Ultracompact and silicon-on-insulator-compatible polarization splitter based on asymmetric plasmonic–dielectric coupling

Silicon hybrid nanoplasmonics for ultra-dense photonic integration

“…A potential solution is using silicon hybrid nanoplasmonic waveguides locally on the chip with the assistance from low-loss pure dielectric waveguides (SOI nanowires [118]) for long-distance interconnects. This kind of hybrid integration has been used to realize ultrasmall devices [71,[87][88][89][90][91][92]. For example, we proposed a silicon hybrid nanoplasmonic resonant donut with pure dielectric access waveguides [71].…”

“…Particularly, asymmetrical couplers consisting of a silicon hybrid nanoplasmonic waveguide and silicon nanowires has been proposed to realize ultrasmall PBS [87][88][89][90][91]. The PBS length can be even shortened with a MMI coupler proposed in Ref.…”

Compact device employed a hybrid plasmonic waveguide for polarization-selective splitting

“…Recently, we demonstrated an onchip PBS based on directional coupling system consisting of a horizontally slotted waveguide (HSWG) and a HPWG [18], in which only one polarization state was index-matched, whereas the index difference was very high for another polarization so that the effective coupling between the two polarization modes was prevented. Almost at the same time, Gao et al [19] presented an ultracompact PBS consisting of a HPWG and a strip dielectric waveguide, which showed an extinction ratio of over 14.7 dB for the TE-polarized mode within the whole C band. In addition, Lou et al [20] demonstrated a compact PBS based on a dielectrichybrid plasmonic-dielectric coupler.…”

“…As a result, the implementations of polarization beam splitters (PBSs) are essential in the applications of SOI waveguides. Although various configurations, such as multimode interference structures [1][2][3], Mach-Zehnder interferometers [4][5][6], photonic crystal structures [7,8], have been demonstrated to split polarization modes, one would prefer to implement PBSs based on directional couplers [9][10][11][12][13][14][15][16][17][18][19][20][21][22] due to their simplicity and easy design. For instance, Dai et al [14] demonstrated an ultrashort polarization splitter with a strip-nanowire and a vertically slotted waveguide, which took advantage of the completely phase-matching condition for the TM polarization, while significantly suppressed the coupling for the TE polarization.…”

Experimental demonstration of an on-chip polarization splitter in a submicron asymmetric dielectric-coated metal slit

“…In order to realize ultra-compact polarization splitters, the hybrid plasmonic waveguide structures, combining the metal and dielectric structures, were proposed and attracted tremendous attention in recent years. [5][6][7][8][9][10][11][12][13] For example, based on the evanescent coupling effect, the polarization splitters were numerically predicted in the hybrid plasmonic structures, including two coupling dielectric waveguides with a metal nanoribbon, 5 a dielectric-hybrid plasmonic-dielectric coupler, 6 a hybrid plasmonic waveguide coupling with a dielectric waveguide, 7-9 nanoscale silver cylinders sandwiched between two silicon waveguides, 10 and the metal-silica-silicon interactions. 11 The polarization splitters were also numerically investigated in a silicon hybrid plasmonic waveguide 12 based on the multimode interference.…”