神光Ⅱ升级装置终端光学组件的排布设计

设计高功率激光装置靶场终端光学组件(FOA)时考虑的重要因素是鬼像对光学元件的破坏。由于神光Ⅱ升级装置(SG-Ⅱ-U)的输出能量高、靶场空间小、鬼像分布情况复杂,导致了终端光学组件的设计难度很高。用自主研发的鬼像控制设计软件对神光Ⅱ升级装置靶场终端光学组件排布进行设计,给出了进行鬼像控制设计时需考虑的设计因素,并对比研究了两种靶场终端光学组件设计方案的优缺点,最后结合神光Ⅱ升级装置的特点,优化设计出神光Ⅱ升级装置靶场终端光学组件的最终排布方案。

A large-area photolithography technique based on surface plasmons leakage modes

An atomic force microscope (AFM) assisted surface plasmons leakage radiation photolithography technique has been numerically demonstrated by using two-dimensional finite-difference time-domain (2D-FDTD) method. With the aid of a metallic AFM tip, particular characteristic of the Kretstchmann configuration to excite surface plasmons (SPs) is utilized to achieve large-area patterns with high spatial resolution and contrast, the photoresist could be exposed with low power laser due to the remarkable local field enhancement at the metal/dielectric interface and the resonant localized SPs modes near the tip. Good tolerance on the film thickness and incident angle has been obtained, which provides a good practicability for experiments. This photolithography technique proposed here can realize large-area, high-resolution, high-contrast, nondestructive, arbitrary-structure fabrication of nanoscale devices. (c) 2007 Elsevier B.V. All rights reserved.

超大功率二维半导体激光列阵并路自适应稳模技术

半导体列阵量子效率高,输出波长范围涵盖570～1600nm,工作寿命可达数百万小时,叠层列阵可提供超高功率激光输出,在工业、医学等很多领域具有非常广阔的应用前景。但列阵在自由运行时,各发光单元发出的光是不相干的,输出质量差,采用1/4Talbot外腔镜耦合技术,列阵实现了空间锁相最高阶超模,然而唯有基超模远场分布是中心单瓣结构,输出接近衍射极限。为得到最小谱宽、最小发散角、最大功率密度输出,必须将外腔镜倾斜β=λ/2d(λ为工作波长,d为列阵周期),这使得仅有基超模光能成像于发光单元内而被允许振荡。应用此

不同腔结构下的声光调Q双包层光纤激光器特性研究

报道了半导体激光器端面抽运不同结构的声光调Q的双包层光纤激光器的脉冲输出特性.对前向、后向不同抽运方式的掺镱调Q双包层光纤激光器在输出平均功率,调Q脉冲宽度及脉冲稳定性进行了对比及讨论;其中后向抽运的光纤激光器,在10kHz重复频率调制下,获得了斜效率为60%的平均功率输出,其脉冲宽度为52ns,单脉冲能量为0·3mJ.最后利用不同抽运方式下的速率方程,理论分析调Q脉冲的特性,分析结果与实验相符.

改善高功率激光二极管阵列光束质量的一种新方法

根据波导模理论,推导了高功率激光二极管阵列的远场分布,根据其分布特点,设计了一种离轴外腔.运用这种外腔,在工作电流为17A时,光束的束宽积从自由运转时的1100mm.mrad减小到128mm.mrad,二极管阵列的光束质量提高了8.5倍左右,输出功率约为自由运转时的75%.

激光二极管侧面抽运调Q倍频Nd:YAG激光器

对高平均功率输出的激光二极管侧面抽运电光调Q倍频 Nd:YAG激光器进行了研究，当采用90个60W的脉冲激光二极管阵列抽运时，在重复频率为10Hz下，实现了最大平均功率为1180mW的1064nm红外激光输出，光-光转换效率为11%。腔外倍频获得600mW的532nm绿光输出，倍频效率达到50%以上。

国产掺镱双包层光纤的激光特性

采用MCVD方法研发了掺镱双包层光纤，并对其结构特性、荧光特性和激光特性进行了测试和研究。其D形内包层尺寸为400／450μm，数值孔径为0．36，纤芯直径约为16μm，数值孔径约为0．18。荧光谱线的范围为1000-1140nm，1030nm处的峰宽大于50nm。采用大功率激光二极管单端泵浦6m长的双包层光纤，在泵浦人纤功率为61W时，获得了32W的激光输出，斜率效率为64％。该光纤在高功率处未发现饱和现象，通过优化光纤参数与泵浦方式还可以提高转化效率和输出功率。实验表明该光纤可以取代进口光纤用作高功率

侧面泵浦的短矩形掺钕磷酸盐玻璃光纤激光器

利用光纤－波导耦合器技术侧面泵浦一根4厘米长的短光纤，我们研制得到了一个红外波长的光纤激光器。该激光器的增益介质是横截面为矩形的掺钕磷酸盐玻璃光纤，其纤芯横截面尺寸为1.5×0.5 毫米，数值孔径为0.2。单横模激光可以通过该矩形光纤的增益-导引效应来获得。最大的激光输出功率为1.05瓦，斜率效率为10％。

氟磷酸盐玻璃的应用研究进展

氟磷酸盐玻璃系统南于其特殊的光学性能和优良的机做与热学性能一直是特种光学玻璃材料领域的一个研究热点。总结了氟磷酸盐玻璃的分类及玻璃组分与其结构的关系，综述了氟磷玻璃在光学器件、高能高功率激光玻璃、光纤激光器、光纤放大器及上转换发光基质材料等领域上的应用，并对其未来的发展进行了展望。

飞秒激光辐照ZnO晶体

利用飞秒激光对ZnO晶体进行辐照，对辐照前后的晶体样品进行发光光谱及拉曼光谱检测。辐照后发光光谱的某些发光峰强度有明显增强，但未产生新的发光峰，表明没有新的缺陷结构产生，但晶体内锌空位、间隙位锌、间隙位缺陷浓度增加。拉曼光谱结果表明，辐照后ZnO晶体未产生相变，但随着辐照激光功率的增大，拉曼峰327 cm-1，437 cm-1强度明显减弱，表明在飞秒激光辐照作用下氧化锌的结晶程度下降。但574 cm-1峰值却随着辐照功率的增大而变大，分析表明该拉曼峰很可能是由于晶体内间隙位缺陷所致。同时实验过程中观察到飞

激光尘埃粒子计数器微型光学传感器的研究

研制成功便携式激光尘埃粒子计数器的核心部件——微型光学传感器。该传感器采用直角散射光收集形式。以高功率半导体激光器作为光源，同时采用高性能的PIN型光电二极管作为光电探测器。散射光收集系统为单一大数值孔径的球面反射镜，其对粒子散射光的收集角范围从20°到160°。粒子散射光信号是脉冲信号，其频谱成份主要在高频段，所以在PIN型光电二极管后用一个带通式前置放大器来消除外界的低频噪声．根据米氏散射理论计算了该光学传感器的光散射响应特性，并用聚苯乙烯标准粒子实测了该光学传感器的性能。结果表明，该系统具有高的信噪

Encircled energy measurement for focusing lens based on scanning Hartmann test

The encircled energy of a focusing lens is one of the parameters directly affecting the target efficiency in high-power laser facilities. The direct measurement method of the encircled energy for the focusing lens based on the scanning Hartmann test is proposed in this paper. With the scanning Hartmann test setup, the information in the whole aperture of the focusing lens can be achieved. The encircled energy can be obtained by analyzing the spot diagram on the focal plane of the focusing lens. In experiments, the encircled energy of an aspheric focusing lens is measured using this method. The measurement result is in good agreement with that derived from measurement data by an interferometer and the difference is 7.7%. (C) 2006 Elsevier GmbH. All rights reserved.

gamma-LiAlO2 single crystal grown by Czochralski technique and modified by vapor transport equilibration (VTE) technique

Large-sized (similar to 2 inch, 50.8 mm) gamma-UA102 single crystal has been grown by conventional Czochralski (Cz) method, but the crystal ha's a milky, dendriform center. The samples taken from transparent and milky parts were ground and examined by X-ray diffraction. All diffraction peaks could be indexed in gamma-LiAlO2. The crystal quality was characterized by X-ray rocking curve. The full-width at half-maximum (FWHM) values are 116.9 and 132.0 arcsec for transparent and milky parts, respectively. The vapor transport equilibrium (VTE) technique was introduced to modify the crystal quality. After 1000 degrees C/48 h, 1100 degrees C/48 h, 1200 degrees C/48 h VTE processes, the FWHM values dropped to 44.2 and 55.2 arcsec for transparent and milky part, respectively. The optical transmission of transparent part was greatly enhanced from 85% to 90%, and transmission of milky part from 75% to 80% in the range of 190 similar to 1900 nm at room temperature. When the VTE temperature was raised to 1300 degrees C, the sample cracked and FWHM values of transparent and milky parts were increased to 55.2 and 80.9 arcsec, respectively. By combining Cz technique with VTE technique, large-sized and high quality gamma-LiAlO2 crystal can be obtained.

Yb：Ca5（PO4）3F激光晶体的生长缺陷

采用提拉法生长了质量优异的Yb：Ca5（PO4）2F（Yb：FAP）晶体。运用化学腐蚀，光学显微镜、扫描电子显微镜以及能量散射光谱仪观察了该晶体中的生长条纹和包裹物等宏观缺陷，以及晶体的位错腐蚀形貌、位错密度及其分布情况，同时观察了晶体中亚晶界的形态。由晶体中位错的径向变化以及生长条纹可知：晶体在生长过程中为微凸界面生长。高温下CaF2的挥发造成了在晶体生长后期熔体中组分偏离化学计量比，出现组分过冷，形成包裹物。且位错密度显著增加。Yb：FAP晶体的各向异性使得晶体在（10 10）面的位错蚀坑形状、大小以

Investigation of the spectroscopic properties of Yb3+-doped yttrium lanthanum oxide transparent ceramic

Spectroscopic properties of (Y0.9-xLa0.1Ybx)(2)O-3 transparent ceramic were studied. Two main absorption peaks of the specimen are centered at 940 and 970 nm, which are suitable for InGaAs laser diode pumping. The main emission peaks were located at 1032 and 1075 nm with larger emission cross-section and longer fluorescence lifetime than those of Yb:Y2O3. These properties of (Y0.9-xLa0.1Ybx)(2)O-3 transparent ceramic are favorable to achieve high efficiency and high power laser output. (c) 2007 Elsevier B.V. All rights reserved.