Ultracompact Polarization Splitter-Rotator Based on Shallowly Etched Subwavelength Gratings and Anisotropic...

Area of Science:

• Photonics
• Nanotechnology
• Materials Science

Background:

• Polarization splitter-rotators (PSRs) are crucial for on-chip polarization-sensitive and polarization-division multiplexing systems.
• Efficient and compact PSRs are needed to advance integrated photonic devices.

Purpose of the Study:

• To propose and demonstrate an ultracompact, high-performance silicon-based PSR.
• To utilize anisotropic metasurfaces for novel polarization management.

Main Methods:

• Design of a silicon-based PSR utilizing tilted periodic anisotropic metasurfaces.
• Electromagnetic simulations to analyze performance characteristics at 1.55 μm wavelength.

Main Results:

• Achieved an ultracompact device length of ~13.5 μm.
• Demonstrated low TE-to-TM conversion loss (-0.154 dB) and high polarization conversion ratio (96.5%).
• Reported excellent crosstalk (-27.0 dB) and reflection loss (-37.3 dB) for TE input, and low insertion loss (-0.19 dB) for TM input.

Conclusions:

• The proposed anisotropic metasurface enables ultracompact and high-performance PSRs.
• The device exhibits a wide operational bandwidth (~112 nm) and good fabrication tolerance.
• This work offers a promising solution for polarization management in integrated photonics.