Fig. 1. Curve of equivalent refractive index of Al metal grating with wavelength

Fig. 2. Structure model of metal polarization beam splitting grating

Fig. 3. FDTD structure simulation model

Fig. 4. Curves of diffraction efficiency and extinction ratio with grating period

Fig. 5. Curve of diffraction efficiency and extinction ratio with the height of grating ridge

Fig. 6. Curves of extinction ratio with incident angle calculated by different algorithms

Fig. 7. Curves of extinction ratio with incident wavelength calculated by different algorithms

Fig. 8. Extinction ratio test diagram

Fig. 9. Extinction ratio test diagram at 0.632 8 µm

Fig. 10. Extinction ratio test curve at broad wavelengths

Fig. 11. Comparison of extinction ratio test and simulation with an incident wavelength of 0.632 8 µm