Polarization-Multiplexed Dielectric Metasurface

Updated 18 October 2025

Polarization-multiplexed dielectric metasurfaces are planar optical devices that use anisotropic nanoresonators to manipulate polarization channels, phase, and amplitude with high precision.
They employ Jones matrix engineering and geometric phase techniques to achieve broadband, independent modulation across multiple polarization channels with high efficiency.
Experimental realizations demonstrate up to 90% total transmission and 99% polarization conversion efficiency, making them ideal for imaging, communication, and quantum optics applications.

A polarization-multiplexed dielectric metasurface is an engineered planar optical device composed of subwavelength-spaced dielectric nanoresonators, whose geometry and arrangement enable deterministic, spatially resolved manipulation of the polarization, phase, and amplitude of transmitted or reflected light. Such metasurfaces leverage anisotropic, birefringent, or asymmetric dielectric scatterers to realize local Jones matrices with tunable eigenaxes and phase retardations, allowing independent or coupled control over multiple polarization channels within a single, flat nanostructured element. This platform provides an integrated approach for multiplexing distinct functionalities—such as focusing, wavefront shaping, mode conversion, holography, or depolarization—across orthogonal, arbitrary, or even entangled polarization states within a diffraction-limited spatial footprint.

1. Fundamental Principles: Jones Matrix Engineering and Polarization Conversion

The operation of polarization-multiplexed dielectric metasurfaces is rigorously described within the Jones matrix formalism. Each local meta-atom (e.g., an elliptical or rectangular dielectric nanopost) acts as a localized birefringent element with its own principal axes and phase retardations. The general transmission matrix at each metasurface pixel can be written as

$T = R(\theta) \begin{bmatrix} e^{i\varphi_x} & 0 \ 0 & e^{i\varphi_y} \end{bmatrix} R(-\theta),$

where $\varphi_x$ and $\varphi_y$ are the phase shifts along the principal axes, and $R(\theta)$ is a rotation matrix parameterized by the orientation angle $\theta$ of the nano-post relative to a fixed basis. By tuning size (diameter $D_x$ , $D_y$ ) and orientation ( $\theta$ ) of each nano-post, any symmetric, unitary local Jones matrix can be realized (Arbabi et al., 2014). This allows a metasurface to impart arbitrary local transformations to the incident polarization, including full wave-plate functionality (quarter, half), arbitrary geometric phase profiles, or polarization-dependent holographic patterns.

A crucial extension is the ability to spatially encode two (or more) independent phase and amplitude profiles under orthogonal incident polarization states, enabling simultaneous, spatially resolved polarization multiplexing. For arbitrary orthogonal (potentially elliptic) polarization bases, the metasurface decomposition enables fully independent complex-amplitude (phase and amplitude) modulation in each channel (Bao et al., 2021).

2. High-Efficiency and Broadband Polarization Multiplexing

Polarization-multiplexed dielectric metasurfaces achieve high transmission efficiency owing to their all-dielectric composition (e.g., amorphous silicon, TiO₂, or Si₃N₄), which circumvents the Ohmic losses afflicting plasmonic analogs (Arbabi et al., 2014, Kruk et al., 2016). The spatial lattice constant is maintained at subwavelength scale (e.g., 650 nm at λ = 915 nm) to preclude higher-order diffraction and ensure high spatial resolution.

To extend operation bandwidth, the multipolar Huygens principle is adopted: meta-atoms are designed to exhibit overlapping electric and magnetic dipole, quadrupole, or higher-order Mie-type resonances, enabling broadband reflection suppression and transmission phase control (Kruk et al., 2016). Experimentally, such metasurfaces have demonstrated total transmission up to ∼90% and polarization conversion efficiency of ~99% over C and L telecommunication bands, and can impart effective birefringence $\Delta n \simeq 0.9$ (exceeding natural crystals by >3 $\times$ ) within propagation thicknesses of several hundreds of nanometers.

3. Device Architectures and Implementation Strategies

3.1 Meta-atom Design: Birefringent and Geometric Phase

Meta-atom design strategy typically falls into two types:

Intrinsic Birefringence: The phase delay between orthogonally polarized field components is engineered by varying aspect ratio and orientation. Each pixel can locally implement a specific waveplate with independently set retardance and eigenaxes (Arbabi et al., 2014, Kruk et al., 2016).
Pancharatnam–Berry (Geometric Phase): By rotating anisotropic scatterers (e.g., nanofins or nanorods) by angle $\theta$ , incident circularly polarized fields acquire geometric phases of $2\sigma\theta$ , where $\sigma$ is the incident helicity. This enables spatially encoding independent phase profiles for LCP and RCP channels (Dong et al., 2018).

3.2 Polarization-Channel Multiplexing

To achieve independent or coupled manipulation for two or more polarization channels, metasurfaces may:

Superimpose or Interleave Meta-atoms: Arrays are locally patterned so that, under different polarizations, distinct sets of meta-atoms contribute to the output. Examples include “dual-color” or “dual-image” holograms, stereo image displays, or independent full-color prints for arbitrary elliptical polarizations (Bao et al., 2021).
Composite or Dimerized Meta-molecules: Dimerization (meta-molecules with controlled separation and orientation) enables arbitrary polarization conversion dichroism, where transmission from one state (any point on the Poincaré sphere) to its handedness-flipped state is maximized while the orthogonal state is blocked; this yields a general “full-Poincaré sphere polarizer” (Wang et al., 2020).

3.3 Nonlinear Optical Multiplexing

Recent advances extend polarization multiplexing to the nonlinear regime. Here, the tensorial nonlinear susceptibility (e.g., third-order $\chi^{(3)}$ ) is engineered by meta-atom symmetry to control the amplitude and polarization of generated harmonics (such as THG), with phase and polarization of the nonlinear emission dictated by meta-atom orientation, enabling spatial separation of polarization states into different diffraction orders—an effective “nonlinear polarization metagrating” (Yue et al., 3 Sep 2025).

4. Application Domains and System Integration

Polarization-multiplexed dielectric metasurfaces enable or substantially advance the following applications:

Mode and Channel Multiplexed Communications: Single metasurfaces can convert orthogonal polarizations of fundamental fiber modes into distinct higher-order spatial modes for use in high-capacity, polarization-division-multiplexed (PDM) or space-division-multiplexed (SDM) optical links and LiFi (Kruk et al., 2017).
Imaging and Polarimetry: All-dielectric metasurface polarimeters, using asymmetric bi-meta-atom designs, extract full Stokes parameters (with fidelity $\approx 99\%$ ) for any arbitrary polarization in a single shot, enabling ultra-compact polarization imaging and quantum state tomography (Shah et al., 2022).
Full-Poincaré Sphere Polarization Generation: Monolithic metasurfaces that operate as “all-in-one” polarizers, producing arbitrarily specified polarization from unpolarized input—with measured polarization dichroism exceeding 90%—streamline optical architectures in imaging and display (Wang et al., 2020).
Polarization Scrambling and Depolarization: Spatially varying orientation distributions of anisotropic meta-atoms enable efficient depolarization (ultralow integrated DoP $_\Omega$ ), with minimized point-spread function (PSF) splitting and minimal image degradation, advancing calibration in spaceborne and hyperspectral imaging (Hartmann et al., 29 Apr 2025).
Information Encryption and Security: Two-dimensional (2D) encoding across polarization and wavelength channels (e.g., six channels in (Dong et al., 2018)) increases the number of independent combinations exponentially, enhancing data security and anti-counterfeiting.
Integrated Quantum Optics and Nonlinear Upconversion: Through precise control of nonlinear phase and polarization by geometry, metasurfaces enable all-optical, ultrafast polarization manipulation for quantum light sources, chiral sensing, and on-chip quantum processing (Luan et al., 10 Dec 2024, Yue et al., 3 Sep 2025).

5. Experimental Realizations and Performance Metrics

The state-of-the-art experimental devices demonstrate:

Transmission efficiency: 72–97% (linear regime, (Arbabi et al., 2014)), up to 90% (broadband, (Kruk et al., 2016)), with nonlinear devices determined by application-specific trade-offs.
Polarization conversion efficiency: up to 99% for broadband half- and quarter-waveplates, vector beam q-plates, and full-Poincaré polarizers.
Channel capacity and selectivity: Extinction ratios exceeding 20 dB for mode conversion in PDM/SDM systems (Kruk et al., 2017); integrated DoP $_\Omega$ down to near zero in depolarizers (Hartmann et al., 29 Apr 2025).
Functional diversity: Simultaneous, independent holographic images, tunable focal lengths, and varifocal achromatic operation under distinct polarization channels (Ou et al., 2022).
Quantum state fidelity: Polarimeter state reconstruction fidelity of 99 ± 1% and resolution of 5°, enabling quantum state tomography without moving parts (Shah et al., 2022).

6. Limitations, Challenges, and Future Perspectives

Several implementation challenges persist:

Fabrication constraints: Precise control of anisotropy, orientation, and inter-element spacing is critical; especially for multi-wavelength and broad angular support, maintaining uniformity across large areas remains nontrivial.
Dynamic reconfiguration: Most metasurfaces are static; dynamic tuning (via mechanical, electrical, or liquid crystal integration) is advancing but introduces complexity in device packaging and uniformity (Hu et al., 2020, Ou et al., 2022).
Bandwidth and crosstalk: Dispersion control for achromatic devices often requires computational phase matching (e.g., through PSO), and ensuring spectral overlap or channel isolation against crosstalk is an active area (Ou et al., 2022).
Nonlinear efficiency: Nonlinear multiplexed devices offer enhanced functionality but often with lower conversion efficiencies compared to linear counterparts and require efficient phase-matching without sacrificing polarization selectivity (Yue et al., 3 Sep 2025).
Integration and large-scale deployment: Coupling metasurfaces with detectors and external modules (e.g., fiber arrays, CMOS sensors) at scale, as demonstrated in (Soma et al., 2023), is an ongoing engineering endeavor.

7. Comparative and Historical Context

Dielectric polarization-multiplexed metasurfaces fundamentally surpass the limitations of:

Plasmonic metasurfaces, which suffer from low efficiency due to losses.
High-contrast gratings, which lack complete in-plane phase and polarization control.
Diffractive elements and SLMs, which are bulky and dynamic only within limited phase and polarization modulation domains.
3D chiral nanostructures, which lack full Poincaré sphere programmability and integration.
Bulk optical layouts, which require cascaded polarizers, waveplates, and lens assemblies; metasurfaces achieve the same or greater functional density with subwavelength thickness.

The rapid evolution of metasurface design and characterization, notably the advances in Jones matrix engineering, geometric phase multiplexing, and artificial nonlinearity, mark an ongoing shift towards programmable, multiplexed nanophotonic components, supporting both fundamental research and practical, high-density, integrated photonic systems across classical and quantum domains.