High efficiency all-dielectric pixelated metasurface for near-infrared full-Stokes polarization detection

Abstract

Pixelated metasurfaces integrating both the functions of linear polarization and circular polarization filters on a single platform can achieve full-Stokes polarization detection. At present, the pixelated full-Stokes metasurfaces mainly face the following problems: low transmission, low circular dichroism (CD) of circular polarization filters, and high requirements in fabrication and integration. Herein, we propose high performance ultracompact all-dielectric pixelated full-Stokes metasurfaces in the near-infrared band based on silicon-on-insulator, which is compatible with the available semiconductor industry technologies. Circular polarization filters with high CD are achieved by using simple two-dimensional chiral structures, which can be easily integrated with the linear polarization filters on a single chip. In addition, the dielectric materials have higher transmission than metal materials with intrinsic absorption. We experimentally demonstrated the circular polarization filter with maximum CD up to 70% at a wavelength of 1.6 μm and average transmission efficiency above 80% from 1.48 μm to 1.6 μm. Therefore, our design is highly desirable for many applications, such as target detection, clinical diagnosis, and polarimetric imaging and sensing.

Broadband Single‐Chip Full Stokes Polarization‐Spectral Imaging Based on All‐Dielectric Spatial Multiplexing Metalens

“…It is seen in Figure 6d that diffractive efficiency reaches 81.8% at the design wavelength, and average diffractive efficiencies of LP and CP light are 56.2% and 67.5%, respectively, which overcome the 50% limit of the Stokes polarization detection method with polarizers. [31][32][33][34][35][36] The experimental dispersion curve (i.e., focal length shifting with the wavelength) in the case of 0°-LP incident light is shown in + z im,0 2 ) 1/2 due to the off-axis design. It should be noted that the dispersion capability increases with the off-axis angle 𝛼, which suggests the application of multispectral image by using the proposed FSPS-SMM.…”

“…[ 35 ] Different from the multilayer design and complicated overlay process in each pixel, a single layer pixelated metasurface that utilizes Z‐shaped chiral nanostructures with circular polarization dichroism and anisotropic nanograting was proposed and demonstrated in near‐infrared for full Stokes polarization imaging, in which different circular polarization information is achieved from the natural chirality of the 2D Z‐shaped nanostructures. [ 36 ] However, in all those abovementioned pixelated DoFP methods, the optical resolution is compromised significantly by the number of CCD pixels in which the total pixels are allocated into different polarization states or spectral components, and a trade‐off exists among resolutions of optical, spectral and polarization. The energy efficiency in those systems is also limited to 50% due to the inherit characteristics of the polarizers employed in which transmission of an unpolarized incidence to a specific polarization component is 50%, either linear polarized (LP) or circular polarized (CP) component.…”

Crosstalk-free achromatic full Stokes imaging polarimetry metasurface enabled by polarization-dependent phase optimization

“…Dielectric metasurface with negligible loss provides an attractive platform for highefficiency devices, which can realize highly efficient polarization-dependent wavefront manipulation 23 and polarization multiplexing 24,25 . In addition, various dielectric polarimeters are proposed to achieve efficient polarization detection, e.g., ultracompact polarimeters 26,27 , Stokes polarization detection 28,29 , real-time polarization imaging 30,31 , snapshot imaging polarimetry 32,33 , Hartmann-Shack wavefront sensor 34,35 , and wide-angle polarimetry 36 . The performance of the polarimeter have been significantly improved, accelerating the development of polarization manipulation technology.…”

Pixelated metasurfaces for linear-polarization conversion and absorption

“…In an emerging approach for meta-atom design, the meta-atom is itself conceived as a finite biperiodic array of discrete pixels. The pixels may have simple [17][18][19][20][21][22][23][24][25][26] or complex shapes [27][28][29][30][31]. The pixels in a meta-atom can even be patched with different materials for multifunctionality and multicontrollability [17,[21][22][23]28].…”

“…Without constraining the meta-atom geometry to be symmetric, the pixelated-meta-atom approach provides the designer the ability to systematically optimize the meta-atom design with each pixel contributing significantly towards the overall performance of the metasurface. This approach was been employed for absorption [21,23], bandstop filtering [22], beam deflection [27], holography [28], radar-cross-section reduction [29,30], polarization-state detection [31], and molecular detection [20]. Let us note that simple square pixels are sufficient to represent complex shapes, as exemplified by the outputs of dot-matrix printers.…”