Experimental demonstration of a SiN integrated polarization beam splitter for the 950 nm wavelength band

Silicon Nitride photonic integrated circuits are highly sought after for quantum applications. This platform offers ultra-low propagation losses, reduced birefringence, and a wide transparency window. This study presents the design and experimental demonstration of a compact silicon nitride polarization beam splitter (PBS) for the 950 nm wavelength range. The PBS employs cascaded tapered asymmetric directional couplers to achieve efficient polarization control. With insertion losses below 1 dB, polarization extinction ratios exceeding 19 dB (TE) and 10 dB (TM), and operation from 920 nm to 970 nm, it offers promising integration into photonic systems requiring precise polarization manipulation.