Abstract
We report on a high-efficiency cross-polarization conversion metamaterial design consisting of novel spiral split-ring resonators (SRRs). Numerical simulations on the resonant electric field and surface current distributions demonstrate that the cross-polarization response is attributed to the charge accumulation in the horizontal SRR gap. The dependencies of resonance frequency on the structural parameters of the SRR reveal that an inductive-capacitive resonance dominates the SRR. We further show that the polarization conversion efficiency can be significantly enhanced by integrating two orthogonal gratings, which enable a linear polarization wave to be rotated to its orthogonal direction with a high efficiency of ∼90%. These results offer a way to engineer novel high-performance metamaterial polarization devices.
Highlights
Since polarization is one of the most fundamental but important properties of electromagnetic (EM) waves, controlling and manipulating the polarization state of EM waves efficiently are of great importance in many areas involving imaging, sensing, and telecommunication.1–5 The realization of polarization manipulation usually relies on birefringent materials or dichroic crystals,6–8 which are required in a bulky volume to enable sufficient retardation accumulated between the two orthogonally polarized components, which limits their integration into optical systems
The results show that when excited by an incident electric field polarized in the horizontal direction, the resonant current in the split-ring resonators (SRRs) can drive the charges to accumulate in the SRR gap and form a vertical electric dipole
We further demonstrate that the polarization conversion efficiency can be significantly improved by placing two orthogonal gratings on both sides of the SRR array
Summary
Since polarization is one of the most fundamental but important properties of electromagnetic (EM) waves, controlling and manipulating the polarization state of EM waves efficiently are of great importance in many areas involving imaging, sensing, and telecommunication. The realization of polarization manipulation usually relies on birefringent materials or dichroic crystals, which are required in a bulky volume to enable sufficient retardation accumulated between the two orthogonally polarized components, which limits their integration into optical systems. Metamaterials have been widely proposed to control and manipulate the polarization states of EM waves owing to their ultrathin thickness and scaling properties, which exhibit excellent performances in polarization modulation.9–11 Among these metamaterial polarization converters, anisotropic structures such as split-ring resonators (SRRs) and cut wires have been widely used as basic building blocks for their birefringence effect, which is suitable for polarization conversion. The results show that when excited by an incident electric field polarized in the horizontal direction, the resonant current in the SRR can drive the charges to accumulate in the SRR gap and form a vertical electric dipole This induced electric dipole strongly radiates waves orthogonal to the incident electric field, producing a cross-polarization response. The incident wave can be converted to the orthogonal direction with a high efficiency of 90%
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
