Fig. 1. Schematic diagram of diffuse reflection on microstructure

Fig. 2. FDTD simulation analysis model of reflected electrical field of hierarchical microlens

Fig. 3. Distribution of reflected electric field intensity of plane， microprism and hierarchical microlens in different wavebands

Fig. 4. Average intensity of reflected electrical field of smooth plane， microprism and hierarchical microlens

Fig. 5. Experiment devices and schematic diagram of hot embossing hierarchical microlens array

Fig. 6. Micro-optical performance testing equipment and principle

Fig. 7. Surface topography of light guide plate on market

Fig. 8. Surface morphologies of hot-embossed microprism and hierarchical microlens array

Fig. 9. Diffuse reflectance of different microlens arrays versus light wavelength

Fig. 10. Specular reflectance of different microlens arrays versus light wavelength

Fig. 11. Transmittance of different microlens arrays versus light wavelength

Fig. 12. Average illuminance and illumination uniformity of LED with different microlens array LGP

Fig. 13. Average illuminance and illumination uniformity of LED with hierarchical microlens array LGP of versus the aspect ratio of small microlens

Fig. 14. Brightness of LED with screen-printed microdot array LGP and hot-embossed hierarchical microlens array LGP