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Design and characterization of a bilayer wire-grid polarizer as a variable-angle polarizing beam splitter
Optics Express
|May 4, 2026
Summary
This study presents a silicon-based wire-grid polarizer (WGP) acting as an angularly tolerant polarizing beam splitter (PBS). The novel device achieves high efficiency and contrast over a wide range of angles, enabling integration with silicon photonics.
Area of Science:
- Nanophotonics and optical devices
- Integrated photonics and silicon-based technologies
Background:
- Wire-grid polarizers (WGPs) are nanostructures polarizing light.
- Bilayer WGPs utilize two offset wire grids with a dielectric grating.
- Existing designs often use low-index dielectrics, limiting silicon integration.
Purpose of the Study:
- To demonstrate a silicon-and-aluminum bilayer WGP operating near 1550 nm.
- To optimize the device as an angularly tolerant polarizing beam splitter (PBS).
- To assess its compatibility with silicon-based optical systems.
Main Methods:
- Fabrication of a silicon-and-aluminum bilayer WGP.
- Experimental characterization of transmittance and reflectance over a wide angular range (-50° to +50°).
- Evaluation of contrast ratio for transmissive WGP performance.
Main Results:
- Achieved >58% transmittance and >93% reflectance over -50° to +50° incidence angles.
- Demonstrated high contrast ratios (>1000:1) as a transmissive WGP.
- Identified potential for 82% transmission efficiency with reduced Fresnel reflection.
Conclusions:
- The silicon-based bilayer WGP functions as a high-efficiency, angularly tolerant PBS.
- The device leverages silicon processing and is compatible with silicon photonics integration.
- Further improvements can enhance transmission efficiency for broader applications.
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