Metasurface with periodic subwavelength resonators, placed on dielectric substrate is one of the main research interests in the terahertz (THz) photonics. Based on metal/graphene hybrid materials such structures can achieve giant tunable asymmetric transmission and circular dichroism (CD). In this paper we discuss a circular dichroism of metasurfaces consisted of resonators with n-fold rotational symmetry Cn, i.e. C2, C3, C4. The numerical simulation was performed using CST Microwave Studio. Theoretical analysis combines symmetry restrictions in effective polarizability approximation for calculation of transmission and reflection coefficients. The numerical simulation was done in the millimeter wave range. This research has both fundamental and applied relevance, and may be used in development of terahertz and microwave devices, such as waveplates, polarization sensitive absorbers, etc.
Recent decades metamaterials in terahertz frequencies become very popular in the scientific society. Metamaterials is an arrangement of artificial structural elements (unit cell) that gives properties which cannot be found in nature. The effective properties of metamaterials depend on their design. This fact provides a big variety in applications of metamaterials as filters, absorbers, polarizers, etc.
In this work we have studied the influence of the chiral metasurface resonator conductivity on polarizing properties of the metasurface. The unit cell of the metasurface consists of metallic gammadion crosses on both sides of the dielectric substrate. The petals of the upper resonators were partly made of different metals. Each combination of metals in design of the resonator leads to a difference in transmission of the metasurface. Due to chirality, transmission coefficients for left- and right-handed polarized waves are different. This phenomenon causes changes in the polarization ellipse of transmitted wave. The metasurface was numerically simulated using CST Microwave Studio by finite-elements method in frequency domain. The virtual experiment shows a difference in ellipticity and azimuth polarization rotation angle spectra of resonators with different conductivity. These results provide usage of materials with changeable conductivity, for example, graphene, in development of tunable polarization converter.
The investigated metasurface might be used in terahertz polarimetry of cancer, teeth and skin deceases. These measurements can be performed by terahertz time-domain spectroscopy.
The polarizing properties of chiral metasurface made of planar array of gammadion crosses placed on silicone
substrate were investigated in the frequency range of 0.1-0.3 THz. The ability of polatization properties control
of metasurface working as elliptic polarizer by gammadion petal width changing was shown.
Conference Committee Involvement (1)
Chinese-Russian Optics & Photonics Symposium for Young Scientists
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.