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Metasurface‐based flat optics has a great potential to replace conventional bulky and heavy optical elements, consistent with the trend of miniaturizing optical elements. One of the trends is to broaden the operating area of the metasurface. The previous approaches are focused on expanding the metasurface area, which has intrinsic manufacturing and optical limitations. Here, this work presents the fabrication of wafer‐scale metalens arrays, and demonstrates the Gabor superlens composed of the metalens arrays, which behaves optically like a large lens system. A pair of fabricated 8‐inch‐sized metalens arrays are used to float the large‐area display, producing a real image in the air. This superlens is easily manufactured in a high‐throughput and cost‐effective manner using an argon fluoride dry scanner and a single reticle. Their capability for diffraction‐limited focusing and imaging is demonstrated. Considering the groundbreaking nature of imaging a large‐area display through the metalens arrays, this work shows a great potential for scaling up the optical display systems in a simple manner. [ABSTRACT FROM AUTHOR]

Metalenses have revolutionized optical technologies with their superior ability to manipulate light and the potential to replace conventional, bulky optical components. However, their commercialization is hindered by limitations in conventional manufacturing techniques, such as small patterning areas, low throughput, and high cost. In this study, two methods are introduced for scalable and wafer‐scale manufacturing of metalenses operating in the near‐infrared region, aimed at overcoming the abovementioned challenges. The first type of metalens is polarization‐independent and constructed using hydrogenated amorphous silicon cylindrical structures fabricated through direct photolithography. This metalens has a diameter of 1 cm and numerical aperture (NA) of 0.53. The focusing efficiency is confirmed at a 940 nm wavelength, and the focal spot profile approaches the diffraction limit. The second metalens is polarization‐dependent and fabricated using silicon nanoparticle‐embedded‐resin rectangular structures through a cost‐effective nanoimprinting method. This process can produce metalenses with a diameter of 5 mm and an NA of 0.53. Both types of metalenses demonstrate high‐resolution capabilities when imaging a 1951 USAF resolution test target and bioimaging. This research offers innovative pathways for the mass production and large‐scale fabrication of metalenses. It is believed that the work will accelerate the industrialization of metalenses, fostering further advances in optical technology. [ABSTRACT FROM AUTHOR]

Metasurfaces, which are designed by arranging meta‐atoms, have attracted attention for their ability to create optical properties that do not exist in nature. However, previous methods for fabricating metasurfaces using electron‐beam lithography (EBL) are expensive and have limited production capacity, inhibiting mass production. In this study, a new manufacturing method is demonstrated using an argon fluoride (ArF) scanner and nanoimprint lithography (NIL) to overcome these limitations. 266 millimeter‐scale metasurfaces are designed and fabricated on an 8‐inch wafer using an ArF scanner. Subsequently, this is used as a master stamp to replicate the metasurfaces in an 8‐inch wafer scale through the NIL process all at once. To demonstrate the effectiveness of this method, a metahologram is designed and manufactured using TiO2 nanoparticle‐embedded‐resin (nano‐PER). The metahologram achieves an 81.2% yield during replication, with a maximum efficiency of 60.7% at 450 nm, 45.1% at 532 nm, and 38.5% at 635 nm, respectively. The results demonstrate the production of practical metaholograms using low‐cost and high‐throughput processes. [ABSTRACT FROM AUTHOR]

Metalenses comprised of artificial subwavelength structures known as meta-atoms have demonstrated abilities beyond conventional bulky optical components by modulating the phase, amplitude, and polarization of light in an ultrathin planar form factor. In this Tutorial, we present the fundamental principles and practical design procedures to exploit the abilities of metalenses, including achromaticity, high numerical aperture, and tunability. The fundamental principles include both plasmonic and dielectric meta-atoms, which require different physics to describe their light–matter interactions. In the phase modulation section, we compare the methods of physically implementing phase via meta-atoms including both the propagation and geometric phase methods. Next, we cover the recent progress of nanofabrication procedures from the perspective of the metalenses using materials such as titanium dioxide, gallium nitride, and hydrogenated amorphous silicon. We further compare the various fabrication methods with regard to the resolution, size, cost, and optical properties of fabricated metalenses. Then, we describe the critical considerations of metalenses including aberration-correction, numerical aperture, and tunability for advanced flat optics. Herein, we provide a practical guide for the design, fabrication, and critical considerations of metalenses with examples of research from early works to more recent developments. [ABSTRACT FROM AUTHOR]

Donor–acceptor (D–A) type molecules with a skeleton consisting of a dimethylaminonaphthalene donor and an oxazaborine acceptor were designed as efficient electrochemiluminescence (ECL) luminophores with tunable intramolecular charge transfer (ICT). The D–A ECL luminophores demonstrated that the ICT characteristics play a critical role in the electrochemistry and ECL of luminophores in the presence of tri-n-propylamine, which was rationalised experimentally and computationally. Furthemore, dual-peaked ECL-potential behaviours of the luminophores were rationalised using two competitive pathway ECL mechanisms, elucidated through the use of spooling ECL spectroscopy. [ABSTRACT FROM AUTHOR]

To achieve the high tunability and quantum yield of carbon dots (CDs) suitable for applications to bioimaging and optoelectronic devices, optical features are systematically investigated in three types of CDs. Phenylenediamine isomers are employed to develop the CDs of blue, green, and red. Despite the comparable chemical structures and functional groups, the predominant optical transitions are distinct in the three CDs, which is mainly attributed to the configurations of fluorophores in aggregated structures. Another type of optical transition is also observed, whose energies are similar in the three CDs, implying the involvement of surface states. The first-principles calculations indicate that the functional groups change the electronic structures and transition energies, suggesting that oxidation-related states are responsible for the surface states. In a wide range of pH, the optical transitions remain stable, although the protonated chromophores result in shifted transitions in highly acidic conditions. The protonation of the nitrogen moiety influences the electronic structures, while the protonated position controls the relaxation processes. These findings offer strategies to improve the multicolor CDs with a green chemistry approach, which are suitable for applications to bioimaging and optoelectronic devices as alternatives to metal-based semiconductor quantum dots. [ABSTRACT FROM AUTHOR]