介绍了激光激发超声波的原理，分别给出了热弹机制和烧蚀机制下的纵波和剪切波理论波形；基于排列因子作用，提出了一种新型激光激发超声波的方法——激光定相位排列激发超声波，激光源经过定相位排列后，在某一方向上产生的超声波幅度比传统单一源产生的超声波幅度要强很多，采用此种方法，可实现对超声信号方向和强度的有效激发控制，对下一步的超声无损检测有非常重要的意义；结合实际给出了该方法的实现方式．

One of the major tasks for the ultrasound generated by laser is the discussion of the two regimes: thermoelastic regime and ablation regime,and each of the theoretical directivity patterns are mentioned. Based on the effect of array factor,a newly method of the laser ultrasonic generated by a phased array of laser beams was proposed. This means,a method to make the ultrasound field be steered and amplified in a particular direction,can be designed and implemented to enhance the signal propagation in the region of interest. It will be more significant to apply ultrasound generated by this method in nondestructive testing of materials and products. The corresponding system has been completed in practice.