用高动态范围的相关器研究强激光脉冲的噪声分布

建立了一台动态范围大于１０＾７的三阶相关装置,利用它对习飞秒放大激光脉冲的背景强度的时间分布进行了测量。测量结果显示,在激光主脉冲的前后,分别存在有强度为主脉冲强度的１０＾－５倍的本底噪声。     

飞秒和纳秒激光脉冲作用下等离子体X射线辐射特性

对飞秒和纳秒激光作用下的Ａｌ和Ｃｕ等离子体的Ｘ射线辐射进行了测量、分析和比较．实验结果表明在飞秒激光脉冲下等离子体Ｘ射线峰值向短波方向移动．同时Ａｌ等离子体的的电离阶数和温度在飞秒下比纳秒高．     

INTERACTION BETWEEN A MOVING ATOM AND AN ELECTROMAGNETIC WAVE

Dynamics of a two-level atom moving in an electromagnetic field is studied. The atomic motion gives rise to a momentum-dependent detuning which holds back the atomic transition, and leads to a momentum-dependent Rabi oscillation which causes an overlapping among different Rabi oscillations. When the field is in a Fock state, the atomic population and the mean momentum of the atom exhibit damping oscillation, the damping rate is related to the momentum distribution; the collapse-revival phenomena of the atomic population and the mean momentum will occur if the atomic momentum has some special distribution. When the field is in a superposition state, the collapse-revival phenomena are modified by the atomic momentum distribution and disappear for the wider atomic momentum wavepackets. We also find that each atomic level will split into two sublevels with the same energy difference when the field is in a Fock state and the atom has a definite momentum.     

POPULATION TRAPPING IN MULTI-LEVEL SYSTEM VIA QUANTUM INTERFERENCE

Population trapping via quantum interference in a multi-level system driven by a coherent field is investigated. The influences of the alignment of the transition dipole moments and the energy-level separation of the upper levels are taken into account. Detailed trapping population profiles under the different conditions are given. The research result is helpful for simplifying the theoretical model and selection rational energy level system.     

DISTANCE BETWEEN DENSITY OPERATORS IN MULTIPHOTON PROCESSES

In this paper we investigate the distance between density operators in multiphoton processes. We study the distances between the time-evolved states of the atom, of the field, and of the total system and their respective reference states, compare them with the atomic inversion as well as the purity of the field, disclose their corresponding relations in various multiphoton processes. The physical interpretations are given by using a fully quantized Bloch equation in the two-photon process.     

共焦扫描系统扫描深度与厚度失真分析

采用几何光学方法对共焦系统扫描时产生的扫描深度与厚度失真进行了理论分析,对名义扫描深度与实际扫描深度之间的关系进行了研究.以若丹明6G薄膜与玻片组成的多层样品为模型,对其进行了模拟计算,得到了扫描深度与厚度失真与系统数值孔径、折射率和样品厚度之间的关系.在实验上分别采用单光子荧光和双光子荧光作为检测信号,在反射式共焦扫描系统上进行了纵向扫描实验,并与模拟计算的结果进行了比较和分析.     

Diode-pumped efficient laser action of Yb~(3+):LYSO crystal

Effective diode-pumped continuous wave (CW) tunable laser action of a new alloyed crystal Yb:LYSO is demonstrated. The alloyed LYSO crystal possesses the desirable physical and laser performance of La2SiO5 (LSO), as well as the favorable growth properties and costs of Y2SiO5 (YSO) in the same time. With a 5 at.-% Yb:LYSO sample, the output power of 2.84 W at 1085 nm and an optical-to-optical conversion efficiency of 54.5% are achieved. Its laser wavelength can be tuned over a broad range of 81 nm, from 1030 to 1111 nm.     

消像散掠入射平场光栅谱仪及其在等离子体XUV光谱诊断中的应用

研制成一台由柱面反射镜和球面反射镜组成的掠入射前置光学系统和变间距球面光栅组成的掠入射平场光栅谱仪,它不仅有较高的效率和光谱分辨,调整方便,而且还具有在4.4nm～30nm波长范围里同时获得一维空间分辨光谱的能力.用该谱仪成功地获得了线聚焦激光产生的Si,Cu及其它元素的等离子体柱的轴向空间分辨光谱.该谱仪很适合与具有平直接收表面的光电探测器,如软X射线条纹相机等联用以获得时间分辨光谱.     

PtⅢ离子5d^8—5d^76P跃迁的极紫外光谱计算

本文运用多组态Hartree-Fock加相对论修正方法(MCHFR)计算了PtⅢ离子5d~8-5d~76p跃迁的光谱,得到了有关光谱数据如波长、振子强度和辐射跃迁几率,并就计算结果进行了简要分析.     

超短脉冲强激光与等离子体的非线性相互作用

超短脉冲强光与等离子体相互作用是近年来令人注目的一个前沿领域。介绍了其中的超短脉冲强激光与非稠密等离子体作用中的激光尾波场与尾波场加速器、光脉冲频率上转换与脉宽正缩、相对论光导等重要研究课题。还介绍了超短脉冲强激光与固体靶作用听吸收机制，短标尺长等离子体产生、能量输运等有关问题的研究。