In this paper, an effective method for fabricating artificial compound-eye structures is demonstrated. The fabrication of high fill factor microlens arrays (MLAs) with sub-wavelength structures (SWSs) on a polycarbonate (PC) substrate involves nanoimprint and thermo-extrusion techniques by using two different scales of nano/micromolds. In addition, the MLAs with SWSs on the PC substrate would be replicated on a polymethylmethacrylate (PMMA) millimeter concave surface by hot-embossing, forming three-level compound-eye structures. The optical properties of these samples are characterized. The transmittances of two-level PC and three-level PMMA compound structures are increased by 2.5% and 2%, and the uniformities are enhanced by 18% and 24%, respectively.
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http://dx.doi.org/10.1088/0957-4484/22/21/215303 | DOI Listing |
ACS Mater Au
January 2025
Liquid Crystal Research Laboratory, Department of Physics, University of Lucknow, Lucknow, Uttar Pradesh 226007, India.
Polymer-dispersed liquid crystals (PDLCs) stand at the intersection of polymer science and liquid crystal technology, offering a unique blend of optical versatility and mechanical durability. These composite materials are composed of droplets of liquid crystals interspersed in a matrix of polymeric materials, harnessing the optical properties of liquid crystals while benefiting from the structural integrity of polymers. The responsiveness of LCs combined with the mechanical rigidity of polymers make polymer/LC composites-where the polymer network or matrix is used to stabilize and modify the LC phase-extremely important for scientists developing novel adaptive optical devices.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Bio and Brain engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
Nocturnal and crepuscular fast-eyed insects often exploit multiple optical channels and temporal summation for fast and low-light imaging. Here, we report high-speed and high-sensitive microlens array camera (HS-MAC), inspired by multiple optical channels and temporal summation for insect vision. HS-MAC features cross-talk-free offset microlens arrays on a single rolling shutter CMOS image sensor and performs high-speed and high-sensitivity imaging by using channel fragmentation, temporal summation, and compressive frame reconstruction.
View Article and Find Full Text PDFUltramicroscopy
March 2025
Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China. Electronic address:
Microlens array (MLA), through which all the sub-beams are focused, is widely used in multi-electron-beam systems. In this work, based on the differential algebraic (DA) method, we propose an approach in calculating the high-order aberrations for both axial and off-axial microlenses, considering the multipole fields that are introduced by the neighborhood structures in MLA, as well as the rotationally symmetric field. To perform the DA calculation, the electric fields of the microlenses are analyzed by using the azimuthal Fourier analysis and the Fourier-Bessel series Expansion.
View Article and Find Full Text PDFNanophotonics
August 2024
Department of Electronic Engineering and Department of Artificial Intelligence and Department of Artificial Intelligence Semiconductor Engineering, Hanyang University, Seoul, 04763, South Korea.
Over the past decade, significant advancements in high-resolution imaging technology have been driven by the miniaturization of pixels within image sensors. However, this reduction in pixel size to submicrometer dimensions has led to decreased efficiency in color filters and microlens arrays. The development of color routers that operate at visible wavelengths presents a promising avenue for further miniaturization.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Laboratory for Chemistry and Life Science, Institute of Integrated Research, Institute of Science Tokyo, R1-12, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan.
The photoinduced molecular reorientation of liquid crystals (LCs) caused by their nonlinear optical responses has attracted much attention due to their large refractive index change, leading to promising applications in optical devices. This reorientation is typically induced by light irradiation above a threshold intensity and is temporary, with the initial orientation recovering unless the LCs are polymerized and cross-linked. Our report highlights the memory effect of molecular reorientation in LCs.
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