星载激光测高仪多模式回波是由多个目标产生的子脉冲组合而成。根据多模式目标的空间分布特点, 采用倾斜角、区域面积、中心位置和高度等参数实现其子目标的几何化建模, 结合目标响应函数的基本定义, 利用线积分的方式构建了子目标响应函数的表达形式。同时, 基于一阶矩理论推导出子目标激光测距真值及其修正值的数学模型。以星载激光测高仪GLAS系统参数为输入, 利用数值分析的方法, 模拟出子目标倾斜角、面积和位置对接收脉冲回波形态和激光测距修正值的影响。结果表明, 随着子目标倾斜角、区域面积和子目标偏离光斑中心距离的增加, 激光测距修正值也逐渐增大。针对平坦目标、缓坡目标和陡坡目标, 其激光测距修正值分别达到1.33 m、4.98 m和12.07 m, 其影响程度非常大。基于激光测距修正值的分布规律, 以子目标倾斜角、面积和中心偏距为变量, 采用线性函数描述了激光测距修正值的理论表达形式, 所得结论对于提升多模式激光测距值的测量精度具有重要的指导作用。

利用Bathe过势垒模型, 对飞秒强激光场中异核分子团簇((CH4)n, (CD4)n, (D2O)n)的爆炸动力学过程进行了理论研究。结果表明:异核团簇爆炸后产生的离子能量与团簇初始半径的平方呈线性关系, 爆炸机理为典型的库仑爆炸。研究发现, 异核分子团簇发生库仑爆炸后的氘离子能量高于飞秒强激光和单核的(D)n团簇相互作用后产生的氘离子能量, 显示异核团簇中高Z元素电离后产生的高价离子对低Z元素离子有很强的加速作用。

利用Bathe模型，理论模拟了氩团簇在飞秒强激光中(100fs，10¹⁶W／cm²)的电离和爆炸过程．研究结果显示，在团簇尺寸较小时，离子平均能量与团簇初始半径平方成正比，爆炸机制为典型的库仑爆炸．随着团簇尺寸的增加，能量增加的速度趋缓并在一定团簇尺寸后趋于饱和．模拟结果与实验数据有较好的吻合．

Using Bethe model, the dynamics of the ionization and Coulomb explosion of hydrogen clusters (0.5-5 nm) in high-intensity (10^(15)-10^(17) W/cm2) femtosecond laser pulses have been studied theoretically, and the dependence of energy of protons emitted from exploding clusters on cluster size and laser intensity has been investigated. It is found that the maximum proton energy increases exponentially with the cluster size, and the exponent is mainly determined by the laser intensity. For a given cluster size, the maximum proton energy increases with increasing laser intensity and gets saturation gradually. The calculation results are in agreement with the recent experimental observation.

An investigation of the cluster size dependence of the maximum energy of protons ejected from explosion of methane clusters in an intense femtosecond laser field has been conducted on the basis of the cluster size estimation by Rayleigh scattering measurements. The interaction of a 2*10^(16)-W/cm2 intense laser pulse (790 nm, 60 fs) with the methane clusters revealed that the clusters were Coulomb exploded and the maximum energy (E_(max)) of the protons produced was linearly proportional to the square of the cluster radius (r_(c)^(2)). In a cluster size range, with the methane cluster radii up to about 3 nm, the established relation of E_(max) and r_(c)^(2) was found to be E_(max) (keV) = 3.3+0.75r_(c)^(2) (nm2), in good agreement with the simulation results. This demonstrated that Coulomb explosion of ionic clusters (C^(+4)H^(+)_(4))_(n) took place following the cluster vertical ionization in the laser-cluster interaction.

The interaction of intense femtosecond laser pulses with rare gas clusters was studied experimentally, the time-of-flight spectra of ions from exploding clusters at different gas densities have been measured. It is found that while the relative components of ions in low and high energy of the ion energy spectrum decrease with the increase of the gas density, the average ion energies are the same for different gas densities, which indicates that the effect of gas density on laser-cluster interaction is not important under our experimental conditions.

提出一种使小型波导CO2激光器产生线偏振光输出的波导管结构,在激活介质长度250mm、总腔长310mm的条件下,获得功率大于5W、偏振度大于95％的线偏振TEM00模激光输出。