Based on a silicon-on-insulator (Silicon-on-insulator, SOI) material system design and optimization of a high performance, the polarization independent of 1 × 3 subwavelength grating stars beam splitter. By a rigorous coupled-wave analysis method showed that, in the 1550nm wavelength range, at vertical incidence, the device on the transverse electric field (transverse electric, TE) ,the 0 and ± 1 order transmittance is 31%, 32%, 32%,respectively; cross the magnetic field (transverse magnetic, TM), the 0 and ± 1 transmittance is 33%, 32%, 32%, respectively.
A new structure of microstructure reflection three-port beam splitter grating is described in this paper. The grating includes two dielectric layers and a metal slab on the substrate, where incident waves are reflected into the zeroth-order and the ± first-order with polarization-independent property. With the optimized grating profile, reflection efficiencies’ ratios between the first-order and the zeroth-order can reach 0.998 and 1.001 for TE and TM polarizations, respectively. Especially, the reflection grating can diffract efficiencies more than 30% into the ± first-order and the zeroth-order with the incident angular bandwidth of −1.9–1.9[Formula: see text] for TM polarization, which can have merits compared with single-layer transmission grating.
A Plasmonic based Ultracompact Polarization Beam Splitter on Silicon-on-Insulator Waveguides
