Ultra Fast Switching of DFLC Based Dynamic Metasurfaces

Sakhare, Pratiksha A.; Dontabhaktuni, Jayasri

doi:10.3389/fphy.2022.849470

Cited by 4 publications

(4 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the current simulations we assumed very weak random surface anchoring and the topological changes in the director configuration due to geometry are ignored. Our earlier investigation on effect of geometry-induced variation in the average layer-wise director angle is of the order of near the metasurface, see 40 . Plane wave of light in the frequency range THz is incident on the bottom substrate along Z-axis (normal to the plane of metasurface) with polarization direction along Y-axis and H-field along X-axis.…”

Section: Design and Simulationmentioning

confidence: 99%

“…Dielectric metasurfaces embedded in liquid crystals are emerging as a major technology area with applications such as dynamic beam switching 34 , spatial light modulators 35 , metalens 36 , chiral metasurfaces 37 , electrically tunable switches 33 , color filters 38 , tunable second harmonic generation 26 , varifocal lens 39 , ultrafast switching 40 , etc. Most of the literature in liquid crystal based metasurfaces, however, focuses on the tunability of resonance frequencies as a function of LC orientations and switching between the resonant modes as a function of external fields.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tailoring the resonant modes in liquid crystal based all-dielectric metasurfaces

Sakhare

Atmakuri

Dontabhaktuni

2023

Sci Rep

View full text Add to dashboard Cite

High refractive index dielectic metasurfaces are being increasingly studied for their novel light-matter interactions such as Huygen’s lens, absolute transmission and complete absorption. Liquid crystal is a versatile medium with high dielectric anisotropy and hence interaction of light with the dielectric metasurfaces immersed in liquid crystal medium show complex behaviour compared to isotropic media. Most of the investigations on liquid crystal based electromagnetic response of dielectric metasurfaces focus on tunability of resonant frequencies and switching between the resonant states as a function of external stimuli such as electric field, temperature, etc. In the current work we present a detailed numerical investigation based on studies of scattering response, near-field and far-field radiation profiles of cubic Tellurium metasurfaces as a function of liquid crystal orientations in infrared frequencies. We show that the near-field and far-field radiation profiles of primary resonant modes—electric dipoles and magnetic dipoles reorient as a function of liquid crystal orientations. In particular, we study the effect of liquid crystal orientations on novel non-radiative states called anapoles. It is observed that liquid crystal orientations effect the excitation and orientation of anapole states within the Tellurium structures. This paves way for design of an electrically-driven switch between non-radiative and radiative states. Further, controlling the near-field and far-field radiation profiles opens up possibilities in designing liquid crystal based tunable multi-functional metasurfaces which can change the directionality of incident light.

show abstract

Section: Design and Simulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Tailoring the resonant modes in liquid crystal based all-dielectric metasurfaces

Sakhare

Atmakuri

Dontabhaktuni

2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Biasing the LC in a positive dielectric anisotropy frequency makes molecules rotate parallelly to the electric field, while doing so in a negative dielectric anisotropy frequency will rotate the molecules perpendicularly to the electric field. Therefore, the rising (excitation) and decaying (relaxation) transitions of molecules can be controlled independently and through an active force induced by the applied electric field, which can greatly reduce the response times [22]. The operating principle of DFLC is completely different to the previous strategies, and it does not intrinsically entail a tunability reduction.…”

Section: Introductionmentioning

confidence: 99%

Characterization and Application of Dual-Frequency Liquid-Crystal Mixtures in mm-Wave Reflectarray Cells to Improve Their Temporal Response

Guirado¹,

Rosa

Pérez-Palomino³

et al. 2023

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

Liquid Crystal-based mm-wave spatially fed antennas with electronic reconfiguration are a promising solution at the higher frequencies required in next generation networks. However, one of the main drawbacks of the technology in these bands stems from the high reconfigurability times they present. Through this work, a relevant step towards overcoming the temporal problem by using Dual Frequency Liquid Crystals (DFLC) is presented. This paper details, for the first time, both the electromagnetic and temporal characterization of four commercially available DFLC mixtures in W-band, enabling their use in designing faster devices. To evaluate the experimental characterization, a reflectarray surface (made of 50x50 cells) specifically designed to achieve fast switching times with a sufficient phase range has been manufactured and measured. For this cell, a preliminary addressing technique based on overdriving has been used, exhibiting reconfigurability (rise and decay) times of 20 ms, one order of magnitude faster than the current state of the art of LC-based mm-wave planar devices. The measured results match the simulations, and reveal that a precisely designed biasing technique using overdrive must be used for DFLCcells to achieve time reduction. Additionally, the benefits of this technology compared with other LC acceleration strategies in mm-wave are discussed.

show abstract

“…Dielectric metasurfaces embedded in liquid crystals are emerging as a major technology area with applications such as dynamic beam switching 29 , spatial light modulators 30 , metalens 31 , chiral metasurfaces 32 , electrically tunable switches 28 , color filters 33 , tunable second harmonic generation 34 , varifocal lens 35 , ultrafast switching 36 , etc. Most of the literature in liquid crystal based metasurfaces, however, focuses on the tunability of resonance frequencies as a function of LC orientations and switching between the resonant modes as a function of external fields.…”

Section: Introductionmentioning

confidence: 99%

Tailoring the resonant modes in liquid crystal based all-dielectric metasurfaces

Sakhare

Atmakuri

Dontabhaktuni

2023

Preprint

View full text Add to dashboard Cite

High refractive index dielectic metasurfaces are being increasingly studied for their novel light-matter interactions such as Huygen's lens, absolute transmission and complete absorption. Liquid crystal is a versatile medium with high dielectric anisotropy and hence interaction of light with the dielectric metasurfaces immersed in liquid crystal medium show complex behaviour compared to isotropic media. Most of the investigations on liquid crystal based electromagnetic response of dielectric metasurfaces focus on tunability of resonant frequencies and switching between the resonant states as a function of external stimuli such as electric field, temperature, etc. In the current work we present a detailed investigation of scattering response, near-field and far-field radiation profiles of cubic Tellurium metasurfaces as a function of liquid crystal orientations in infrared frequencies.We show that the near-field and far-field radiation profiles of primary resonant modes - electric dipoles and magnetic dipoles reorient as a function of liquid crystal orientations. In particular, we study the effect of liquid crystal orientations on novel non-radiative states called anapoles. It is observed that liquid crystal orientations effect the excitation and orientation of anapole states within the Tellurium structures. This paves way for design of an electrically-driven switch between non-radiative and radiative states. Further, controlling the near-field and far-field radiation profiles opens up possibilities in designing liquid crystal based tunable multi-functional metasurfaces which can change the directionality of incident light.

show abstract

Ultra Fast Switching of DFLC Based Dynamic Metasurfaces

Cited by 4 publications

References 39 publications

Tailoring the resonant modes in liquid crystal based all-dielectric metasurfaces

Tailoring the resonant modes in liquid crystal based all-dielectric metasurfaces

Characterization and Application of Dual-Frequency Liquid-Crystal Mixtures in mm-Wave Reflectarray Cells to Improve Their Temporal Response

Tailoring the resonant modes in liquid crystal based all-dielectric metasurfaces

Contact Info

Product

Resources

About