Overcoming the limits between operational bandwidth, aperture size, and numerical aperture, while expanding their potential in advanced applications, has been a main focus of research. At the same time, with growing demand for better light control, metalenses are gradually moving toward system-level designs. If a single metalens is like a skilled solo player performing in specific situations, then a group of metalenses working together is like a well-practiced orchestra, able to achieve more complex and flexible control of light. In this context, recent progress in metalens technology follows two main paths: one is the ongoing improvement and expanded functions of single metalenses; the other is the continuous development and new applications of multi-metalens systems.

Nanoimprint Lithography (NIL), first introduced in the 1990s by Professor Stephen Y. Chou at the University of Minnesota (later Princeton University), is a novel nanofabrication technology noted for its advantages in low cost, high resolution, and high throughput. The working principle involves directly imprinting mold patterns into polymeric materials, which are either cooled before demolding for thermoplastics or UV cured or thermal set for crosslinkable precursors to precisely replicate nanoscale features. With rapid advancements in science and industry, the demand for precise and efficient fabrication of semiconductor devices, optical components, and biomedical devices has significantly increased, making NIL an indispensable manufacturing method. The year 2025 marks the 30th anniversary of NIL. Through three decades of global efforts, NIL has emerged as the primary alternative to extreme ultraviolet (EUV) lithography for deep-nanoscale silicon electronics. Many semiconductor companies have recognized NIL's manufacturing quality and are actively evaluating its capability in producing advanced semiconductor devices. Moreover, with its high throughput and 3D patterning capabilities, NIL is becoming a key technology for emerging applications such as flat optics and augmented reality glasses, opening new avenues for material research and novel applications.