摘要
设计了一种可产生长距离近似无衍射光束的新型光学元件凹锥透镜,该透镜是以轴线为中心将传统轴棱锥的底面磨削成凹球面。采用几何光学理论分析了其产生长距离近似无衍射光束的原理。推导了凹锥透镜的振幅透射率函数,并由衍射理论分析和模拟了平面波通过其后的光强分布特性。结果表明,相对于传统轴棱锥,选择合适曲率半径的凹锥透镜能够产生光束发散小、轴向光强分布均匀的长距离近似无衍射光束。以折射率n=1.51509,底角γ=10°,曲率半径R=75mm的凹锥透镜为例,入射光束半径a=10mm时可产生最大无衍射距离为Zmax=471.220mm的近似无衍射光束,相同参数条件下的传统轴棱锥只能产生最大无衍射距离为Zmax=111.235mm的近似无衍射光束,比较可知无衍射距离增大了359.985mm。
A new type of axicon is proposed for generating quasi long-distance non-diffracting beams. This new type of optical element is grinded to a concave spherical surface on the bottom of a traditional axicon. The formation of the long-distance non-diffracting beams is analyzed by the theory of geometrical optics. Its amplitude transmissivity function is derived. The intensity distribution of plane wave pass through the concave axicon is simulated by diffraction theory. The results show that the appropriate radius of curvature of axicon can produce long-distance non- diffracting beams with low divergent and good uniformity. Take an axicon with base angle ）＂ of 10° , refraction index n of 1. 51509 and curvature radius R of 75 mm for example, the maximum non-diffracting distance Zmax of 471. 220 mm is obtained when radius of the incident beam a is 10 mm, while the traditional axicon with the same base angle and refraction index can obtain non-diffracting distance of 111. 235 mm. The non-diffracting distance increases by 359. 985 ram.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2013年第5期69-73,共5页
Acta Optica Sinica
基金
国家自然科学基金(61178015)
国家高功率激光物理重点实验室开放基金(SG001102)
福建省自然科学基金(2012J01278)
泉州市科技重点项目(2011G9)资助课题
关键词
几何光学
长距离近似无衍射光束
轴棱锥
振幅透射率
凹锥透镜
geometric optics long-distance quasi-non-diffracting beam
axicon
amplitude transparency concave axicon
