Infrared micropolarizer array fabricated using a reversal nanoimprint.

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Micropolarizer arrays are crucial optical components for polarization control.
• Existing fabrication methods can be costly and complex, limiting widespread application.
• The mid-infrared (2.5-7 μm) wavelength region requires specialized polarization optics.

Purpose of the Study:

• To fabricate a cost-effective micropolarizer array for the 2.5-7 μm wavelength region.
• To evaluate the optical performance, including transmittance and extinction ratio.
• To demonstrate compatibility with standard microfabrication processes.

Main Methods:

• Fabrication using reversal nanoimprint and metal evaporation techniques.
• Utilized a unique unit composed of 2x3 arrays on an intrinsic silicon substrate.
• Each array features a 200 nm period bilayer aluminum grating within a 1.3 mm x 1.3 mm aperture.

Main Results:

• Achieved high transmittance (>65%) for transverse magnetic polarization across the 2.5-7 μm range.
• Demonstrated excellent extinction ratios (>35 dB) in specific bands (3-4 μm and 6-7 μm).
• The fabricated micropolarizer array exhibits lower manufacturing costs.

Conclusions:

• The developed micropolarizer array is a viable, cost-effective solution for mid-infrared polarization control.
• The device shows excellent performance metrics suitable for various optical applications.
• The fabrication process is compatible with established microfabrication technologies.