Analysis of near-field subwavelength focusing of hybrid amplitude-phase Fresnel zone plates under radially polarized illumination

作者：Zhang Yaoju^*; Zheng Chongwei; Zhuang Youyi; Ruan Xiukai

来源：Journal of Optics, 2014, 16(1): 015703.

DOI：10.1088/2040-8978/16/1/015703

• subwavelength Fresnel zone plate
• near-field focusing
• angular spectrum theory

The near-field focusing properties of actual hybrid amplitude-phase binary subwavelength Fresnel zone plates (HBSFZPs) are studied theoretically. The analysis based on the exact vector angular spectrum method is done for a radially polarized beam incident on the HBSFZPs. The results show that the near-field subwavelength focusing with a long depth of focus can be obtained using an HBSFZP, which is very useful for near-field subwavelength photolithography and high-resolution microscopy. The position of the actual focus in the near-field focusing HBSFZPs depends on the evanescent wave rather than the propagating wave. The etch depth has an important influence on focusing properties of HBSFZPs.

• 出版日期2014-1
• 单位温州大学