几种描述光束傍轴性定义的比较研究  

Comparative study on several definitions of beam paraxiality

作　　者：崔学才[1] 连校许[1] 吕百达[1] 

机构地区：[1]四川大学激光物理与化学研究所,成都610064

出　　处：《强激光与粒子束》2011年第12期3255-3259,共5页High Power Laser and Particle Beams

基　　金：国家自然科学基金项目(10874125)

摘　　要：以平顶高斯光束为例,对光束傍轴度3种定义,即傍轴估计量、傍轴度和傍轴度修正式做了解析研究和计算分析。结果表明,当束腰宽度与波长之比很小时,三者存在显著差异,傍轴估计量会导致非物理结果。而对实际应用中感兴趣的束腰宽度与波长之比取中间值情况,傍轴度和傍轴度修正式得出类似的结果。因此,傍轴度和傍轴度修正值都可以用来描述光束的傍轴性。Taking the flatted Gaussian beam as an example,several definitions of beam paraxiality,i.e.paraxiality estimator,degree of paraxiality,and revised degree of paraxiality,are studied analytically and illustrated numerically.It is shown that there exists a remarkable discrepancy among the three definitions when the waist width-to-wavelength ratio is small,and the paraxiality estimator will lead to a non-physical result.Whereas,the degree of paraxiality and the revised degree of paraxiality provide similar results for intermediate values of waist width-to-wavelength ratio,which are of interest in practice.Thus they both can be used for the description of beam paraxiality.

关 键 词：傍轴估计量 傍轴度 傍轴度修正值 平顶高斯光束 

分 类 号：O436.1[机械工程—光学工程]