High-Performance Polarization Beam Splitter Based on Shape-Optimized Anti-Symmetric Bragg Gratings

We propose and experimentally demonstrate a high-performance polarization beam splitter (PBS) on silicon-on-insulator (SOI) platform. The PBS integrates a shape-optimized reflective polarizer based on anti-symmetric Bragg gratings with a mode demultiplexer realized through an inverse-designed adiabatic coupler. Experimental results reveal an optical bandwidth of 160 nm (1285 - 1360 nm and 1500 - 1585 nm) with extinction ratio ER > 20 dB, and a narrower bandwidth of 120 nm with ER > 30 dB. The device also features low insertion loss (IL) with ILTE < 1 dB for TE polarization and ILTM < 0.3 dB for TM polarization across the entire operational wavelength range. This PBS stands out as one of the few devices capable of covering the crucial optical bands for fiber-to-the-home (FTTH) networks (1.31, 1.49, and 1.55 μm) while achieving both low IL and high ER. This development marks a significant step forward in polarization diversity for photonic integrated circuits (PIC), supporting next-generation communication systems.