Fig. 1. (a) Cross-sectional view of the proposed InGaN/GaN LED featuring integrated metasurfaces on both sides; (b) propagation and polarization conversion mechanisms of the TM- and TE-polarized components within the integrated structure.

Fig. 2. (a) Variation of phase difference (Δφ) with width W₂ and height H₄; (b) variation of amplitude ratio (|E_x|/|E_y|) with width W₂ and height H₄; (c) transmittance at varying heights and widths. Simulation parameters: P₂ = 250 nm, W₂ = 75 nm, and H₄ = 110 nm.

Fig. 3. (a) Phase difference (Δφ) and amplitude ratio (|E_x|/|E_y|) of the AMNG structure vary as a function of wavelength. (b) Reflectance of the AMNGs varies as a function of wavelength. Simulation parameters: P₂ = 250 nm, W₂ = 75 nm, and H₄ = 110 nm.

Fig. 4. (a) SEM of the fabricated structure of BMNGs with a period of 150 nm (uncoated). Inset, cross-section of PMMA grating structure. (b) Top view and cross-sectional view (inset) of the sapphire grating structure.

Fig. 5. (a) Measurement principle diagram of the integrated GaN-based LED device; (b) EL spectrum at room temperature for GaN-LED devices with the AMNG structure on the top emission surface and the BMNG metasurface structure on the sapphire substrate’s backside, under a forward current of 100 mA. (c) EL green luminescence intensity of GaN-based LEDs featuring asymmetric metasurfaces integrated on both upper and lower surfaces at various θ; (d) ER results for the integrated device and two comparative devices.

Fig. 6. (a) Results of micro-LEDs exposed to unpolarized light irradiation; (b) micro-LED imaging results obtained by utilizing a polarization light source in conjunction with a polarization analyzer; (c) polarization imaging results of the micro-LED device with electrode damage.