针对脉冲激光器，提出了一种根据激光单脉冲能量空间分布测量激光横模结构的方法，构造了相应算法，并通过理论和实验验证了该方法.通过对调Q二极管泵浦固体激光器的调Q过程进行数值模拟，计算出单脉冲能量空间分布曲线和各阶横模比例，同时根据单脉冲能量空间分布曲线上一些离散点计算出各阶横模比例，且与调Q过程数值模拟的直接计算结果相等.同时在实验中根据测量出的单脉冲能量相对值，计算出各阶横模比例，拟合出腔外不同距离处的单脉冲能量空间分布曲线.对腔外不同距离处单脉冲能量相对值和相应拟合曲线进行比较，发现测量值和拟合曲线吻合.

A measuring method of transverse mode in a laser beam is presented, which is based on the spatial distribution of single pulse energy in a pulsed laser. An algorithm for this method is designed and proved to be reliable in theory and experiments. The spatial distribution curve of single pulse energy is derived by numerical simulation for Qswitched diode pumped solid state laser. The transverse mode proportion calculated by this method is exactly equal to those calculated directly by numerical simulation. An experiment is also conducted to measure transverse mode proportion by using this new measuring method. Spatial distribution of single pulse energy is obtained by testing single pulse energy at different positions in different planes. The transverse mode proportion in Qswitched diode pumped solid state laser is calculated by forming a system of equations with those testing data which is consonant with the spatial distribution curves of single pulse energy fitted by the calculated proportion and transverse mode distribution in those different planes.