Numerical optimization of wide-angle, broadband operational polarization beam splitter based on aniostropically coupled surface-plasmon-polariton waves

We present the design and optimization of a wide-angle and broadband operational polarization beam splitter by simultaneously satisfying a high reflection of the transverse magnetic (TM) wave and high transmission of the transverse electric (TE) wave using coupled plasmonic waveguides. The finite-difference time-domain (FDTD) method is used in the optimization process where various structural parameters are scanned, and design maps applicable to most III-V material systems are established. Wide-angle operation of over 0° to 70° and ultrabroadband operation over 500 nm with insertion loss less than -1.0 dB are predicted. The extinction ratio is better than - 17 dB, and it is realizable on a chip as small as 0.1 × 2 μm².