Roll-to-plate printable RGB achromatic metalens for wide-field-of-view holographic near-eye displays

Abstract

Metalenses show promise for replacing conventional lenses in virtual reality systems, thereby facilitating lighter and more compact near-eye displays (NEDs). However, at the centimetre scale necessary for practical applications, previous multiwavelength achromatic metalenses have faced challenges in mass production and exhibited a low numerical aperture (NA), which limits their practical application in NEDs. Here we introduce a centimetre-scale red, green and blue achromatic metalens fabricated using a roll-to-plate technique and explore its potential for practical applications in NEDs. This metalens is designed through topological inverse design utilizing a finite-difference time-domain simulation for entire areas (~10,000λ). Our design method demonstrates the ability to compensate chromatic aberrations even at the centimetre scale and high NA with low-index materials such as resin suitable for scalable manufacturing. In addition, we developed a compact NED by integrating the metalens with computer-generated holography (CGH). In this NED system, the high-NA metalens address the limitations of narrow field of view and extensive empty space typical of conventional CGH-based NEDs. The CGH optimization model further resolves the challenges of broadband operation and off-axis aberration in centimetre-scale red, green and blue achromatic metalenses. Using a topological inverse design process with finite-difference time-domain simulations, the authors fabricate high-numerical-aperture red, green and blue achromatic metalenses for compact near-eye displays using a scalable roll-to-plate technique.