为便于评价两种光场空间分布之间的偏离程度，引入一个数学参数δ进行研究。将该参数应用到谐振腔内分析了抽运光空间分布对基模振荡光光束质量的影响。这种影响主要表现为：若抽运光在激光介质中引起非均匀的增益分布，基模振荡光将偏离高斯分布。利用δ参数对这种影响的程度进行了定量估算。定量研究表明：δ参数可以直观地反映泵浦光分布对激光器光束质量的影响程度，而且在激光器的设计中δ参数的大小可衡量泵浦光分布的优劣。对于端面泵浦二极管泵浦固体激光器（DPL），稳恒运转下最理想的抽运光分布形式是高斯型抽运光，其半径等于谐振腔的基模高斯振荡光半径。

A mathematical parameter δ is adopted to assess the different space distribution in two laser fields. The effect of the pumping light space distribution on the quality of the ground-mode oscillating beam is analyzed by applying δ in the resonant cavity. The analysis for the effect shows that the ground-mode oscillating beam will drift off the Gauss distribution if the nonequilibrium gain distribution is caused by pumping light in the laser medium. With the parameterδ, the quantitative estimation was carried out for the effect of the pump light on the quality of oscillating beam. The investigation shows that the parameterδ, can directly represent the effect of pumping light distribution on the beam quality of laser, and the value of the parameterδ can be used to judge the pumping light distribution quality. As for the endpumping DPL with continuous operation, the most ideal distribution mode of the pumping light is the Gauss pumping light and its diameter is equal to that of the fundamentalmode Gauss oscillating beam of the resonant cavity.