Compact high-performance silicon-on-insulator polarization beam splitter for ultra-broadband photonic applications

Abstract

Abstract This study discusses a polarization beam splitter that efficiently separates transverse electric (TE) and transverse magnetic (TM) polarizations across the L, C, S, and E (1.4–1.625 µ m) optical bands, with operation extending up to 1.7 µ m, to illustrate the device’s broader wavelength response, achieving a wide operational bandwidth exceeding 200 nm. The device, implemented on a silicon-on-insulator platform, features an optimized coupling length of only 4 µ m, the shortest reported for such a wide operating range. It achieves extinction ratios (ERs) over 24 and 20 dB for the TM and TE modes, respectively, across a specified bandwidth, while maintaining low insertion losses (ILs) below 0.85 dB for the TM mode and 0.04 dB for the TE mode. Additionally, the design can be adapted for TE/TM-pass polarizer operation, achieving ERs of 25 dB (TE-pass) and 30 dB (TM-pass) with ILs as low as 0.035 and 0.1 dB. These results highlight the potential of the proposed geometry for integration in high-performance polarization-handling photonic circuits.