基于较简单的物理模型和矩阵光学方法, 推导了激光发射光学系统发射平面波、球面波和高斯光束的调焦公式, 并计算分析三种波的聚焦特性: 平面波调焦时, 随着调焦量绝对值减小, 聚焦距离增大, 当调焦量靠近零时, 聚焦距离增加的速度较快; 球面波调焦时, 存在聚焦距离为无穷大的准直发射状态, 若调焦量逾越该状态对应的值后, 则发射光束成为发散光束, 同时, 随着入射球面波的曲率中心距次镜的距离增大时, 准直发射状态对应的调焦量右移趋近于零; 高斯光束调焦时, 在相同调焦量下, 高斯光束的束腰位置与平面波焦点位置在远距离上存在明显的差距, 可以通过增加入射高斯光束的束腰宽度、增加激光发射光学系统的扩束比、选用波长更短的光束来减小这种差距。

Based on simple physical model and matrix optical method, the focusing adjustment formulas of plane wave, spherical wave and Gaussian beam from laser optical transmitting system are deduced. And the focusing adjustment properties of the three kinds of waves are calculated and analyzed. During plane wave focusing adjustment, with the decreasing of focusing adjustment quantity absolute value, focusing distance increases. When focusing adjustment quantity closes to zero, the increasing speed of focusing distance is faster. During spherical wave focusing, collimation emission status with infinity focusing distance exists. The emission wave beam becomes divergent if focusing adjustment quantity is over the values corresponding to the state. At the same time, with the increasing of the distance between spherical wave curvature center and secondary mirror, the focusing adjustment quantity corresponding to collimating emission state move right and close to zero. During Gaussian beam focusing and with same focusing adjustment quantity, there is an obvious difference between Gaussian beam waist and plane wave focus position in far distance. The difference can be reduced through increasing the waist width of incoming Gaussian beam and the expanded beam ratio of laser optical transmitting system and choosing shorter wavelength optical beam.