Compact and fabrication-tolerant polarization splitter based on horizontal triple-slot waveguide

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Waveguide Devices

Background:

• Polarization beam splitters (PBS) are fundamental components in optical systems.
• Existing PBS designs often face challenges with compactness and fabrication tolerance.
• Horizontal triple-slot waveguides offer a promising platform for novel photonic devices.

Purpose of the Study:

• To propose and optimize a compact and fabrication-tolerant polarization beam splitter (PBS).
• To utilize horizontal triple-slot waveguides for enhanced PBS performance.
• To rigorously analyze the performance and fabrication tolerances of the proposed PBS.

Main Methods:

• Rigorous H-field-based full-vectorial finite element method (FEM) for electromagnetic field analysis.
• Least-squares boundary residual method for optimizing device parameters.
• Detailed simulation and analysis of optical performance and fabrication tolerances.

Main Results:

• A compact PBS with a length of 33 μm was successfully designed.
• High polarization extinction ratios of -21.8 dB (quasi-TE) and -20.3 dB (quasi-TM) were achieved at 1.55 μm.
• A 1 dB bandwidth of 100 nm was obtained for both polarizations, indicating broad operational range.
• Fabrication tolerances were thoroughly investigated and quantified.

Conclusions:

• The proposed horizontal triple-slot waveguide PBS offers a compact and robust solution.
• The device exhibits excellent performance metrics, including high extinction ratios and broad bandwidth.
• The design shows significant potential for integration into various photonic applications demanding efficient polarization control.