TiO₂-coated guided-mode resonance gratings for polarization-selective green light filtering

Area of Science:

• Photonics and optical engineering
• Nanotechnology and materials science

Background:

• Dielectric gratings with guided mode resonance (GMR) are crucial for narrow-band optical filtering, offering high diffraction efficiency and sensitivity.
• Polarization-sensitive GMR filters enable selective control of TE and TM mode resonances, expanding their applicability.

Purpose of the Study:

• To theoretically and experimentally investigate polarization-sensitive GMR gratings for green light filtering.
• To demonstrate fabrication methods for high-performance, cost-effective GMR filters.

Main Methods:

• Fabrication of one-dimensional (1D) TiO2-coated GMR gratings with a trapezoidal profile using holographic lithography.
• Utilizing magnetron sputtering for TiO2 coating on photoresist (PR) gratings on SiO2 substrates.
• Employing nanoimprinting for scalable and economical GMR filter production.

Main Results:

• Demonstrated excellent polarization filtering for green light at normal incidence using trapezoidal-profile GMR gratings.
• Achieved high performance with TiO2-coated PR gratings, indicating potential for mass production.
• Verified nanoimprinting as a scalable and cost-effective fabrication technique.

Conclusions:

• Polarization-sensitive GMR gratings are effective for narrow-band green light filtering.
• The demonstrated fabrication methods, including nanoimprinting, offer a pathway for reproducible and economical GMR filter manufacturing.
• These filters have significant potential in telecommunications, spectroscopy, and imaging.