Chemical mechanical polishing （CMP） was used to polish Lithium triborate （LiB3O5 or LBO） crystal. Taguchi method was applied for optimization of the polishing parameters. Material removal rate （MRR） and surface ...Chemical mechanical polishing （CMP） was used to polish Lithium triborate （LiB3O5 or LBO） crystal. Taguchi method was applied for optimization of the polishing parameters. Material removal rate （MRR） and surface roughness are considered as criteria for the optimization. The polishing pressure, the abrasive concentration and the table velocity are important parameters which influence MRR and surface roughness in CMP of LBO crystal. Experiment results indicate that for MRR the polishing pressure is the most significant polishing parameter followed by table velocity; while for the surface roughness, the abrasive concentration is the most important one. For high MRR in CMP of LBO ctystal the optimal conditions are： pressure 620 g/cm^2, concentration 5.0 wt pct, and velocity 60 r/min, respectively. For the best surface roughness the optimal conditions are： pressure 416 g/cm^2, concentration 5.0 wt pct, and velocity 40 r/min, respectively. The contributions of individual parameters for MRR and surface roughness were obtained.展开更多
Frequency-doubled antireflection coatings simultaneously effective at 1064 nm and 532 nm were deposited on the lithium triborate （LiB3O5 or LBO） crystals using the electron beam evaporation method. Comparing with th...Frequency-doubled antireflection coatings simultaneously effective at 1064 nm and 532 nm were deposited on the lithium triborate （LiB3O5 or LBO） crystals using the electron beam evaporation method. Comparing with the sample without buffer layer, it is found that the adhesion of the sample with buffer layer of SiO2 between coating and LBO substrate is improved significantly from 137.4 mN to greater than 200 mN. And the laser-induced damage threshold is increased by 20% from 15.1 J/cm^2 to 18.6 J/cm^2. The strengthening mechanism of adhesion of the buffer layer of SiO2 is discussed by considering full plastic indentation and shear theory.展开更多
A petawatt facility fully based on noncollinear optical parametric chirped pulse amplification(NOPCPA)technology,Vulcan OPPEL(Vulcan OPCPA PEtawatt Laser),is presented.This system will be coupled with the existing hyb...A petawatt facility fully based on noncollinear optical parametric chirped pulse amplification(NOPCPA)technology,Vulcan OPPEL(Vulcan OPCPA PEtawatt Laser),is presented.This system will be coupled with the existing hybridCPA/OPCPA VULCAN laser system(500 J,500 fs beamline;250 J,ns regime beamline)based on Nd:glass amplification.Its pulse duration(20 times shorter)combined with the system design will allow the auxiliary beamline and its secondary sources to be used as probe beams for longer pulses and their interactions with targets.The newly designed system will be mainly dedicated to electron beam generation,but could also be used to perform a variety of particle acceleration and optical radiation detection experimental campaigns.In this communication,we present the entire beamline design discussing the technology choices and the design supported by extensive simulations for each system section.Finally,we present experimental results and details of our commissioned NOPCPA picosecond front end,delivering 1.5 mJ,~180 nm(1/e^(2))of bandwidth compressed to sub-15 fs.展开更多
基金supported by the National Natural Science Foundation of China(No.50675104 and 50905086)Six High Talent Fund of Jiangsu Province(No.06-D-024)Talent Fund of NUAA(No.S0782-052)
文摘Chemical mechanical polishing （CMP） was used to polish Lithium triborate （LiB3O5 or LBO） crystal. Taguchi method was applied for optimization of the polishing parameters. Material removal rate （MRR） and surface roughness are considered as criteria for the optimization. The polishing pressure, the abrasive concentration and the table velocity are important parameters which influence MRR and surface roughness in CMP of LBO crystal. Experiment results indicate that for MRR the polishing pressure is the most significant polishing parameter followed by table velocity; while for the surface roughness, the abrasive concentration is the most important one. For high MRR in CMP of LBO ctystal the optimal conditions are： pressure 620 g/cm^2, concentration 5.0 wt pct, and velocity 60 r/min, respectively. For the best surface roughness the optimal conditions are： pressure 416 g/cm^2, concentration 5.0 wt pct, and velocity 40 r/min, respectively. The contributions of individual parameters for MRR and surface roughness were obtained.
基金Fundeded by the Doctorial Start-up Fund of the Department of Science and Technology of Liaoning Province(20081030)S&T Plan Project of the Educational Department of Liaoning Province(2008224)
文摘Frequency-doubled antireflection coatings simultaneously effective at 1064 nm and 532 nm were deposited on the lithium triborate （LiB3O5 or LBO） crystals using the electron beam evaporation method. Comparing with the sample without buffer layer, it is found that the adhesion of the sample with buffer layer of SiO2 between coating and LBO substrate is improved significantly from 137.4 mN to greater than 200 mN. And the laser-induced damage threshold is increased by 20% from 15.1 J/cm^2 to 18.6 J/cm^2. The strengthening mechanism of adhesion of the buffer layer of SiO2 is discussed by considering full plastic indentation and shear theory.
基金financial support of the European Union’s Horizon 2020 research and innovation programme under grant agreement No.654148(Laserlab Europe)the Euratom research and training program 2014–2018 under grant agreement No.633053+1 种基金the Fundacao para a Ciencia e a Tecnologia(FCT,Lisboa)under grants No.PD/BD/114327/2016framework of the Advanced Program in Plasma Science and Engineering(APPLAuSE,sponsored by FCT under grant No.PD/00505/2012)at Instituto Superior Tecnico(IST)。
文摘A petawatt facility fully based on noncollinear optical parametric chirped pulse amplification(NOPCPA)technology,Vulcan OPPEL(Vulcan OPCPA PEtawatt Laser),is presented.This system will be coupled with the existing hybridCPA/OPCPA VULCAN laser system(500 J,500 fs beamline;250 J,ns regime beamline)based on Nd:glass amplification.Its pulse duration(20 times shorter)combined with the system design will allow the auxiliary beamline and its secondary sources to be used as probe beams for longer pulses and their interactions with targets.The newly designed system will be mainly dedicated to electron beam generation,but could also be used to perform a variety of particle acceleration and optical radiation detection experimental campaigns.In this communication,we present the entire beamline design discussing the technology choices and the design supported by extensive simulations for each system section.Finally,we present experimental results and details of our commissioned NOPCPA picosecond front end,delivering 1.5 mJ,~180 nm(1/e^(2))of bandwidth compressed to sub-15 fs.
