摘要
在光束能量传输的分析中,对能量集中度的研究具有十分重要的意义,能量集中度是评价光束质量的手段之一。采用光强的精确定义给出了经圆孔衍射的非傍轴标量光束能量集中度η的精确积分表示。对平面波圆孔衍射的能量集中度η随着衍射孔径ρ_0和传播距离z的变化进行了详细的数值计算,结果表明,η随着z的增加只是在特定条件下才单调减小,η随着ρ_0的增加不是单调变化,ρ_0取某个特定的孔径值时η取得极大值。根据该结果给出了通过控制参数ρ_0和z的取值获得光斑最大能量或最大能量集中度的方法。
Energy concentration degree which can evaluate the beam quality is significant while analyzing the energy transmission of the beam. The accurate integral expression of energy concentration degree η of nonparaxial scalar beam diffracted by circle aperture is deduced by accurate definition of light intensity. Detailed numerical calculations are carried out to discuss the law of η versus diffraction aperture ρo and transmission distance z. It＇s shown that η increases monotonously with the increase of z only under some conditions. η does not increase monotonously with the increase of ρo and it gets the extremum if ρo is taken as a special value. The approach to get the largest energy and energy concentration degree of a spot is given by controlling the parameters ρo and z.
出处
《量子电子学报》
CAS
CSCD
北大核心
2009年第2期134-137,共4页
Chinese Journal of Quantum Electronics
基金
国家自然科学基金(50776084)资助项目
关键词
物理光学
非傍轴光束
能量传输
圆孔衍射
能量集中度
physical optics
nonparaxial beam
energy transmission
circle aperture diffraction
energy concentration degree
