Fig. 1. Schematic of the proposed PBS with VDSWs.

Fig. 2. Energy density profiles of TE and TM modes in the 4H-SiC SMWs and the VDSWs. In the simulation, the SMW has a dimension of 400 nm×600  nm, the VDSW has a strip width of 200 nm and a slot width of 100 nm, the refractive index of the SiC is 2.56 and 2.60 for the TE and TM mode, respectively, and the refractive index of the SiO2 is 1.44.

Fig. 3. Simulated results of the transmission efficiency as a function of (a) the coupling length with a side strip width of 200 nm and a slot width of 100 nm, (b) the side strip width with a slot width of 100 nm and a coupling length of 15 μm, and (c) the slot width with a side strip width of 200 nm and a coupling length of 15 μm.

Fig. 4. (a) TE- and (b) TM-polarized light propagation along the optimized PBS.

Fig. 5. Simulated results of (a) transmission efficiency and (b) polarization extinction ratio as a function of wavelength.

Fig. 6. (a) Process flow of the 4H-SiCOI stack fabrication; (b) process flow of the 4H-SiC photonic device fabrication.

Fig. 7. (a) SEM image of the 4H-SiCOI stack; (b) AFM image of the 4H-SiCOI surface topography within an area of 1 μm×1 μm.

Fig. 8. (a) SEM image of the fabricated testing device; (b) zoom-in SEM image of the fabricated VDSW-based PBS.

Fig. 9. Measurement setup schematic. CW, tunable continuous-wave laser; PC, polarization controller; OSA, optical spectrum analyzer.

Fig. 10. Measured results of (a) normalized transmission efficiency and (b) polarization extinction ratio versus wavelength.