【摘要】 应用标量光场的能流密度矢量 J的定义 ,计算了高斯光束在自由空间传播时 ,其光束传输轴横截面上的光强、光斑区域的能流及总能量 ,并与传统光强定义的相关结果进行了比较。计算结果表明 ,对基模高斯光束 ,仅当 kω0 1(ω0 λ)时 ,传统光强的定义才近似成立 ,否则必须采用光强的精确定义。进一步指出了高斯光束作为波动方程傍轴近似解的条件。更多还原

【Abstract】 By applying the energy flux density vector of scalar field, the light intensity, the energy flux of the light spots and the total energy flux on the transverse plane perpendicular to the propagation axial of Gaussian beam in the free space have been calculated, and the calculation results have been compared with the corresponding results of the traditional light intensity. It is pointed out that the traditional definition of the light intensity is approximately correct only if kω 01(ω 0λ), otherwise the accurate expression of the light intensity must be adopted. Furthermore, the conditions have been given that Gaussian beam is a paraxial approximation solution of the wave equation.更多还原