Broadband chirality-coded meta-aperture for photon-spin resolving

• Main Authors: Du, Luping, Kou, Shan Shan, Balaur, Eugeniu, Cadusch, Jasper J., Roberts, Ann, Abbey, Brian, Yuan, Xiao-Cong, Tang, Dingyuan, Lin, Jiao
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2018
• Subjects: Nanophotonics and Plasmonics; Nanoscience and Technology; DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/89069; http://hdl.handle.net/10220/46110
• Institution: Nanyang Technological University

The behaviour of light transmitted through an individual subwavelength aperture becomes counterintuitive in the presence of surrounding ‘decoration’, a phenomenon known as the extraordinary optical transmission. Despite being polarization-sensitive, such an individual nano-aperture, however, often cannot differentiate between the two distinct spin-states of photons because of the loss of photon information on light-aperture interaction. This creates a ‘blind-spot’ for the aperture with respect to the helicity of chiral light. Here we report the development of a subwavelength aperture embedded with metasurfaces dubbed a ‘meta-aperture’, which breaks this spin degeneracy. By exploiting the phase-shaping capabilities of metasurfaces, we are able to create specific meta-apertures in which the pair of circularly polarized light spin-states produces opposite transmission spectra over a broad spectral range. The concept incorporating metasurfaces with nano-apertures provides a venue for exploring new physics on spin-aperture interaction and potentially has a broad range of applications in spin-optoelectronics and chiral sensing.