Broadband iridium wire grid polarizer for UV applications

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Wire grid polarizers are crucial optical components.
• Achieving sub-wavelength grating periods for UV applications presents significant fabrication challenges.

Purpose of the Study:

• To present an iridium wire grid polarizer with a wide spectral working range, extending from the infrared (IR) to the ultraviolet (UV) region.
• To demonstrate a fabrication method enabling the required 100 nm grating period for UV operation.

Main Methods:

• Utilized ultrafast electron beam writing to achieve a 100 nm grating period.
• Employed a spatial frequency doubling technique for high-resolution patterning.
• Fabricated an iridium wire grid polarizer.

Main Results:

• The polarizer exhibits a large spectral working range from IR to UV.
• Optical performance at 300 nm includes a transmittance of nearly 60% and an extinction ratio of approximately 30 (15 dB).
• The oxidation resistance of the iridium polarizer was evaluated.

Conclusions:

• The developed iridium wire grid polarizer successfully operates across a broad spectral range, including the UV region.
• The fabrication technique is effective for creating sub-wavelength gratings necessary for UV polarizers.
• The polarizer demonstrates promising optical performance and material stability for demanding applications.