中文摘要：

高斯光束的传播特性直接影响激光雷达大气回波信号的发散角,进而影响法布里-珀罗标准具（FPE）的光学特性。从高斯光束的FPE三维干涉环分析,得到发散角小的高斯光束有利于获得能量较高的FPE零级或一级干涉环。探讨了高斯光束品质因子M2和准直倍率对不同高度的激光大气回波信号的影响。数值计算结果表明,FPE对大气回波信号的透射率与高度的变化有关,在近场变化明显,在远场相对稳定;且对特定高度大气回波信号的FPE透射率随着光束品质因子M2的增大而降低,随着准直倍率的放大而增强。所以应设计和选择具有较高准直倍率的准直发射系统和具有较低光束品质因子M2的激光光束,来提高FPE的透射率,同时对以FPE分光的激光雷达的近场回波信号进行FPE透射率校正,以改善激光雷达系统的测量误差。

英文摘要：

The beam divergence angle of lidar returned signals which is directly influenced by propagation properties of Gaussian beam affects the properties of Fabry-Perot etalon（FPE）.In this paper,the three-dimensional interference rings of Gaussian beam are investigated and manifested to some trend.Gaussian beam with small divergence may be propitious to obtain higher energy of FPE zero-order or first-order interference ring.For a lidar system,the effects of beam quality factor M2 and expander coefficient on returned signals are discussed.The numerical results indicate that FPE transmission is changed clearly with the height in the near field and leveled off in the far field,and at a given height,it decreases with the enhance of the value of M2 and increases with the expander.It is supposed that laser with lower beam quality factor M2 and the transmitter with higher expander coefficient are chosen and developed to improve FPE transmission and in the near field decrease the measurement error in lidar using an FPE as spectroscope,which is expected to supply numerical foundation for the lidar system.