光子晶体光纤及其应用

光子晶体作为一种新兴的材料 ,将会对整个光子学和光子产业领域产生深远的影响 ,而其最重要的应用之一———光子晶体光纤已经在很多科研技术领域得到了应用 .文章综述了光子晶体光纤的研究进展 ,给出其分类 ,并重点介绍了光子晶体光纤在超短脉冲、光频测量、光纤通信等科研领域的重要应用以及未来的发展前景     

KDP晶体Sol—Gel膜技术

Sol—Gel法制备的化学膜具有较高的抗激光损伤阈值、很好的增透效果以及大面积成膜均匀性，因此可提高高功率激光器的输出能量，以满足ICF相关实验需要。尤其是针对KDP晶体吸湿性强、对温度变化敏感、易脆裂等苛刻性质，通过化学涂膜的途径解决晶体的防潮和增透问题具有极大的优越性。KDP晶体上涂制常规防潮膜和减反膜的研究已经进行了数年，其研究成果已在“神光”-Ⅱ上得到应用。但是尚有不少技术指标需要改善，包括膜层损伤阈值的提高、膜层的疏水性能、耐擦刮性能、耐环境污染性能以及大尺寸的光学元件的涂膜工程化（包括设备、工艺、涂膜质量的稳定性等）等方面，都需要进一步的研究，以满足“神光”-Ⅲ的工程需求。     

H^＋注入锗酸铋晶体表面层的性质

Ｈ＾＋注入锗酸铋（Ｂｉ４Ｇｅ３Ｏ１２或ＢＧＯ）晶体引起某些效应，如辐射损伤，光学吸收和近表层区域的晶体分解。经Ｈ＾＋注入后，ＢＧＯ晶体的颜色变成棕色，但实验中证实不了该变化是由色心的产生所引起。此外，实验中也示观察到Ｈ＾＋注入ＢＧＯ晶体中有离子束诱发的光学活性变化。可见在注入过程中，未发生从Ｂｉ４Ｇｅ３Ｏ１２转变到Ｂｉ１２ＧｅＯ２０的结构相变，由此预见，注入过程中可能发生离子束引起的晶体分解。Ｈ＾     

Interface Instability of Diamond Crystals at High Temperature and High Pressure

Diamond growth instability at high temperature and high pressure (HPHT) has been elucidated by observing the cellular interface in diamond crystals.The HPHT diamond crystals grow layer by layer from solution of carbon in the molten catalyst.In the growth of any other cyrstals from solution,the growth interface is not stable and should be of the greatest significance to understand further the diamond growth mechanism.During the diamond growth,the carbon atoms are delivered to the growing diamond crystal by diffusion through a diamond crystal-solution boundary layer.In front of the boundary layer,there is a narrow constitutional supercooling zone related to the solubility difference between diamond and graphite in the molten catalyst.The diamond growth stability is broken,and the flat or planar growth interface transforms into a cellular interface due to the light supercooling.The phenomenon of solute trails in the diamonds was observed,the formation of solute trails was closely associated with the cellular interface.     

Yb∶YAG晶体的晶胞参量及Yb~(3+)分凝系数的研究

应用提拉法生长出不同Yb3+ 浓度的Yb3xY3( 1-x) Al5O12 晶体 Yb3+ 离子的分凝系数 1是 1 .0 8±0 .0 1 ,与Yb3+ 离子掺杂浓度无关 研究了Yb3xY3( 1-x) Al5O12 晶体的晶胞参量 ,推导出联系晶胞参量、密度与Yb3+ 离子掺杂浓度的关系方程式     

质量数A≈125的热核GDR特性的研究

简单介绍了利用LNS的回旋加速器产生的^116。Sn束轰击^12C和^24Mg靶的实验装置以及实验过程．该实验通过MEDEA探测器测量了由全熔合与非全熔合反应产生的较低激发能区(160-300MeV)质量数A≈125的热核的巨偶极共振特性，比较了不同靶子、不同束流能量时巨偶极共振的7产额的变化．The experiment was carried out at the National Laboratory of South in Italy using~(116)Sn beam of 17 and 23 MeV/u delivered from the Superconducting Cyclotron impinging on~(12)C and~(24)Mg targets. The hot nuclei have been formed by complete and incomplete fusion reactions. The characteristics of the giant dipole resonance(GDR) in hot nuclei of mass A≈125 at lower excitation energies between 160 and 300 MeV have been measured with the multi element detector array (MEDEA) detector. A comparison of GDR ...     

A Photonic Bandgap Filter Using Metallic Hilbert Curves

We theoretically suggest that a metallic plate with Hilbert curves can possesses multiple resonances in a linear scale, leading to multiple stop bands and pass bands for electromagnetic waves over a wide frequency range.The forward transmission from a line source nearby a small plate covered by four cells with Hilbert curves is checked by a probe at the far field, the results agree well with the multiple resonance frequencies calculated by the plane wave incidence under a periodic boundary condition, the return loss spectra show that radiations of a line antenna working at 4.5 GHz can be greatly enhanced, which results from the interaction of the antenna and the subwavelength metallic plate. This kind of metallic pattern is very practical in multi-frequency functioned wave devices with sub-wavelength sizes.     

Bessel-Modal Method for Finite-Height Two-Dimensional Photonic Crystal

By applying the dyadic Green function, the dispersion relation of two-dimensional photonic crystal can be expressed as the cylindrical wave expansions of eigenmodes. With the aid of Green‘s theorem, the plane-wave coefficients of eigenmodes are reconstructed and employed to formulate the scattering matrix of finite-height twodimensional photonic crystal. These operations make the convergence rate very rapid, and reduce the dimension of the scattering matrix. As a demonstration, we present the transmission and electromagnetic field distributions for an InGaAsIn photonic crystal, and investigate their convergence.