and copper nanoparticles will be reviewed. nanoparticles, gold nanoparticles, copper nanoparticles, mechanism of laser ablation in liquid, effect of wavelength in laser ablation, effect of temperature in laser ablation, laser ablation setup","PeriodicalId":250018,"journal":{"name":"Laser Technology and its Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116966608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-18DOI: 10.5772/INTECHOPEN.81060
Babar Ibrahim Muhammad
This chapter describes double clad fiber along with cladding pump technique in which pump light is coupled in the inner cladding of fiber thereby interacting with doped core through total internal reflection. Lasers operating in continuous wave mode have limited output power. Their output power can be enhanced to a great extent by concentrating the available energy in a single or in a periodic sequence of optical pulses. This is achieved by Q-switch and modelock techniques. Q-switched and modelocked lasers can be real-ized by active and passive means. Active technique is based on active loss modulation by using mechanical, electro-optic or acousto-optic based modulators. However, such techniques require complicated electronic circuits and have limited gain bandwidth. The attention then moves towards the passive technique which is low cost, compact in size, gives reliable operation without high voltages and provides simple cavity design without need for external electronics. Passive technique employs a saturable absorber, based on materials like carbon nanotubes, graphene, molybdenum di-sulfide etc. A brief descrip- tion of pulsed fiber lasers and solitons in view of modelocking are described in the text. Moreover examples of Q-switched and modelocked lasers are also presented by using Thulium-Ytterbium co-doped double clad fiber. A cladding pump technique is employed for the purpose.
{"title":"Cladding Pumped Thulium-Ytterbium Short Pulse Fiber Lasers","authors":"Babar Ibrahim Muhammad","doi":"10.5772/INTECHOPEN.81060","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.81060","url":null,"abstract":"This chapter describes double clad fiber along with cladding pump technique in which pump light is coupled in the inner cladding of fiber thereby interacting with doped core through total internal reflection. Lasers operating in continuous wave mode have limited output power. Their output power can be enhanced to a great extent by concentrating the available energy in a single or in a periodic sequence of optical pulses. This is achieved by Q-switch and modelock techniques. Q-switched and modelocked lasers can be real-ized by active and passive means. Active technique is based on active loss modulation by using mechanical, electro-optic or acousto-optic based modulators. However, such techniques require complicated electronic circuits and have limited gain bandwidth. The attention then moves towards the passive technique which is low cost, compact in size, gives reliable operation without high voltages and provides simple cavity design without need for external electronics. Passive technique employs a saturable absorber, based on materials like carbon nanotubes, graphene, molybdenum di-sulfide etc. A brief descrip- tion of pulsed fiber lasers and solitons in view of modelocking are described in the text. Moreover examples of Q-switched and modelocked lasers are also presented by using Thulium-Ytterbium co-doped double clad fiber. A cladding pump technique is employed for the purpose.","PeriodicalId":250018,"journal":{"name":"Laser Technology and its Applications","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122606844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.79828
S. Nicoară
Retinopathy of prematurity (ROP) is a largely preventable cause of visual impairment in children. The golden standard of treatment in ROP is the laser photocoagulation of the nonvascularized retina. The most vulnerable period when ROP is at high risk of rapid progression is comprised between 34 and 35 weeks postconceptional age (PCA) and 36–37 weeks PCA.We carried out a retrospective study in which we included all the ROP cases treated by indirect diode laser photocoagulation between January 1, 2006, and December 31, 2017, totalizing 110 premature infants of which, 60 were males (54.54%) and 50, females (45.45%). Mean gestational age (GA) was 28.30 weeks and mean birth weight (BW) was 1121 grams in our series. Of the 110 preterm infants, 74 were the result of single pregnancies (67.27%) and 36 of multiple pregnancies (32.72%). At the moment of treatment, the mean postnatal age (PNA) was 8.38 weeks and the mean PCA, 37.02 weeks. ROP regressed after laser treatment in 185 eyes (88.09%). Statistical tests proved that regression rate was significantly worse in aggressive posterior ROP as compared with stage 3 zone 2 and stage 3 zone 1 ROP (odds ratio = 13.53, relative risk = 7.79, P < .001).
{"title":"Indirect Diode Laser in the Treatment of Retinopathy of Prematurity","authors":"S. Nicoară","doi":"10.5772/INTECHOPEN.79828","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.79828","url":null,"abstract":"Retinopathy of prematurity (ROP) is a largely preventable cause of visual impairment in children. The golden standard of treatment in ROP is the laser photocoagulation of the nonvascularized retina. The most vulnerable period when ROP is at high risk of rapid progression is comprised between 34 and 35 weeks postconceptional age (PCA) and 36–37 weeks PCA.We carried out a retrospective study in which we included all the ROP cases treated by indirect diode laser photocoagulation between January 1, 2006, and December 31, 2017, totalizing 110 premature infants of which, 60 were males (54.54%) and 50, females (45.45%). Mean gestational age (GA) was 28.30 weeks and mean birth weight (BW) was 1121 grams in our series. Of the 110 preterm infants, 74 were the result of single pregnancies (67.27%) and 36 of multiple pregnancies (32.72%). At the moment of treatment, the mean postnatal age (PNA) was 8.38 weeks and the mean PCA, 37.02 weeks. ROP regressed after laser treatment in 185 eyes (88.09%). Statistical tests proved that regression rate was significantly worse in aggressive posterior ROP as compared with stage 3 zone 2 and stage 3 zone 1 ROP (odds ratio = 13.53, relative risk = 7.79, P < .001).","PeriodicalId":250018,"journal":{"name":"Laser Technology and its Applications","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121308044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.80841
Yachen Gao, D. Kong
The special nonlinear optical response of noble metal nanoparticles (MNPs) when exposed to intense laser radiation has induced novel applications in nonlinear spectroscopy, optoelectronics, and optical switchers and limiters. In this chapter, recent results on the nonlinear optical properties of MNPs (including gold, silver, palladium, and platinum) have been discussed. Some specific optical nonlinear properties, such as nonlinear refraction, saturable absorption and reverse saturable absorption, two-photon absorption, and optical limiting, for femtosecond, picosecond, and nanosecond laser pulses, have been covered.
{"title":"Nonlinear Optical Response of Noble Metal Nanoparticles","authors":"Yachen Gao, D. Kong","doi":"10.5772/INTECHOPEN.80841","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.80841","url":null,"abstract":"The special nonlinear optical response of noble metal nanoparticles (MNPs) when exposed to intense laser radiation has induced novel applications in nonlinear spectroscopy, optoelectronics, and optical switchers and limiters. In this chapter, recent results on the nonlinear optical properties of MNPs (including gold, silver, palladium, and platinum) have been discussed. Some specific optical nonlinear properties, such as nonlinear refraction, saturable absorption and reverse saturable absorption, two-photon absorption, and optical limiting, for femtosecond, picosecond, and nanosecond laser pulses, have been covered.","PeriodicalId":250018,"journal":{"name":"Laser Technology and its Applications","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122347590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.79702
Zhen Yang, Xin Yu, Jiangbo Peng, Jianlong Zhang
Planar laser-induced fluorescence (PLIF) is a highly sensitive and space-time-resolved laser diagnostic technique. It is widely used in the diagnosis of combustion and flow fields to obtain the thermodynamic information of active components and interested molecules in flames. Nowadays, the PLIF technology is developing in two directions: high speed and quantification. In view of the high spatial and temporal resolution characteristics of PLIF technology that other laser diagnostics do not possess, this chapter will focus on the basic principle of laser-induced fluorescence and the current research status of quantitative PLIF technology. In addition, the advantages and disadvantages of various quantitative technologies of component concentration in flames based on laser-induced fluorescence technology are analyzed. At last, the latest works on the quantification of species concentration using planar laser-induced fluorescence in combustion are introduced. confirm the validity of the modified measurement equation, the effective peak absorption cross section of the band (0,0) and band (1,0) within the Q 1 (8) line for the OH radical is measured, respectively. The experimental results show that the OH effective peak absorption cross section of the Q 1 (8) line for band (0,0) turns out to be about 5.5 times higher than that of band (1,0), while the theoretical calculation given by the LIFBASE simulation is about 6 times. The experimental result has been proven to be in good agreement with the simulation results. and disadvantages of current quantitative PLIF technologies for species concentration measurements in flames are reviewed. the latest works on the quantification of species concentration using PLIF in combustion are introduced. a non-calibration quantitative PLIF technology, named bidirectional PLIF, which is independent of collisional quenching effect, has been introduced in detail. As the current measurement equation of effective peak absorption cross section provided by Versluis et al. is found to be not applicable to the case of weak absorption, experimental equation the two-dimensional spatial distributions of OH concentration its variations with the equivalence ratios investigated in the methane/air partially premixed flame. comparison between the experimental OH concentrations and the numerical simulation results under the equivalence ratios of 0.7 – indicates the OH concentration profiles measured by bidirectional in good agreement with the predictive values performed by
{"title":"Quantitative Planar Laser-Induced Fluorescence Technology","authors":"Zhen Yang, Xin Yu, Jiangbo Peng, Jianlong Zhang","doi":"10.5772/INTECHOPEN.79702","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.79702","url":null,"abstract":"Planar laser-induced fluorescence (PLIF) is a highly sensitive and space-time-resolved laser diagnostic technique. It is widely used in the diagnosis of combustion and flow fields to obtain the thermodynamic information of active components and interested molecules in flames. Nowadays, the PLIF technology is developing in two directions: high speed and quantification. In view of the high spatial and temporal resolution characteristics of PLIF technology that other laser diagnostics do not possess, this chapter will focus on the basic principle of laser-induced fluorescence and the current research status of quantitative PLIF technology. In addition, the advantages and disadvantages of various quantitative technologies of component concentration in flames based on laser-induced fluorescence technology are analyzed. At last, the latest works on the quantification of species concentration using planar laser-induced fluorescence in combustion are introduced. confirm the validity of the modified measurement equation, the effective peak absorption cross section of the band (0,0) and band (1,0) within the Q 1 (8) line for the OH radical is measured, respectively. The experimental results show that the OH effective peak absorption cross section of the Q 1 (8) line for band (0,0) turns out to be about 5.5 times higher than that of band (1,0), while the theoretical calculation given by the LIFBASE simulation is about 6 times. The experimental result has been proven to be in good agreement with the simulation results. and disadvantages of current quantitative PLIF technologies for species concentration measurements in flames are reviewed. the latest works on the quantification of species concentration using PLIF in combustion are introduced. a non-calibration quantitative PLIF technology, named bidirectional PLIF, which is independent of collisional quenching effect, has been introduced in detail. As the current measurement equation of effective peak absorption cross section provided by Versluis et al. is found to be not applicable to the case of weak absorption, experimental equation the two-dimensional spatial distributions of OH concentration its variations with the equivalence ratios investigated in the methane/air partially premixed flame. comparison between the experimental OH concentrations and the numerical simulation results under the equivalence ratios of 0.7 – indicates the OH concentration profiles measured by bidirectional in good agreement with the predictive values performed by","PeriodicalId":250018,"journal":{"name":"Laser Technology and its Applications","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123205872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-11-05DOI: 10.5772/INTECHOPEN.79703
M. Chi, O. B. Jensen, A. Hansen, P. Petersen
In this chapter, both blue and green high-power tunable diode laser systems based on GaN broad-area diode laser (BAL) in Littrow external cavity are demonstrated. For blue diode laser system, for high-power application, an output power around 530 mW over a 1.4 nm tunable range is obtained; for wide tunable range application, an output power around 80 mW over a 6.0 nm tunable range is obtained. For the green diode laser system, for high-power application, an output power around 480 mW with a tunable range of 2.1 nm is achieved; for wide tunable range application, an output power of 50 mW with a tunable range of 9.2 nm is achieved. The tuning range and output power optimization of an external-cavity diode laser system is investigated based on the experimental results obtained in the blue and green external-cavity GaN diode laser systems. The obtained results can be used as a guide for selecting gratings for external-cavity diode lasers for different requirements. The temporal dynamics of the green diode laser system is studied experimentally, and pulse package oscillation is observed, for the first time to our knowledge, in a BAL with an external-cavity grating feedback.
{"title":"Tunable High-Power External-Cavity GaN Diode Laser Systems in the Visible Spectral Range","authors":"M. Chi, O. B. Jensen, A. Hansen, P. Petersen","doi":"10.5772/INTECHOPEN.79703","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.79703","url":null,"abstract":"In this chapter, both blue and green high-power tunable diode laser systems based on GaN broad-area diode laser (BAL) in Littrow external cavity are demonstrated. For blue diode laser system, for high-power application, an output power around 530 mW over a 1.4 nm tunable range is obtained; for wide tunable range application, an output power around 80 mW over a 6.0 nm tunable range is obtained. For the green diode laser system, for high-power application, an output power around 480 mW with a tunable range of 2.1 nm is achieved; for wide tunable range application, an output power of 50 mW with a tunable range of 9.2 nm is achieved. The tuning range and output power optimization of an external-cavity diode laser system is investigated based on the experimental results obtained in the blue and green external-cavity GaN diode laser systems. The obtained results can be used as a guide for selecting gratings for external-cavity diode lasers for different requirements. The temporal dynamics of the green diode laser system is studied experimentally, and pulse package oscillation is observed, for the first time to our knowledge, in a BAL with an external-cavity grating feedback.","PeriodicalId":250018,"journal":{"name":"Laser Technology and its Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114249632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：