Silicon-based polarization beam splitters with broadband subwavelength grating TM-pass polarizers

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• Polarization beam splitters (PBSs) are essential for controlling light polarization in photonic integrated circuits.
• Existing PBS designs often face limitations in bandwidth, footprint, or fabrication complexity.

Purpose of the Study:

• To demonstrate a novel silicon-based PBS.
• To integrate a broadband subwavelength grating (SWG) TM-pass polarizer for enhanced performance.
• To achieve a balance between performance, size, and manufacturability.

Main Methods:

• Design and fabrication of a silicon-based PBS incorporating an SWG TM-pass polarizer.
• Experimental characterization of insertion loss (IL) and crosstalk (CT) across a specified wavelength range.
• Integration compatibility assessment with standard silicon photonics platforms.

Main Results:

• Achieved insertion loss below 1 dB for both TE and TM polarizations.
• Demonstrated crosstalk below 30 dB over the 1500 nm to 1561 nm wavelength range.
• Verified compatibility for integration within silicon photonics platforms.

Conclusions:

• The novel silicon PBS with SWG TM-pass polarizer offers excellent performance metrics.
• The device presents a viable solution for polarization management in integrated photonics.
• The design provides a good trade-off between bandwidth, footprint, and fabrication ease.