共查询到20条相似文献,搜索用时 46 毫秒
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LiNbO3波导中切伦科夫辐射型的倍频 总被引:1,自引:1,他引:0
对条波导中切伦科夫辐射型的倍频作了简要分析,着重分析了产生切伦科夫辐射倍频的,工从实验上实现了条波导中1.06μm红外光到0.531m绿光的倍频辐射,转换效率为的0.9%,对应的输入光功率为10mW。 相似文献
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各向异性晶体波导的倍频理论和实验研究 总被引:1,自引:2,他引:1
在波导耦合理论基础上,根据平面波导和通道波导的具体结构,分别推导了二种波导的倍频转换效率表达式,讨论了各种因素对倍频效率的影响,并采用离子法制备掺氧化镁铌酸锂和钽酸锂波导,测试和分析了它们的倍频性能,讨论了比较了平面和通道波道的特点。 相似文献
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用标量有限元方法计算了周期性极化的铌酸锂光波导中模折射率和模场分布,并在计算中引入铌酸锂晶体折射率与温度变化的关系,分析了准位相匹配铌酸锂波导倍频效率与极化反转光栅周期、基频光波长、波导器件温度等关系.理论分析与实验结果符合得很好.在此基础上,分析了波导制作参数与倍频效率、光栅周期与晶体温度,以及温度带宽与光栅通光方向长度等关系,进而对铌酸锂波导倍频器件进行优化设计.
关键词:
铌酸锂
光波导
准位相匹配
有限元 相似文献
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In this paper, propagation and polarization characteristics of optical waves in arbitrary directions in a biaxial crystal are analyzed, and universal relationships of refractive index dependence on their propagation directions and the principal refractive indices for two perpendicular polarization waves propagating in arbitrarily directions are derived from indicatrix equation. By using these relationships, methods of collinear phase matching (PM) of SHG are developed, and general expressions of the collinear PM angle dependent of the principal indices are given for SHG in arbitrarily directions. The expressions may be used to make optimization design of PM by computer for the SHG and to select optimum PM direction and to raise the SHG conversion efficiencies. 相似文献
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YANG Shengli CHEN Mouzhi 《Chinese Journal of Lasers》2002,11(1):23-26
1 Introduction Severalbiaxialcrystals ,suchasKTP ,LBO ,havesomeexcellentproperties,suchaslargenonlinear (NL )coefficients,widewavelengthrangesoftransmission ,andeasilygrowinglargesizecrystalwithhighquality .Thebiaxialcrystalshavebeenextensivelyusedinlaserfr… 相似文献
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General expression for the energy loss in Cerenkov radiation due to a charged particle possessing anomalous magnetic moment
is obtained. The expressions include the spin-polarization of the particles. The contribution to the radiation due to anomalous
magnetic moment is found to be small as compared to that due to charge. The interference term of charge and anomalous magnetic
moment gives better contribution as compared to the term containing only anomalous magnetic moment. Polarization of the radiation
as dependent on polarization of beam of particles is studied. The radiation has a dominant nature of linear polarization with
small quantum corrections. The spin-flip also gives quantum correction to strong linear polarization and at threshold when
phase velocity equals velocity of the particle. 相似文献
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针对现有核素治疗中内照射剂量测量缺乏简单、高效方法的问题,基于内照射剂量与切伦科夫辐射之间的关系,提出一种基于切伦科夫辐射的核素治疗内照射剂量测量的新方法。利用蒙特卡罗计算程序Geant4,模拟放射性核素131I在水体模型和甲状腺模型中产生切伦科夫辐射与剂量沉积的分布情况,并定量分析切伦科夫光子数与剂量之间的关系。计算结果表明:在水体模的半径方向上切伦科夫光子数与剂量之间有着相同的变化趋势,且两者有着相同的二维分布规律;核素131I在介质中产生的切伦科夫光子数与剂量两者之间存在一定的线性关系,且这种线性关系与核素的分布情况无关。研究结果证实,将这种放射性核素在介质中产生的切伦科夫辐射应用于内照射剂量学具有非常大的研究潜力和价值。 相似文献
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基于导带电子密度和材料的有效介电函数的表达式,推导了KTP晶体对532 nm光波的吸收系数. 对比研究了不同峰值功率密度和重复频率下KTP晶体的导带电子密度和532 nm吸收系数的演化规律,以及倍频转换效率的演化规律. 结果表明,随着导带电子密度的增加,KTP晶体532 nm吸收系数随之增加,其倍频转换效率随之减小;当基频光入射功率密度一定时,不同重复频率脉冲作用引起的导带电子密度存在积累效应,导致KTP晶体532 nm透过率及倍频转换效率均随着作用时间的增加呈指数形式变化,随着脉冲重复频率的增加其积累效果更加明显,但随着作用时间的增加,导带电子密度、吸收系数均趋于同一稳定值.
关键词:
KTP晶体
灰迹
倍频转换效率 相似文献
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Powerful millimeter-wave generators based on the stimulated Cerenkov radiation of relativistic electron beams 总被引:2,自引:0,他引:2
V. L. Bratman G. G. Denisov B. D. Kol'chugin S. D. Korovin G. D. Polevin V. V. Rostov 《International Journal of Infrared and Millimeter Waves》1984,5(9):1311-1332
Effective relativistic Cerenkoy generators of various types were studied experimentally: orotrons, surface wave oscillators, and Smith-Purcell free-electron masers that were first realized. Single-mode generation was obtained in multimode systems using electrodynamic and electron methods of mode selection. The power obtained in this regime was 100 MW at 8.6 mm with the efficiency 10%, 50 MW at 5.5 mm with the efficiency 5%, and 8 MW at 2.4 mm with the efficiency 3%. In a multimode regime the power of 0.5 MW was obtained at 0.9 mm. The study of the dependence of the generation power on the value of the focusing magnetic field revealed the presence of zones of cyclotron power absorption, that were earlier observed in centimeter-wave generators. 相似文献