Fig. 1. (a) 3D view of the proposed on-chip all-silicon polarizer utilizing the AM with some key parameters labeled. The white dashed line shows the optical axis orientation of the SWG metamaterial. (b) The enlarged top view of the input section with some key parameters labeled; (c) calculated extraordinary (ne) and ordinary (no) effective refractive indices for the SWG metamaterial with varied duty cycle f; (d) working principle for the metamaterial-assisted polarizer. For TE polarization, the SWG effective refractive index is extraordinary (neffTM≈n∥=ne), which is much smaller than the silicon refractive index, leading to the confined mode and negligible bending loss, so the incident TE mode will propagate through the sharp bend. For TM polarization, the SWG effective refractive index is ordinary (neffTM≈n⊥=no), which is close to the silicon refractive index, leading to the leaky mode and strong bending loss, so the incident TM mode will be coupled into the radiation mode.

Fig. 2. Calculated transmittance spectra for TE and TM modes with varied maximum SWG duty cycle (fM) and bending radius (R0).

Fig. 3. Calculated (a) EL and (b) PER spectra with varied SWG period number (N).

Fig. 4. (a) Calculated TE and TM light propagation profiles for the optimized polarizer at three different wavelengths (λ=1.26, 1.55, 1.675 μm). The calculated transmittance spectra for the (b) optimized polarizer with full structure, (c) optimized polarizer with effective medium equivalence, and (d) waveguide bend without SWG cladding.

Fig. 5. Calculated transmittance spectra for the metamaterial-assisted polarizer with deviated parameters.

Fig. 6. (a) Microscope image of the fabricated devices; (b) SEM image of the fabricated metamaterial-assisted polarizer. The measured transmittance spectra over (c) O-, E-bands and (d) S-, C-, L-, U-bands.

Fig. 7. (a) Microscope image of the cascaded polarizers. The measured single polarizer EL spectra over (b) O-, E-bands and (c) S-, C-, L-, U-bands.

Fig. 8. Calculated TM mode transmittance spectra with varied SWG period number (N) and minimum SWG duty cycle (fm).

Fig. 9. (a) Configuration of the GC with some key parameters labeled; (b) measured EL spectra for the fabricated GCs with different fiber probe tilt angles θfiber.