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J. Eur. Opt. Society-Rapid Publ. 22, 22( 2026)
Figure
9. Drone show of a hand vs. a gift, Xiamen, China, January 2026( source: authors).
Figure 10. Drone show of Chinese characters, Xiamen, China, January 2026( source: authors).
market was valued at around $ 170 million in 2021 and is expected to grow to $ 719 million by 2028.
3.4.2 Floating 3D display of negative refractive index materials
This technology has revolutionized traditional display and human-computer interaction through its core innovation, the negative refractive index flat lens. By utilizing light field reconstruction, it can reassemble scattered light in the sky to produce real images without a physical medium. With interactive control technology, it allows direct interaction between people and real images in the air. A micro-array structure exhibiting negative refraction properties has been designed, which enables periodic modulation and focusing of the optical path without relying on a curved surface, as shown in Figure 12. All light rays within the light source’ s divergence angle converge to the axis-symmetric position after passing through the flat lens, creating a 1:1 real image and enabling aerial display [ 51 ].
A flat film exhibiting a negative refractive index appears externally as a single sheet of glass but is in fact composed of a dense array of microscopic lenses. The main technical challenge in fabricating such optical glass lies in its highly