非临界相位匹配KTP光学参量振荡器的研究

利用1. 06μm激光脉冲泵浦非临界相位匹配(NCPM) KTP光学参量振荡器,获得中心波长1566nm的信号光输出。当泵浦光能量为100mJ时,输出信号光能量约为31. 9mJ ,相应的转换效率为30. 9% ,信号光脉冲宽度(10ns)比泵浦光脉冲宽度(30ns)小得多。当相位匹配角(内角)从90°到80°变化时,信号光调谐范围为1566～1596nm。     

近非临界相位匹配温度调谐MgO：LiNbO3OPO

通过对MgO:LiNbO3参量过程温度相位匹配及走离角，允许参量等运转参数的理论计算与分析，确定了晶体的切割角度θ=82℃，以近非临界相位匹配（NCPM）取代NCPM，将温度调节范围控制在较低的温度上，研制了532nm泵浦的MgO:LiNbO3温度调谐脉冲光学参数振荡器（OPO），在800～1700nm波段实现连续调谐输出。参量泵浦功率密度阈值为57.3MW/cm^2，泵浦能量约2倍阈值处，单谐振（SRO）参量转换效率为11%以上。     

高效率非临界相位匹配KTP光学参量振荡器

利用Nd∶YAG激光器1．064μm基频光抽运非临界相位匹配KTP（θ＝90°,＝0°）光学参量振荡器（OPO）,获得1．57μm相干光和高达64％的能量转换效率,分析了非临界相位匹配方式对KTP晶体定离效应和接收角的影响,并对OPO的阈值、效率、输出的光束质量进行了讨论。     

II类非临界相位匹配下近红外波段的差频产生器

报道了一个利用差频技术(DFG)产生近红外的装置。在此系统中1.064 μm半导体激光器作为信号光和0.56~0.71 μm染料激光器作为泵浦光,通过三硼酸锂晶体(LBO)在非线性相互作用下产生较高功率的可调谐近红外激光,其波长范围为1.4~2.2 μm。通过温度调谐非临界相位匹配(NCPM)技术,在II类相位匹配方式下实现差频发生器。其平均输出功率为35 mW以上。在1.6 μm近红外波段激光的转化效率可达到12.2%,具有宽调谐、窄线宽的特点,具有较为广泛的应用范围。     

1.57μ非临界相位匹配KTP参量振荡器

利用1.064μm激光泵浦非临界相位匹配（NCPM）KTP－OPO,获得了重复频率20Hz、输出能量115mJ的1.57μm激光输出。     

单轴晶非共线相位匹配研究

通过对单轴晶非共线相位匹配理论的分析 ,推导出相位失配梯度、接受容限角和有效非线性系数的精确表达式。以KDP晶体为例进行了非共线倍频的理论计算和实验测试。对实验结果的分析验证了非共线相位匹配理论分析和数值计算的正确性。     

高掺镁铌酸锂晶体的临界和非临界相位匹配条件

基于掺5%克分子MgO的LiNbO3晶体主折射率及温度系数的精确测量,计算了这种晶体的临界和非临界相位匹配条件,计算结果经实验验证,二者相当一致。     

GdYCOB的生长及非临界相位匹配三倍频性质

在大气气氛下生长了高光学质量的晶体Gd0.37Y0.63Ga4O(BO3)3(GdYCOB);测量了GdYCOB晶体的非晶界相位匹配三倍频转换效率,分析了GdYCOB晶体中色心等缺陷对三倍频转换效率的影响并提出了消除色心的途径。     

临界相位匹配砷酸钛氧钾光参量振荡器研究

为得到3~5 μm的中红外输出,对非共线泵浦砷酸钛氧钾（KTA）的临界相位匹配（θ=41.4°,φ=0°）光参量振荡器（OPO）进行了理论分析及实验研究。当以电光调Q的Nd∶YAG激光器泵浦KTA-OPO时,对应输出为3.75 μm的中红外激光,重复频率为1~25 Hz,最高输出单脉冲闲频光能量≥4.5 mJ。     

1.5 7μm非临界相位匹配KTP参量振荡器

利用1.064μm激光泵浦非临界相位匹配(NCPM)KTP-OPO,获得了重复频率20Hz、输出能量115mJ的1.57μm激光输出.     

Ⅰ类非临界相位匹配LBO腔外倍频660nm效率的研究

报道了利用LBO晶体对Nd:YAG纳秒激光器进行腔外倍频实验的研究结果,实验中LBO晶体采用Ⅰ类非临界相位匹配(NCPM),温度调谐。实验证明,采用LBO温度调谐方式具有倍频效率高、稳定性好、易于调节等优点,当匹配温度为8.4℃、基频光功率为1.3J时,获得了855mJ的660nm倍频光输出,最高转换效率达到66%,倍频光能量稳定度小于±3%。     

非临界相位匹配的人眼安全KTP光参量振荡器

报道了一台电光调Q,Nd∶YAG激光器泵浦的KTP脉冲光参量振荡器(OPO),获得了高单脉冲能量的人眼安全激光输出。KTP晶体按非临界相位匹配θ=90°和φ=0°进行切割,在Ⅱ类相位匹配(o→o+e)下,1.064μm的泵浦激光转换为人眼安全的1.57μm激光。KTP晶体的尺寸为10 mm×10 mm×20 mm,OPO谐振腔采用信号光单谐振的外腔结构,当二极管泵浦的Nd∶YAG激光器输出的1.064μm激光单脉冲能量为350 mJ,重复频率为10 Hz时,获得了单脉冲能量117 mJ的1.57μm激光输出,转换效率约为33.4%。     

BIBO Stability of D-Dimensional Filters

Consider the class of d-dimensional causal filters characterized by a d-variate rational function analytic on the polydisk . The BIBO stability of such filters has been the subject of much research over the past two decades. In this paper we analyze the BIBO stability of such functions and prove necessary and sufficient conditions for BIBO stability of a d-dimensional filter. In particular, we prove if a d-variate filter H(z) analytic on has a Fourier expansion that converges uniformly on the closure of , then H(z) is BIBO stable. This result proves a long standing conjecture set forth by Bose in [3].     

袋进袋出过滤器的特点与使用

介绍了袋进袋出过滤器的使用范围,基本组成以及特点,对比了袋进袋出过滤器与现有过滤设备在使用方面的优势。     

BIBO Stability of Continuous Time Systems

In this paper, the problems of the stability analysis and BIBO stabilization for the switched systems are considered. Applying a stabilizing local state feedback to each subsystem, the sufficient conditions of the asymptotically stable and BIBO stabilization for the switched systems are obtained by means of the method of Lyapunov function and the method of inequality analysis.     

A Note on BIBO Stability of Linear Discrete-Space Systems

The cornerstone of the theory of discrete-space single-input single-output linear systems is the idea that every such system has an input-output map H that can be represented by a convolution or the familiar generalization of a convolution. This thinking involves an oversight which, under some mild assumptions, was recently corrected by adding an additional term to the representation. Here we give a criterion for the bounded-input bounded-output stability of such systems.     

Picosecond ultraviolet optical parametric generation using atype-II phase-matched lithium triborate crystal for an injection seed ofVUV lasers

Output performance of a type-II phase-matched optical parametric generator using lithium triborate pumped at 266 nm is investigated. The optical parametric generator is designed to produce a narrow linewidth signal with good spatial quality at 326.7 nm for application to injection seeding of a vacuum ultraviolet (VUV) plasma laser. A linewidth of less than 0.1 nm and a beam divergence of 2× diffraction limit have been achieved without any diffractive optics     

Theory on phase-matched second-harmonic generation in biaxialplanar waveguides

A theoretical study on the optimization of second harmonic generation (SHG) in a planar waveguide in a biaxial nonlinear material is presented. Numerically computed curves show the dependence of the SHG efficiency on the condition of lateral focusing in the planar waveguide, of double refraction and of phase matching. The calculations take full account of double refraction and diffraction in the paraxial approximation in the planar guide. It is shown that in the absence of double refraction and under optimum focusing conditions the generated second harmonic power increases in proportion to L^3/2, where L is the length of the planar waveguide     

Insufficiencies of practical BIBO stable n-D systems

This paper is focused on analyzing the practical bounded input bounded output (BIBO) stability concept originally introduced by Agathoklis and Bruton with respect to its applicability in n-D signal processing applications. By comparing the frequency response expected on basis of the transfer function to the Fourier transform of the actually measured impulse response of exemplary systems it is shown that the concept of practical stability cannot be a general n-D stability criterion for systems, in particular for signal processing applications, if roots of the given transfer function are not guaranteed to be close to the respective n-D BIBO stability region.     

光子晶体光纤研究

光子晶体光纤以其灵活的结构设计和高非线性、平坦色散、高双折射等独特光学特性吸引了越来越多的关注.简单介绍了光子晶体光纤的分类,导光机理,详细讨论了其相关光学特性,最后介绍了光子晶体光纤的研究进展.