室温下连续波运行Tm:YAP泵浦的Ho:YAG激光器

我们报道了一种以二极管泵浦的 1.94 μm Tm:YAP激光器为泵浦源，常温下在2.1 μm连续运行的Ho:YAG激光器。最大输出功率1.5 W，相应斜率效率为17.9%，二极管到的转换效率为5.6%。

Judd-Ofelt analysis of spectra and experimental evaluation of laser performance of Tm3+ doped Lu2SiO5 crystal

This paper reports that the TM3+:Lu2SiO5 (Tm:LSO) crystal is grown by Czochralski technique. The room-temperature absorption spectra of Tm:LSO crystal are measured on a b-cut sample with 4 at.% thulium. According to the obtained Judd-Ofelt intensity parameters Omega(2)=9.3155 x 10(-20) cm(2), Omega(4)=8.4103 x 10(-20) cm(2), Omega(6)=1.5908 x 10(-20) cm(2), the fluorescence lifetime is calculated to be 2.03 ms for F-3(4) -> H-3(6) transition, and the integrated emission cross section is 5.81 x 10(-18) cm(2). Room-temperature laser action near 2 mu m under diode pumping is experimentally evaluated in Tm:LSO. An optical-optical conversion efficiency of 9.1% and a slope efficiency of 16.2% are obtained with continuous-wave maximum output power of 0.67 W. The emission wavelengths of Tm:LSO laser are centred around 2.06 mu m with spectral bandwidth of similar to 13.6 nm.

Comparison of Q-factors between TE and TM modes in 3-D microsquares by FDTD simulation

Mode characteristics of three-dimensional (3-D) microsquare resonators are investigated by finite-difference time-domain (FDTD) simulation for the transverse electric (TE)-like and the transverse magnetic (TM)-like modes. For a pillar microsquare with a side length of 2 pin in air, we have Q-factors about 5 X. 103 for TM-like modes at the wavelength of 1550 run, which are one order larger than those of TE-like modes, as vertical refractive index distribution is 3.17/3.4/3.17 and the cororresponding center layer thickness is 0.2 mu m. The mode field patterns show that TM-like modes have much weaker vertical radiation coupling loss than TE-like modes. TM-like modes can have high Q-factors in a microsquare with weak vertical field confinement.

Tb~(3+)在YAG中的发光及Tb~(3+)与Tm~(3 +)间的能量传递

采用溶胶 -凝胶方法合成了系列化合物 (Y1 -x- yTbxTmy) 3Al5O1 2 ,研究了Tb3+在该化合物中的发光及其浓度对发光性质的影响 ,以及Tb3+与Tm3+间的能量传递现象。

ELECTROCHEMICAL-BEHAVIOR OF BIS(2 /17-ARSENOTUNGSTATE) LANTHANATES AND THEIR ELECTROCATALYTIC REDUCTION FOR NITRITE

A series of new catalysts, K-14[Ln(As2W17O61)(2)]. xH(2)O (Ln = La, Pr, Sm, Eu, Gd, Tb, Dy, Tm and Yb) which can electrocatalyze reduction of nitrite are presented and their electrochemical behavior is described in this paper. Bis(2:17-arsenotungstate) lanthanates which are monovacant Dawson derivatives, exhibit two 2-electron and one 1-electron waves, attributed to electron addition and removal from the tungsten-oxide framework that comprises each anion structure. The formal potentials of redox couples are dependent on solution pH. Double-hump principle of formal potentials takes effect with increasing atomic number of lanthanide elements following their special electronic shell structure. The third waves of all the heteropolyanions have good electrocatalytic activities for nitrite reduction at pH 5.0.

蛋白质吸附和竞争吸附对ROS 17/2.8细胞粘附和生长的影响

细胞在材料表面的粘附是贴壁依赖型细胞生长的前提.本文以胶原和牛血清蛋白(BSA)为模型蛋白,研究了两者的吸附和竞争吸附对细胞粘附和生长的影响.

爆炸法制备Sm_2Fe_(17)N_y永磁体

本文介绍了爆炸烧结Sm_2Fe_(17)N_7永磁体的试验及其结果.试验时,在外加磁场下把Sm_2Fe__(17)N_y磁粉取向压制成形后装人金属包套内并抽真空,炸药装在包套外的纸筒内,雷管引爆炸药后,在爆轰压力作用下,磁粉被压实而烧结成磁体。试验结束后,取出磁体测量密度及磁性参数。烧结磁体密度在理论密度6的85％～96％范围内,磁能积大于88 KJ?m~(-3)。它表明,爆炸烧结工艺是制备Sm_2Fe_(17)Ny永磁体的有效工艺。

爆炸烧结Sm_2Fe_(17)N_y永磁体

<正> 自从1990年初Coey和孙弘发现R_2Fe_(17)N,化合物以来,人们对R_2Fe_(17)N,的内禀磁性和永磁性进行了大量的研究。Sm_2Fe_(17)N_y(y>2)由于具有优良的内禀磁性(居里

第17届国际气体放电会议(ICPIG-17)

<正> Ⅰ.概况 国际气体放电会议(ICPIG)每两年举行一次,主要交流在气体放电领域中有关的研究和发展情况。ICPIG-17由匈牙利Roland Etvs物理学会和物理中心研究所组织,匈牙利科学院赞助,在布达佩斯技术大学举行。会期1985年7月8—12日。到会代表360人,其中我国1人。邀请报告共31篇,其中11篇在大会上宣读。张贴论文共394篇。

Generation of 17-TW 23-fs pulses with a two-stage Ti : Sapphire amplifier at repetition rate 10 Hz

We have developed a two-stage Ti:sapphire amplifier system which can produce 17-TW/23-fs pulses at a repetition rate 10 MHz. A birefringent plate is used in the regenerative amplifier to alleviate gain narrowing, while an all-reflective cylindrical-mirror-based pulse stretcher and an acousto-optic programmable dispersive filter (AOPDF) are used to compensate for the higher order dispersion of the system.

Electromagnetic fields and transmission properties in tapered hollow metallic waveguides

We analyze the electromagnetic spatital distributions and address an important issue of the transmission properties of spherical transverse-electric (TE) and transverse-magnetic (TM) eigenmodes within a tapered hollow metallic waveguide in detail. Explicit analytical expressions for the spatital distributions of electromagnetic field components, attenuation constant, phase constant and wave impedance are derived. Accurate eigenvalues obtained numerically are used to study the dependences of the transmission properties on the taper angle, the mode as well as the length of the waveguide. It is shown that all modes run continuously from a propagating through a transition to an evanescent region and the value of the attenuation increases as the distance from the cone vertex and the cone angle decrease. A strict distinction between pure propagating and pure evanescent modes cannot be achieved. One mode after the other reaches cutoff in the tapered hollow metallic waveguide as the distance from the cone vertex desreases. (C) 2008 Optical Society of America

端面抽运的Tm:YAP薄片板条激光器的研究

2μm激光器由于其在遥感、雷达和医疗等领域具有重要的应用前景而受到越来越广泛的重视。Tm3+具有长的荧光寿命,且其吸收带与商用的激光二极管相匹配。YAP具有与YAG近似的机械和热性能,其双折射特性使得Tm:YAP激光器可以直接得到线偏振的激光输出,并且可以降低热退偏效应。795nm连续抽运光经透镜组耦合进薄片板条1mm×5mm晶体端面,采用平凹腔结构,分析比较了1%,4%和5%掺杂浓度的Tm:YAP的激光特性。