Microsphere-assisted super-resolution imaging with enlarged numerical aperture by semi-immersion

Microsphere-assisted imaging is an extraordinary simple technology that can obtain optical super-resolution under white-light illumination. Here, we introduce a method to improve the resolution of a microsphere lens by increasing its numerical aperture. In our proposed structure, BaTiO3 glass (BTG)...

Full description

Saved in:
Bibliographic Details
Published in:Applied physics letters 2018-01, Vol.112 (2)
Main Authors: Wang, Fengge, Yang, Songlin, Ma, Huifeng, Shen, Ping, Wei, Nan, Wang, Meng, Xia, Yang, Deng, Yun, Ye, Yong-Hong
Format: Article
Language:English
Subjects:
Applied physics
Barium titanates
Elastomers
Image resolution
Lenses
Microscopes
Microspheres
Numerical aperture
Refractivity
Silicon dioxide
Submerging
White light
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Microsphere-assisted imaging is an extraordinary simple technology that can obtain optical super-resolution under white-light illumination. Here, we introduce a method to improve the resolution of a microsphere lens by increasing its numerical aperture. In our proposed structure, BaTiO3 glass (BTG) microsphere lenses are semi-immersed in a S1805 layer with a refractive index of 1.65, and then, the semi-immersed microspheres are fully embedded in an elastomer with an index of 1.4. We experimentally demonstrate that this structure, in combination with a conventional optical microscope, can clearly resolve a two-dimensional 200-nm-diameter hexagonally close-packed (hcp) silica microsphere array. On the contrary, the widely used structure where BTG microsphere lenses are fully immersed in a liquid or elastomer cannot even resolve a 250-nm-diameter hcp silica microsphere array. The improvement in resolution through the proposed structure is due to an increase in the effective numerical aperture by semi-immersing BTG microsphere lenses in a high-refractive-index S1805 layer. Our results will inform on the design of microsphere-based high-resolution imaging systems.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.5011067