This work investigates a polarization-independent and fast response microlens array. This array is composed of a concave polymer microlens array and blue phase liquid crystals (BPLCs). The microlens array can be either positive or negative, depending on the birefringence of the BPLCs. The experimental results show that the microlens array is fast switched between positive and negative focal lengths via controlling the electric fields, and the response time is a few hundred microseconds. Additionally, the focusing efficiency is independent of the polarization of the incident light.
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http://dx.doi.org/10.1364/OE.22.000925 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Dalian University of Technology State Key Laboratory of High-Performance Precision Manufacturing, Key Laboratory for Micro/Nano Technology and System of Liaoning Province, School of Mechanical Engineering, Dalian 116024, China.
Inspired by ancient trilobites, novel curved microlens arrays (CMLAs) were designed. Direct, fast, and low-cost CMLAs with two focal planes were fabricated using ultraprecision machining technology and hot embossing technology. We designed four pairs of artificial compound eyes (ACEs) composed of large and small lenses with four different curvatures to achieve focusing and imaging on two focal planes.
View Article and Find Full Text PDFFourier ptychographic microscopy (FPM) enables high-resolution, wide-field imaging of both amplitude and phase, presenting significant potential for applications in digital pathology and cell biology. However, artifacts commonly observed at the boundaries of reconstructed images can significantly degrade imaging quality and phase retrieval accuracy. These boundary artifacts are typically attributed to the use of the fast Fourier transform (FFT) on non-periodic images.
View Article and Find Full Text PDFACS 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.
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