Broadband silicon polarization beam splitter based on Floquet engineering

Area of Science:

• Photonics
• Integrated Optics
• Materials Science

Background:

• Polarization beam splitters (PBS) are crucial components in optical systems.
• Existing PBS technologies face limitations in bandwidth, size, or performance.
• Silicon photonics offers a scalable platform for integrated optical devices.

Purpose of the Study:

• To propose and demonstrate a broadband silicon polarization beam splitter (PBS).
• To utilize Floquet engineering in directional couplers for enhanced PBS performance.
• To achieve high polarization extinction ratios (PERs) over a wide wavelength range.

Main Methods:

• Designing a PBS based on Floquet-engineered directional couplers.
• Periodically modulating waveguide widths to control mode coupling.
• Experimental fabrication and characterization of the silicon PBS device.

Main Results:

• Demonstrated a compact PBS with a total length of 20 μm.
• Achieved polarization extinction ratios (PERs) >20 dB for both TE and TM modes.
• Observed a broad operational wavelength range from 1483 nm to 1620 nm.
• Measured insertion losses (ILs) of 0.15 dB (TE) and 1.2 dB (TM) at 1550 nm.

Conclusions:

• The proposed Floquet-engineered directional coupler enables efficient broadband PBS operation.
• The silicon PBS demonstrates excellent performance metrics suitable for optical communication systems.
• This work contributes to the advancement of integrated photonic devices for polarization control.