Silicon-Based Ultracompact TE-Pass/TM-Stop Power Divider Using Subwavelength Gratings Assisted With Segmented Hybrid Plasmonic Horizontal Slot Waveguides

A silicon-based ultracompact TE-pass/TM-stop power divider is proposed and analyzed in detail. By using subwavelength grating (SWG) structures, for injected TE mode, a twofold image in a SWG multimode waveguide is formed and then equally divided into two output channels. As to the injected TM mode, it is radiated into the claddings with the help of three segmented hybrid plasmonic horizontal slot waveguides (HPHSWs), located above the bottom strip and SWG waveguides. Consequently, both equal-power splitting and polarization selection can be realized in the present single device, beneficial to realization of dense integration in photonic-integrated circuits. Moreover, to enhance the device performance, tapered HPHSWs above the SWG structure are used. Results show that a compact device of 4.25 μm in total length is achieved with an insertion loss (IL) of 0.28 dB (TE), an extinction ratio (ER) of 19.73 dB, and a reflection loss of -28.13 dB (-19.69 dB) for TE (TM) mode. The bandwidth is up to 118 nm when the ER is over 15 dB and IL is below 0.4 dB. In addition, fabrication tolerances to the structural parameters are investigated detail and field evolution along the propagation distance through the proposed device is also presented.