RESUMEN
A microscope usually consists of dozens of complex lenses and requires careful assembly, alignment, and testing before use. Chromatic aberration correction is a significant step in the design of microscopes. Reducing chromatic aberration by improving optical design will inevitably increase the overall weight and size of the microscope, leading to more cost in manufacturing and maintenance. Nevertheless, the improvement in hardware can only achieve limited correction. In this paper, we propose an algorithm based on cross-channel information alignment to shift some of the correction tasks from optical design to post-processing. Additionally, a quantitative framework is established to evaluate the performance of the chromatic aberration algorithm. Our algorithm outperforms the other state-of-the-art methods in both visual appearance and objective assessments. The results indicate that the proposed algorithm can effectively obtain higher-quality images without changing the hardware or engaging the optical parameters.
RESUMEN
This paper proposes an unwrapping algorithm based on deep learning for inertial confinement fusion (ICF) target interferograms. With a deep convolutional neural network (CNN), the task of phase unwrapping is transferred into a problem of semantic segmentation. A method for producing the data set for the ICF target measurement system is demonstrated. The noisy wrapped phase is preprocessed using a guided filter. Postprocessing is introduced to refine the final result, ensuring the proposed method can still accurately unwrap the phase even when the segmentation result of the CNN is not perfect. Simulations and actual interferograms show that our method has better accuracy and antinoise ability than some classical unwrapping approaches. In addition, the generalization capability of our method is verified by successfully applying it to an aspheric nonnull test system. By adjusting the data set, the proposed method may be transferred to other systems.
RESUMEN
With the development of nanotechnology, it has been accessible to display colors by artificial micro/nano-structure, and then the study of structure coloring has become a hot subject, opening a new space for inkless printing. In this paper, a dynamic color modulation method based on tunable micro/nano-structure array is proposed. To tune colors on the same device, a periodic micro/nano-structure array is designed with functional material inside, which could alter the height difference between up and bottom surface precisely by applying an external voltage. It is modeled, and simulated by the Finite Difference Time Domain (FDTD) method in this work. In simulations, perpendicular incident linearly polarized light source is applied, and parameters of surface height difference and period are swept. Series reflective spectra of the devices are obtained, and their corresponding colors are calculated and marked on the CIE 1931 chromaticity diagram. Simulation results demonstrate that when the period is in the range of 100-300 nm, full-color modulation could be realized by varying the height of functional material film via applied voltage, and the peak intensities of reflective spectra are at about 60%, having high energy efficiency. This method is innovative and provides a theoretical basis for the dynamic color modulation micro/nano device, which is quite promising in fields like inkless printing and display technology.
RESUMEN
This article reports a novel color tuning method by local sputtering nanolayers on microstructured porous alumina (PA) templates with different pore depths. With the aid of scanning electron microscopy observation, physical models of the original and sputtered PA templates are set up, and the details of the color tuning method are further proposed. Two series of colors covering the whole visible range are first obtained by respectively sputtering Cr and Ag nanolayers on two groups of PA templates with pore-depths ranging from 230 to 490 nm. A vivid colorful pattern of "Butterfly wings" is then prepared by local sputtering such Cr and Ag nanolayers on the surface of a PA with 310 nm pore-depth. The scanning electron microscopy images of Cr and Ag sputtered PA surfaces show different microstructures, which is in agreement with different color exhibiting. This method is expected to have a potential of being widely applied in the fields of micro-optics, microstructures, advanced materials, and micro/nanotechnology.
RESUMEN
A simple and effective color tuning method has been developed by controlling the pore depth of the metal-coated porous alumina (PA) template. The mechanism for color tuning in this method was uncovered, which can be used to design a colorful complex pattern. A colorful 'world map' was produced and exhibited on a PA template by this method. Such vivid color tuning is predominantly due to the interference enhancement of the nanostructure. This method has the potential for tuning colors and being widely applied in the fields of nanotechnology, physics and photonics.
