Fig. 1. Principle of the directional backlighting 3D display^[14]

Fig. 2. Directional backlighting 3D display system proposed by Eun-Soo Kim's team^[19]. (a) Principle; (b) principle of the backlight; (c) (d) results

Fig. 3. Directional backlighting 3D display system proposed by Jianying Zhou's team^[21-22]. (a) Principle; (b) partial detailed structure for the backlight; (c) (d) results

Fig. 4. Directional backlighting 3D display system proposed by Xu Liu's team^[25].(a) Principle; (b) prototype; (c) results

Fig. 5. Principle of compressive light field display

Fig. 6. Compressive light field display system proposed by Byoungho Lee's team. (a) Principle; (b) results

Fig. 7. Compressive light field display system proposed by Guoqiang Lü's team^[37]. (a) Principle; (b) prototype; (c) results

Fig. 8. Compressive light field display system with large depth-of-field proposed by Xu Liu's team^[38]. (a) Principle; (b) results

Fig. 9. Compressive light field tracking display system proposed by Xu Liu's team^[40-41]. (a) Principle; (b) results

Fig. 10. Retinal optimization and foveated rendering pipeline for compressive light field display system proposed by Xu Liu's team^[42-43]. (a) Retinal sampling map; (b) foveated rendering pipeline; (c) results

Fig. 11. Principle of integral display. (a) Integral photography; (b) integral imaging

Fig. 12. Simulated results of integral imaging display system proposed by Xinzhu San's team^[50].(a) Conventional DOE Fresnel lens; (b) optimized DOE lens

Fig. 13. HOE & PDLC-based integral imaging display system proposed by Qionghua Wang's team^[53]. (a) Principle; (b) prototype; (c) 2D display result; (d) 3D display results

Fig. 14. Liquid crystal micro-lens array based integral imaging display system proposed by Qionghua Wang's team^[54]. (a) Principle; (b) results

Fig. 15. Integral imaging tracking display system proposed by Bahram Javidi's team^[55]. (a) Principle; (b) prototype; (c) results

Fig. 16. Integral imaging tracking display system proposed by Qionghua Wang's team^[56]. (a) Principle; (b) prototype; (c) results

Fig. 17. Integral imaging tracking display system proposed by Nippon Hoso Kyokai'team^[57]. (a) Principle; (b) prototype; (c) results

Fig. 18. Scalable light field display system based on multi-LCDs proposed by Xu Liu's team^[66]. (a) Prototype; (b) principle; (c) results

Fig. 19. Spatial multiplexing directional light field display system proposed by Wen Qiao's team^[71].（a）Schematic of spatial multiplexing；（b）prototype；（c）SEM image of three layers of metagratings with one subpixel；（d）-（f）results

Fig. 20. Foveated glasses-free 3D display system proposed by Wen Qiao's team^[73]. (a) Principle; (b) photo of the view modulator; (c) prototype; (d) results