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61.
Recent developments in high power near-infrared super-continuum generation based on photonic crystal fiber 下载免费PDF全文
High power supercontinuum generation has witnessed rapid developments during the past few years. The mechanism and the latest achievements in high power supercontinuum generation are reviewed both for the continuous wave pump regime and the pulsed pump regime. The challenges in scaling the average power of supercontinuum generation are analyzed. Some of our works on high power supercontinuum generation are summarized, and perspectives for the future development are discussed. 相似文献
62.
通过已搭建好的激光超声检测实验平台,在保持相同激光脉冲能量和相同探测位置的条件下,重点研究了点光源与线光源产生的超声信号的特点和区别。研究了不同探测位置点光源与线光源激发出的超声信号幅值以及产生的超声信号波形。实验发现:在同一探测位置下,将点光源换成线光源后,产生的超声信号幅值由1.3 V提高到1.7 V,提高了0.4 V;在探测位置逐渐增大的情况下,点光源激发出超声信号幅值的衰减幅度为75.78%,而线光源激发出的超声信号幅值的衰减幅度为34.92%。结果表明,在功率密度相同的情况下,线光源产生的超声信号要比点光源产生的超声信号幅值提高40.86%,产生较强的表面波,提高了信噪比。 相似文献
63.
流动注射—氢化物发生—非色散原子荧光光谱法直接测定海水中的砷(Ⅲ)和砷( 总被引:7,自引:0,他引:7
用流动注射-氢化物发生-非色散原子荧光光谱法对海水中As(Ⅲ)和As(Ⅴ)的直接测定进行了研究,氢化物发生的最佳条件为:KHB4溶液浓度为5g.L^-1(含KOH5g.L^-1),流速10.0mL.min^-1;样品酸度为1.3mol.L^-1HCl,流速4.2mL.min^-1。对基体NaCl,MgCl2,CaCl2,Na2SO4以及微量共存金属离子(Cd,Zn,Pd,Cu)的干扰实验结果表明,基体和微量共存金属离子对As(Ⅲ)的测定没有干扰。样品中As(Ⅴ)的测定用硫脲进行预还原,通过总量和As(Ⅲ)的含量的差减得到As(Ⅴ)含量,在优化实验条件下下测量方法的检出限(3σ)为0.08ng.mL^-1;7次测定的相对标准偏差为0.48%-1.30%(8.0ng.mL^-1标准溶液)。标准曲线和标准加入法对海水 相似文献
64.
对水-二甲基亚砜二元混合溶液质量分数和温度与折射率的关系进行了理论和实验研究,对几种经典模型的拟合结果进行了比较,给出了适合水-二甲基亚砜混合溶液的经验公式。对水性金溶胶-二甲基亚砜混合溶液质量分数和温度对局域表面等离子体共振峰值波长的影响进行了理论和实验研究,结果表明:水性金溶胶-二甲基亚砜混合溶液质量分数对共振峰值波长的调节有较好的线性关系和较大的调节范围,当温度从20 ℃增大到60 ℃,混合溶液金溶胶的共振峰值波长增加了1367 pm,温度敏感度为34 pm/K,在0%~100%的质量分数范围内,混合溶液金溶胶的共振峰值波长平均产生8.5103 pm的增长。 相似文献
65.
Coherent Beam Combination of Two Polarization Maintaining Ytterbium Fibre Amplifiers 总被引:10,自引:0,他引:10 下载免费PDF全文
We investigate coherent beam combination of fibre laser beams by phase locking. Phase noise of a polarization maintaining ytterbium fibre amplifier is inspected with a fibre interferometer. In a feed back control loop, two fibre polarization maintaining ytterbium amplifiers are phase locked and coherent combined when the phase noise is properly controlled by a LiNO3 phase modulator. 相似文献
66.
We experimentally investigate the spectral details of a picosecond supercontinuum pumped at 1064 nm and seeded by a weak continuous wave (~20000 times weaker than the pulse peak power) at several power levels in photonic crystal fibers. Seeding at different wavelengths leads to different spectral details and the effects to the bandwidth of supercontinuum are also distinct. Spectra can be widened when seeded by a continuous wave at 1070 nm and narrowed by ~100 nm when seeded at 1080 nm. The influence is enhanced by increasing the average seeded power. 相似文献
67.
A high-power all-fiber single-frequency polarization-maintained(PM)laser operating at 1 083 nm is demonstrated using a master oscillator power amplifier(MOPA)structure.The seed source of this MOPA laser system is an in-house-built ring-cavity fiber oscillator.Four-stage amplification configuration is employed, in which the maximal output power of the main amplifier is 90.4 W,corresponding to a conversion efficiency of 72.5%.The polarization extinction ratio of the output light is 13 dB.The amplified spontaneous emission is suppressed by a factor of over 25 dB,and no stimulated Brillouin scattering effect is observed when a large-mode-area and high absorption coefficient PM gain fiber is employed. 相似文献
68.
超连续谱的相干性直接影响到很多光学测量器件的分辨率及准确性, 如何获得高相干度的超连续谱是当前非线性光学领域的研究热点之一. 本文首先分析超连续谱产生的机理, 认为调制不稳现象是降低超连续谱相干性的重要因素. 因此抑制调制不稳定性, 利用其他非线性效应(如自相位调制)是得到高相干性超连续谱的有效方法. 最后设计了一种全波段正常色散光子晶体光纤,仿真结果表明, 在脉宽400 fs无啁啾高斯脉冲抽运, 50 cm长该光子晶体光纤的条件下, 产生的超连续谱具有在相对功率大于-80 dB的全波段高度相干的特性. 相似文献
69.
垃圾渗滤液中 As和 Hg的流动注射蒸气发生非色散原子荧光光谱法测定 总被引:5,自引:0,他引:5
建立了垃圾渗滤液中As和Hg的流动注射蒸气发生-非色散原子荧光光谱的测定方法。在低温下采用硝酸-过氧化氢体系消化处理样品;硫脲-抗坏血酸将As(V)还原后测定样品中的总As;Hg的测定用Hg蒸气发生原子荧光光谱法。对测量条件进行了优化,在优化实验条件下测得As和Hg的检出限分别为0.08和0.007μg/L,10次测定的相对标准偏差分别为0.48%和0.85%(对8.0μg/L As和1.0μg/L Hg标准溶液)。共存的NaCI、MgCI2、CaCI2、Na2SO4、NaF以及微量共存金属离子(Cd、Se、Zn、Pb、Cu、Fe、Mn、AI)对As和Hg的测定没有干扰。用标准校正曲线和标准加入法对样品测定结果进行了比较,实验结果表明二者吻合较好。 相似文献
70.