Generation of a Nondiffracting Superchiral Optical Needle for Circular Dichroism Imaging of Sparse Subdiffraction
Haifeng Hu1,2, Qiaoqiang Gan1,3, Qiwen Zhan1,4
1School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
Abstract:
Chirality describes not only the structural property of three-dimensional objects, but also an intrinsic feature of electromagnetic fields. Here we report a strategy to realize a Bessel beam superchiral "needle" by focusing a twisted radially polarized beam on a planar dielectric interface. By tailoring the light spatial distribution in the pupil plane of a high numerical aperture lens, the chirality of the local field at the focus can be enhanced by 11.9-fold than that of a circular polarized beam. Through a combined interaction of chiral and achiral transitions, the dimension of the region with enhanced chiral sensitivity can be shrunk down to λ/25. This theoretical work paves the way towards a completely new label-free imaging technique using the enhanced circular dichroism for sparse subdiffraction chiral objects (e.g., individual molecules).
Related Concept Videos
Deformation in a Circular Shaft
Imaging Biological Samples with Optical Microscopy
In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage...
Uniform Circular Motion
Non-uniform Circular Motion
For example, such...
Dynamics of Circular Motion
Any acceleration must be produced by some force. Therefore, any force or combination of forces can cause centripetal acceleration. A few examples include the tension in the rope on a...
Stress Concentrations in Circular Shafts


