共查询到18条相似文献,搜索用时 109 毫秒
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基于非线性光学晶体的混频理论,利用CsLiB6O10(CLBO)晶体和K2Al2B2O7(KABO)晶体获得了紫外相干光源,详细比较了两种晶体在Ⅰ类相位匹配下的混频性能,包括混频相位匹配角、有效非线性系数、光波走离角、允许角和允许波长等参量.结果表明,KABO晶体比CLBO晶体的有效非线性系数小,其它性能均与CLBO晶体接近.这对于两种晶体用于产生紫外激光的实验研究提供了重要的理论依据.考虑到KABO晶体较好的物化性质以及不潮解这一显著特征,KABO晶体可能是最有希望实现实用化的紫外混频晶体. 相似文献
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紫外晶体CsLiB6O10混频允许参量范围的数值分析 总被引:3,自引:1,他引:2
模拟计算了CLBO晶体混频的相位匹配角、有效非线性系数、走离角、允许角和允许波长的理论曲线。通过与BBO晶体的比较,得到了CLBO晶体的混频作用具有走离角小、允许参量范围宽的结论。 相似文献
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CsLiB6O10晶体光学参变振荡器的光学特性 总被引:3,自引:0,他引:3
根据三波耦合过程中的能量和动量守恒、晶体的塞耳迈耶尔色散方程,通过数值模拟计算了213nm作CLBO光学参变振荡抽运源时,分别得到了在Ⅰ类和Ⅱ类相位匹配时参量光调谐范围为237~289nm、807~2793nm和404~2800nm。获得了在Ⅰ类匹配时的单谐振或双谐振腔的CLBO光学参变振荡转换效率都大于同等条件下的BBO光学参变振荡,Ⅱ类匹配时,CLBO晶体的转换效率略小于BBO晶体,但是CLBO光学参变振荡转换效率的最大值较BBO光学参变振荡出现于更短的紫外波段。从理论上证明了CLBO晶体是优质的深紫外透光波段非线性光学晶体。 相似文献
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La2CaB10O19(LCB)为可通过Nd∶YAG激光三倍频产生355 nm紫外激光的非线性光学晶体,其光学性能可与商用化的LiB 3O 5(LBO)晶体媲美,但抗潮解特性优势明显。本文对用LCB晶体实现355 nm紫外激光输出的三倍频产生过程进行了优化设计,利用走离补偿方法来提高激光输出转换效率。通过在光路中加入沿θ=45°方向切割、厚度为1.2 mm的方解石晶体走离补偿片,在脉冲宽度为60 ns、重复频率10 kHz的激光参数下实现355 nm输出功率由12 W提升至20 W;在脉冲宽度为25 ps、重复频率为10 Hz的激光参数下355 nm转换效率由28.3%提升至35.2%。 相似文献
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群速失配对CsLiB6O10晶体谐波脉冲展宽的影响 总被引:1,自引:2,他引:1
对超短强激光脉冲在CsLiB6O10晶体中的群速失配进行了理论分析,采用傅里叶变换法推导超短脉冲二次谐波的耦合波方程。在Ⅰ类相位匹配下数值计算了脉冲宽度50fs的基波532nm,在CsLiB6O10晶体长度为0.5mm时产生二次谐波(266nm)的群速延迟量约100fs,并且随着晶体长度的增长,二次谐波的脉冲宽度几乎线性展宽。并得到了群速失配量△β1^(2)226.243fs/mm,低阶和二阶群速色散系数分别为β2^(3)=210.120fs^2/mm,β2^(3)=65.587fs^3/mm。其结果表明由于群速延迟和群速色散导致了谐波脉宽展宽和形变。 相似文献
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介绍了一种基于新型非线性晶体Ba1-xB2-y-zO4SixAlyGaz 的可调谐深紫外飞秒激光光源. 从理论上分析了基频光和倍频光在通过非线性晶体时所造成的空间走离和群速度失配, 为了补偿空间走离以及波长调谐过程中晶体折射造成的光束偏离现象, 将两块相同的倍频晶体成镜像放置来产生二次谐波. 并调节延迟线的长度来补偿基频光和倍频光之间的群速度失配, 从而提高和频转换效率. 然后通过和频方式进行三倍频和四倍频来突破晶体相位匹配条件的限制, 产生了波长低于200 nm的深紫外飞秒激光. 利用钛宝石激光器提供基频光光源, 最终在250–300 nm, 192.5–210 nm 范围内获得了高重频、可调谐超短脉冲紫外和深紫外激光. 并在基频光波长为800 nm时, 得到的二倍频、三倍频和四倍频的功率分别为1.28 W, 194 mW和5.8 mW, 相对于前一级的转换效率依次为46.14%, 15.16%和3%. 采用互相关法测量得到266.7 nm紫外激光的脉冲宽度约为640.4 fs. 相似文献
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The third harmonic generation(THG) of a linear cavity Ti:sapphire regenerative amplifier by use of a K_3B_6O_(10)Cl(KBOC) crystal is studied for the first time. Output power up to 5.9 mW is obtained at a central wavelength of 263 nm,corresponding to a conversion efficiency of 4.5% to the second harmonic power. Our results show a tremendous potential for nonlinear frequency conversion into the deep ultraviolet range with the new crystal and the output laser power can be further improved. 相似文献
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K_3B_6O_(10)Cl(KBOC), a new nonlinear optical crystal, shows potential advantages for the generation of deep ultraviolet(UV) light compared with other borate crystals. In this paper we study for the first time the second harmonic generation(SHG) of a femtosecond Ti:sapphire amplifier with this crystal. Laser power is obtained to be as high as 220 m W at the central wavelength of 396 nm with a 1-mm-long crystal, and the maximum SHG conversion efficiency reaches 39.3%. The typical pulse duration is 83 fs. The results show that second harmonic(SH) conversion efficiency has the room to be further improved and that the new nonlinear crystal is very suited to generate the high efficiency deep ultraviolet laser radiation below 266 nm. 相似文献
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本文研究了在B_2O_3—Al_2O_3—PbO玻璃中引入SiO_2、Sb_2O_3、Ga_2O_3后,TF光学玻璃化学稳定性及相对部分色散P_(g·F)。论证了B_2O_3—Al_2O_3—PbO光学玻璃光学性质、化学组成和结构关系。TF光学玻璃在3.51铂坩埚熔制。 相似文献
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Raman spectra of a vanadoborate(Na3VO2B6O11) crystal from room temperature up to the melting point have been recorded. The main internal vibrational modes of the crystal have been assigned. It was found that all the Raman bands exhibit decreases in frequency and the widths of the Raman bands increase with the increase of temperature. However,no phase transition was observed under 525℃. The micro-structure of its melt was studied by quantum chemistry ab initio calculation. The continuous three-dimensional network of the crystal collapsed and transformed into VO_4 and VBO_6 clusters during the melting process with an isomerization reaction from four-coordinated boron to a three-coordinated species. 相似文献
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根据波耦合中的能量动量守恒和色散方程,数值模拟计算了CsLiB6O10晶体在II类相位匹配下的倍频和混频产生的允许参量理论曲线.通过与β-BaB2O4晶体的比较,得到了CsLiB6O10晶体的谐波具有走离角小、允许参量范围宽的结果. 相似文献
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Deep-ultraviolet surface plasmon resonance of Al and Al_(core)/Al_2O_(3shell) nanosphere dimers for surface-enhanced spectroscopy 下载免费PDF全文
The localized surface plasmon resonance properties of Al and Alcore/Al2O3 shell nanosphere dimers with Al and Al core nanosphere radii of 20 nm and Al2O3 shell of 2 nm in the deep-ultraviolet region have been studied using the finite difference time domain method. The extinction spectra and the electric field distribution profiles of the two dimers for various gap distances between two individual nanospheres are compared with those of the corresponding monomers to reveal the extent of plasmon coupling. It is found that with the interparticle distance decreasing, a strong plasmon coupling between two Al or Alcore/Al2O3 shell nanospheres is observed accompanied by a significant red shift in the extinction spectra at the parallel polarization direction of the incident light related to the dimer axis, while for the case of the perpendicular polarization direction, a weak plasmon coupling arises characterized by a slight blue shift in the extinction spectra. The electric field distribution profiles show that benefiting from the dielectric Al2O3 shell, the gap distance of Alcore/Al2O3 shell nanosphere dimers can be tailored to < 1 nm scale and results in a very high electric field enhancement. The estimated surface-enhanced Raman scattering enhancement factors suggests that the Alcore/Al2O3 shell nanosphere dimers with the gap of < 1 nm gave rise to an enhancement as high as 8.1 × 107 for interparticle gap = 0.5 nm. Our studies reveal that the Alcore/Al2O3 shell nanosphere dimers may be promising substrates for surface-enhanced spectroscopy in the deep-ultraviolet region. 相似文献
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CHENG Zhenxiang ZHANG Shujun WANG Yan HAN Jianru CHEN Huanchu 《Chinese Journal of Lasers》2001,10(5):383-386
1 Introduction Theopticalcharacteristicsofglasses,suchasglasstransparencyandtheircapabilitytoacceptrareearthionsastheluminescentcenters ,areessentialfortheiruseinglasslasertechnology .Duringthelastfewyears,alargevarietyofinorganic glasseshavebeendevelop… 相似文献
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Performance and reliability improvement of La_2O_3/Al_2O_3 nanolaminates using ultraviolet ozone post treatment 下载免费PDF全文
La-based binary or ternary compounds have recently attracted a great deal of attention as a potential candidate to replace the currently used Hf-based dielectrics in future transistor and capacitor devices for sub-22 generation. However, the hygroscopic nature of La2O3 hampers its application as dielectrics in electron devices. To cope with this challenge, ultraviolet (UV) ozone post treatment is proposed to suppress the moisture absorption in the H2O-based atomic layer deposition (ALD) La2O3/Al2O3 nanolaminates which is related to the residual hydroxyl/hydrogen groups after annealing. The x-ray photoelectron spectroscopy (XPS) and conductive atomic force microscopy (AFM) results indicate that the moisture absorption of the H2O-based ALD La2O3/Al2O3 nanolaminates is efficiently suppressed after 600 ℃ annealing, and the electrical characteristics are greatly improved. 相似文献