Construct Achromatic Polymer Microlens for High‐Transmission Full‐Color Imaging

Abstract

Traditional microlens focuses the beam with spherical convex surface, which achieves high transmission by restraining the scattering loss yet brings spherical aberration and chromatic aberration. While recently‐developed metalens, which relies on phase modulation by elaborately designing local resonators, has realized diffraction‐limited focusing. Yet, the issues of scattering loss of nanoresonators and chromatic aberration remain serious. Here, the design strategies of both metalens and traditional microlens are combined by introducing accurate phase modulation for the wavefront into microlens designing; and a broadband, polarization‐independent, and achromatic microlens with high efficiency is realized. With concentric‐circular polymer (phenolic resin) terrace as basic building blocks, a precise thickness profile is constructed and a high‐index polymer microlens is formed by electron‐beam grayscale lithography. The diffraction‐limited focusing possesses less than 5% change of focal length when the wavelength varies from 425 to 700 nm, showing the full‐color imaging and detection with a focusing efficiency of 80% (at 700 nm wavelength). Moreover, the rotation symmetry of the microstructures of microlens makes it work for arbitrary polarization. The achromatic imaging capability of the microlens is verified by whitelight imaging. It is expected that this high‐efficiency polarization‐independent broadband achromatic polymer microlens may have wide applications in high‐efficient imaging and sensing.

3D-printed multilayer structures for high–numerical aperture achromatic metalenses

“…By using the optimized geometric parameters and the inverse designed structure, we tailored our fabrication process to achieve a stable, multilayer, and high-resolution structures in a short fabrication time of ~1 min for each MAM. Using shrink-compensation (2,3,13,15,16,25,28,47,(51)(52)(53)(54)(55). The color bar and marker size represent the figure or merit defined as the square root of the sum of squares of efficiency, NA, and bandwidth.…”

“…(C) Evolution of focal spots at wavelengths of 400, 533, and 800 nm when additional layers are added (results are from an optimized three-layer design of 0.5-NA MAM). (D) The efficiencies, numerical apertures, and bandwidths (works in the visible band) of various achromatic metalenses (details in tables S1 and S2)(2,3,13,15,16,25,28,47,(51)(52)(53)(54)(55). The color bar and marker size represent the figure or merit defined as the square root of the sum of squares of efficiency, NA, and bandwidth.…”

Large-Area and Rapid Fabrication of a Microlens Array on a Flexible Substrate for an Integral Imaging 3D Display

“…It usually uses a microlens array (MLA) , to record and reconstruct the light field. The performance of the MLA − is a key factor influencing the 3D display parameters such as the resolution, viewing angle, and depth range.…”

Electrically Tunable Bifocal Metalens with Diffraction‐Limited Focusing and Imaging at Visible Wavelengths

“…[ 9 , 10 , 11 , 12 , 13 , 14 ] These planar lenses utilize the power of metasurfaces by manipulating the phase of incident light at the subwavelength scale to produce diffraction limited focusing. [ 15 ] All of the same considerations that exist in conventional optics are still relevant for metalenses, such as the various aberrations, size limitations, and the working bandwidth. A number of high‐performance metalenses have been proposed and experimentally demonstrated to overcome these difficulties.…”