调Q-YAG激光在水中自聚焦过程研究

用光学干涉探测方向和阴影法,借助光延迟装置,在同一台YAG调Q激光器上研究了1.06μm激光在水中引起自聚焦的过程.首次获得了多幅时间序列分辨的Mach-Zchnder干涉图和阴影图.观察并解释了自聚焦过程中一系列现象,并由实验论证了运动焦点理论模型.     

上、下能级都有泵浦的激光场运动方程

本文采用密度矩阵方法,在计及激光系统中上、下能级都有泵浦和场的损耗的情况下,导出了激光场的运动方程和稳态解。讨论了阈值条件及平均光子数。发现在此情况下输出光强与上能级泵浦率为r_a-r_b,下能级泵浦率为零时相同、但光子统计分布与“相干态”情况偏离更大。     

Successful operation of a cooperative SLR station of China and Argentina in San Juan

We introduced the observations and researches using a Satellite Laser Ranging (SLR) system with high precision, which was designed and made in China and installed in the Observatory of San Juan Uni- versity, Argentina, the capability of the system and the achievement of the cooperative procedure be- tween China and Argentina. The SLR station in San Juan, set up by China and Argentina, is quite sig- nificant for improving the distribution of SLR stations and enhancing the orbital coverage of the whole earth. Since the SLR system started to work in the Observatory of San Juan University in the beginning of 2006, the operation is rather good, and rich data with high precision have been obtained. Further plan of the cooperation for the near future is also presented.     

健康家兔晶状体激光拉曼光谱研究

激光拉曼光谱法被公认为是研究生物大分子的结构、动力学和功能的有效方法。对健康家兔晶状体的激光拉曼光谱进行研究,发现在710 cm-1到1 280 cm-1区域内,健康家兔晶状体表现为典型的蛋白质拉曼光谱区,说明健康家兔晶状体主要由α、β和γ-蛋白组成的,以β折叠结构为主。对家兔晶状体蛋白侧链中酪氨酸残基的微环境研究表明,晶状体中酪氨酸残基大部分处于"暴露"状态,而有一小部分处于"埋藏"状态。     

大气激光通信链路功率分析研究

在现代激光通信传输中,大气对光传输过程中的衰减和起伏影响,已严重影响了激光通信的发展。为提高通信距离、速率和通信质量,抑制大气对激光通信的不利影响是十分重要的。本文针对野战激光通信环境,对激光在大气中的传输模型进行通信链路功率计算,对大气对光功率的衰减和损耗进行了分析,为实际大气激光通信的应用提供一定的理论依据。     

基于遗传算法的双波段激光诱导荧光水体DOM浓度分析

在激光诱导荧光水体DOM（溶解有机物）浓度检测中,用遗传算法准确地分离出水体的拉曼信号,建立了DOM浓度的反演方程。实验证明,该方法具有准确、方便及计算量小的特点,有较好的应用价值。     

Influence of laser doping on nanocrystalline ZnO thin films gas sensors

The effect of laser doping of Al on the gas sensing behavior of nanocrystalline ZnO thin films is reported. The doping of Al was carried out by the spin-coating of Al-precursors on nanocrystalline ZnO films followed by a pulsed laser irradiation. The laser-doped films were characterized as a function of laser power density by measuring the optical, structural, electrical, morphological and gas sensing properties of ZnO films. It was found that the laser doping process resulted in an increase of electrical conductivity of ZnO films. The performance of gas sensor was investigated for different concentrations of H2 and NH3 in the air. The results indicate that the laser doping process can be utilized to improve the sensor characteristics such as sensitivity and response time by optimization of laser power density. The optimum laser power is interpreted as the critical power level required to compete the effective doping versus developing the effective grain boundaries. Also, the selectivity of laser-doped ZnO sensors for H2 was studied for a likelihood practical gas mixture composed of H2, NH3 and CH4. It is found that these films can be optimized to develop H2 and NH3 sensors in PPM level with a higher selectivity over other reducing gases.     

不同温度下脉冲激光沉积LiCoO_2薄膜的微观结构和表面形貌

使用脉冲激光沉积技术,不同的衬底温度,在单晶Si(100)衬底上沉积了锂离子电池正极材料Li-CoO2的薄膜.用XRD对样品进行晶体结构分析,用SEM观察了样品的表面形貌.结果显示,衬底温度对LiCoO2薄膜的微观结构和表面形貌都有明显影响.在500℃以上的衬底温度下生长的样品结晶质量较好;晶体的颗粒尺寸随着温度的升高而增大.     

激光扩束望远镜的光学变焦设计

本文论述了连续变焦的激光测距望远镜的光学系统设计方法,针对λ=1.064μm的YAG激光扩束发射光学系统进行了具体分析,给出了入射角为5mrad,放大倍率2~10倍连续可调的激光扩束器系统的光学系统结构参数和像质评价结果。     

发动机气缸套内表面激光造型加工技术

针对气缸套内表面加工采用普通机械珩磨工艺的缺点,提出了激光造型加工技术,该技术在经过镜面珩磨加工的缸壁上进行表面激光造型加工,在气缸套内表面上形成可控储油槽体系.实验证明,采用激光造型加工技术加工气缸套内表面,可降低排放减少润滑油的消耗,提高发动机的动力性、经济性、提高内燃机的使用寿命和可靠性.