Figure 5. (Top, Reflection diffraction efficiency vs. wavelength for a normally incident RHCP planewave) & Figure 6 (Bottom, Reflection diffraction efficiency vs. angle of incidence for a RHCP planewave).
Reflective PVG diffraction behavior for different diffraction angles (20°, 40°, 60°) in glass. The PVG grating tilt angle is set to (10°, 20°, 30°) to achieve the desired diffraction angles of (20°, 40°, 60°). We assume the Bragg wavelength λB = 550 nm at normal incidence, Δn = 0.2 (ne = 1.7, no = 1.5), PVG thickness d = 4 μm, and nglass = 1.57.