A Holographic Broadband Achromatic Metalens

Abstract

Metalens with nanostructured optical elements are designed to control wavefront shaping at the wavelength‐scale thickness. However, most metalens still suffer from large chromatic aberrations due to phase dispersion, limiting their wide applications for multiple wavelengths. Here, avoiding complex resonant designs or multiple‐layer nanostructures, a simple broadband achromatic metalens by holographic diffraction in the visible spectrum is demonstrated. The hyperbolic phase distributions of multiple discrete wavelengths within a shared aperture and fabricate a broadband achromatic diffractive metalens by flexible direct‐laser‐writing technique is randomly interleaved. The designed polarization‐insensitive metalens modulate the light field by changing the height of the artificial neuron phase units to achieve average focusing efficiencies of 55% in the visible spectrum. This holographic design concept can pave the way to expand achromatic metalenses to multiple spectra.

Recent Applications of Optical Elements in Augmented and Virtual Reality Displays: A Review

“…Figure illustrates representative applications of the metasurface-based optical components in the AR/VR displays. One of the most actively studied metasurface-based optical components in the field of AR/VR displays is the metalens, which imposes a hyperbolic phase profile on the incident light. − In the recent work depicted in Figure a, a holographic broadband achromatic metalens was proposed . The proposed metalens has a lens phase distribution for multiple discrete wavelengths within a shared aperture.…”

“…131−136 In the recent work depicted in Figure 9a, a holographic broadband achromatic metalens was proposed. 131 The proposed metalens has a lens phase distribution for multiple discrete wavelengths within a shared aperture. The approach randomly samples hyperbolic phase distributions at these discrete wavelengths and spatially interleaves them in the aperture to achieve achromatic properties.…”

Design of mid-wave infrared achromatic double-layer metalens with enhanced efficiency

“…Inspired by conventional anti-reflective film, Ryu et al and Basilio-Ortiz et al developed efficient multi-layer dielectric metalenses: one based SOI material for narrow waveband [18] and another using repeatedly stacked GaN/α-Si nanopillars based on Si O 2 substrate in the visible [15]. Numerous studies, employing techniques like dispersion engineering [20][21][22][23][24][25], spatial multiplexing [26][27][28][29], and computational optimization [30][31][32][33], aim to eliminate chromatic aberration in single metalenses. For example, Ou et al demonstrated a broadband achromatic all-Si metalens in the mid-wave infrared, with an average focal efficiency of about 35% [22].…”

Achromatic CMOS-Integrated Four-Bit Orbital Angular Momentum Mode Detector at Three Wavelengths

“…In particular, 3D two-photon nanoprinting has been further demonstrated to engineer dispersion, and the unlocked height degree of freedom enables achromatic focusing across the entire near-infrared telecommunication wavelength band . In addition, a holographic broadband diffractive metalens that enables polarization-insensitive achromatic imaging has been proposed by randomly interleaving the sub-apertures of three different wavelength channels (RGB) …”

“…53 In addition, a holographic broadband diffractive metalens that enables polarizationinsensitive achromatic imaging has been proposed by randomly interleaving the sub-apertures of three different wavelength channels (RGB). 54 Here, we have proposed an achromatic CMOS-integrated OAM mode detector, which can distribute the energies of superposed OAM modes at three distinct wavelengths to the same plane. The conceptual illustration is shown in Figure 1.…”