Ultracompact polarizing beam splitter based on single-material birefringent photonic crystal

Area of Science:

• Photonics
• Materials Science
• Optical Engineering

Background:

• Polarizing beam splitters (PBS) are crucial optical components for manipulating light polarization.
• Existing PBS technologies often face limitations in size, fabrication complexity, or performance.
• Developing miniaturized and high-performance PBS is essential for advanced optical systems.

Purpose of the Study:

• To design and fabricate an ultracompact polarizing beam splitter (PBS).
• To utilize a single-material birefringent photonic crystal structure for PBS fabrication.
• To achieve high polarization separation efficiency in a minimal device footprint.

Main Methods:

• Employed e-beam physical vapor deposition with oblique angle deposition.
• Created a birefringent photonic crystal using alternating titanium dioxide layers with different refractive indices.
• Deposited titanium dioxide at angles of 0° and 70° to form the structure.

Main Results:

• Successfully designed and fabricated an ultracompact PBS with a total device length under 6 micrometers.
• Achieved efficient separation of two polarization states with efficiencies exceeding 92%.
• The design demonstrates high tolerances suitable for volume production.

Conclusions:

• A novel, ultracompact PBS based on a single-material birefringent photonic crystal has been demonstrated.
• The fabrication method allows for high-performance devices with a significantly reduced footprint.
• This technology offers a promising solution for miniaturized optical systems requiring precise polarization control.