Challenges and opportunities of metalenses

Metalenses are poised to redefine optical design, but their path from laboratory innovation to real-world application remains fraught with both remarkable promise and persistent challenge. Enabled by subwavelength nanostructures, these flat optical components promise to revolutionize photonics by replacing bulky conventional optics with compact, multifunctional devices. However, persistent trade-offs among numerical aperture, focusing efficiency, spectral bandwidth, field of view and device size continue to constrain their versatility. Overcoming these bottlenecks will rely on the convergence of design innovation, material breakthroughs and scalable manufacturing. Recent advances in large-area nanofabrication, high-aspect-ratio patterning and advanced material integration are beginning to alleviate these limitations, signalling a path toward scalable, high-performance and multifunctional metalenses. As advances in nanofabrication and design accelerate worldwide, stronger synergy between academic research and industrial development has become essential to transform current challenges into opportunities for the widespread adoption of metalenses in real-world optical systems.