摘要
介绍了非近轴光束的表示理论,利用该表示理论很好地解决了非近轴光束的角动量问题,发现非近轴光束的总角动量可以严格地分解成自旋和轨道两部分,但是两者都依赖于由偏振椭圆度表征的光束的偏振状态。主要研究了柱矢量光束的角动量问题。给出了动量空间和位形空间中的柱矢量光束表达式和角动量算符表达式。通过分析两个空间中的角动量算符及柱矢量光束表达式,发现在这两种空间中,具有螺旋型相位的柱矢量光束是角动量算符沿着传播方向的分量的本征态,其本征值与偏振椭圆度无关,这为计算这类特殊光束的角动量提供了一种新方法。
The representation theory of nonparaxial light beams is introduced.On the basis of this theory,the decomposition of angular momentum of nonparaxial light beams is well solved.The total angular momentum of an arbitrary free electromagnetic field is separated rigorously into spin and orbital parts,both of which are dependent on the state of polarization and polarization ellipticity.The angular momentum problem of cylindrical vector beams is mainly researched.Based on the expressions of cylindrical vector beams and angular momentum operators given both in momentum space and position space,it is shown that cylindrical vector beams with a helical phase structure are the eigenstates of total angular momentum in the propagation direction,and the eigenvalue of total angular momentum has no relationship with polarization ellipticity.This provides a new calculation of the angular momentum for this special kind of light beams.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2012年第6期215-218,共4页
Acta Optica Sinica
基金
国家自然科学基金(60877055
60806041)
上海市科委基金(08JC1409701
08QA14030)
上海市教育发展基金(2007CG52)
上海市重点学科(S30105)资助课题
关键词
物理光学
本征态
角动量算符
柱矢量光束
physical optics
eigenstates
angular momentum operator
cylindrical vector beams
