从Wigner分布函数定义和菲涅耳衍射积分出发,导出了洛伦兹光束在束腰参考面、自由空间任一参考面以及ABCD系统出射参考面的Wigner分布函数的解析表达式。作为其典型应用,导出了洛伦兹光束二阶矩的解析表达式。数值模拟了束宽、发散角的变化规律并与相应的高斯光束参数的变化规律进行比较。结果表明洛伦兹光束比高斯型光束更适合作为二极管激光光束模型。 Based on the definitions of Wigner distribution functions and Fresnel diffraction integrals, the analytical expressions of the Wigner distribution function of Lorentz beams in the reference surface of the beam waist, the reference surface of free space and the reference surface of exit of the ABCD system are deduced. As a typical application, the analytical expressions of the second moment of the Lorentzian beam are derived. The law of beam width and divergence angle is numerically simulated and compared with the corresponding Gaussian beam parameters. The results show that the Lorentzian beam is more suitable than the Gaussian beam as the diode laser beam model.