Temperature tunable electromagnetically induced transparency in terahertz metasurface fabricated on ferroelectric platform

Abstract

The integration of active materials in terahertz (THz) metasurfaces is pivotal for the realization of functional device applications in diverse fields like sensing, imaging, communication, etc. In this context, ferroelectric materials endowed with tunable electro-optic properties have recently emerged as a novel candidate for achieving actively tuned THz metasurfaces. Here, we experimentally investigate temperature tuning of electromagnetically induced transparency (EIT) effects in a THz metasurface based on ferroelectric barium titanate (BaTiO3) thin film. We characterize tunable dielectric properties of the BTO thin film under variable temperatures (25 0C to 100 0C) at THz frequencies by utilizing THz time domain spectroscopy (THz-TDS) technique. Based on this aspect, we intelligently design a THz metasurface capable of displaying the EIT effect. THz transmissions through the metasurface sample are then probed for different applied temperatures. The EIT features undergo frequency shifts along with amplitude modulations owing to the temperature induced variations of the dielectric properties of the BTO thin film. A total red shift ~ 27 GHz in EIT resonance dip is observed experimentally as the temperature increases from 25oC to 100oC. Therefore, we demonstrate utilities of ferroelectric platform towards the development of temperature tunable EIT metasurfaces.

Roadmap for phase change materials in photonics and beyond

“… 106 , 107 Temperature tunable EIT in THz frequencies was demonstrated by fabricating metasurface on ferroelectric platform. 108 Through thermal annealing and laser pulses, reversible and repeated switching of multiple devices including the dynamic beam splitter, bifocal meta-lens, dual mode focusing optical vortex generators, and switchable metalenses/focusing optical vortex generators have been realized. However, a critical challenge in this spectral region is the limitation in switching speed when dealing with larger areas of THz PCM devices.…”

Sensing of nanoporous 2D materials like r-GO using THz hole arrays

“…The permittivity of rGO film (see Fig. 2(b)) is extracted using Drude's model to feed the material property in the numerical simulation [26]. The pristine hole array sample used in this study along the dimensions is given in Fig.…”

Recent Advances in Tunable Metasurfaces and Their Application in Optics

“…In a recent paper [ 96 ], a metasurface based on barium titanate (BaTiO 3 ) topped by a strip coupled to two U-shaped resonators made of aluminium metal on a MgO substrate, fabricated with standard photolithography, was characterized using THz time domain spectroscopy. The transmission through the samples was measured at different temperatures in the spectral window of 0.4–0.9 THz.…”