On‐Demand Dynamic Polarization Meta‐transformer

Abstract

Polarization is one of the key characteristics of light; hence its versatile manipulation plays a pivotal role in wave‐matter interaction, communication, detection, etc. Although metasurfaces have emerged as a promising platform for polarization optics, most of them only support limited polarization controls even in reconfigurable fashion. Here, an on‐demand dynamic polarization meta‐transformer operating for full Poincaré sphere by means of an ultrathin transmissive time‐varying metasurface is proposed. By temporally and independently modulating co‐polarized transmission coefficients of the metasurface for a pair of orthogonal linearly polarized incidence, the effective transmission metasurface anisotropy can be modified to mimic the desired arbitrary birefringence, thus enacting the polarization transformation between incidence and transmission waves with arbitrary polarization states. Experiments have been conducted in the microwave region to verify the design theory. This study may provide a new architecture in polarization optics and may advance the applications in vectorial polarimetry imaging, polarimetry radars, and optical/wireless communications.

Reconfigurable Metasurface: A Systematic Categorization and Recent Advances

“…2) Frequency-ampitude reconfigurable element The frequency-amplitude reconfiguration type has also been reported recently [104]. As shown in Figure 6(l), this approach involves the integration of an amplifier and a FET onto a passive structure.…”

“…(k) Illustration of frequency or frequency-phase reconfiguration[103]. (l) Frequency-amplitude R-MTS, where the amplification level is tunable at harmonic frequencies based on spacetime modulation[104]. (m) Frequency-polarization reconfiguration based on a time modulation strategy [105]…”

Generation of time-varying orbital angular momentum beams with space-time-coding digital metasurface

“…In fact, such an approach can be feasible and generalized through a space-time-coding digital metasurface with field-programmable-gate-array (FPGA) technology, particularly in the microwave regime 29 – 37 In such a case, different metasurface responses can be digitized by controlling the bias voltages with the adoption of FPGA, which offers the metasurface powerful programmability for space-time modulation.…”

Transmissive Polarization Converter with Eliminated Filtering Effect Based on Non‐Reciprocal Metasurface

“…Recently, the modulations of linear polarization, [11,12] circular polarization [13,14] and elliptical polarization [15,16] have been gradually implemented by means of the polarization conversion metasurfaces (PCMs), moreover, the designs which can generate arbitrary polarization states have emerged. [17,18] In the various functionalities of PCMs, the cross-polarization conversion is an essential one to generate any polarization state. However, when the PCMs perform the cross-polarization conversion from 𝜶 to 𝜶* (where 𝜶 represents an arbitrary polarization state), the copolarization transmission of the polarization 𝜶* is invariably suppressed.…”

“…Recently, the modulations of linear polarization, [ 11,12 ] circular polarization [ 13,14 ] and elliptical polarization [ 15,16 ] have been gradually implemented by means of the polarization conversion metasurfaces (PCMs), moreover, the designs which can generate arbitrary polarization states have emerged. [ 17,18 ]…”