Subwavelength features have been successfully demonstrated in near-field lithography. In this study, the point spread function (PSF) of a near-field beam spot from a plasmonic ridge nanoaperture is discussed with regard to the complex decaying characteristic of a non-propagating wave and the asymmetry of the field distribution for pattern design. We relaxed the shape complexity of the field distribution with pixel-based optical proximity correction (OPC) for simplifying the pattern image distortion. To enhance the pattern fidelity for a variety of arbitrary patterns, field-sectioning structures are formulated via convolutions with a time-modulation function and a transient PSF along the near-field dominant direction. The sharpness of corners and edges, and line shortening can be improved by modifying the original target pattern shape using the proposed approach by considering both the pattern geometry and directionality of the field decay for OPC in near-field lithography.

dimensional periodic structure, namely, the inductive type and the conductive type. [5][6][7] The inductive FSS commonly functions as a band-pass filter that exhibits high transmission at the resonance frequency of the two-dimensional inductive structure. [5,6] By contrast, the conductive FSS exhibits band-stop properties with a strong reflection peak at the resonance frequency. [5,7] In addition to transmission and

Current research on multispectral stealth material technology focuses on practical functionalities such as optical transparency, flexibility, and lightweight. Herein, an optically transparent and single‐layer frequency‐selective surface (OTSF) absorber for dual‐band millimeter‐wave (MMW) absorption and low‐infrared (IR) emissivity is proposed. By adopting indium tin oxide and polyethylene terephthalate, the proposed OTSF absorber exhibits good optical transparency (76% transmittance in the 400–800 nm range on an average) and flexibility. The OTSF absorber exhibits high absorption at the dual‐band frequency in the MMW range (99.7% at 35 GHz and 89.7% at 103 GHz). In the IR band, the average band emissivity of the OTSF absorber for the midwave IR (MWIR) band (3–8 μm) and the long‐wave IR (LWIR) band (8–15 μm) is measured to be 0.26 and 0.23, respectively. Thermal images of the OTSF absorber clearly show its low‐emission characteristics that are similar to those of metal. The proposed OTSF absorber structure has significant potential for practical applications of MMW–IR multispectral stealth materials.

We propose a simple, efficient, and accurate analytical model for calculating the energy efficiency of a granular double-layer X-ray scintillator with a diffuse reflection layer, based on the first-order approximation of the radiative transfer equation by considering boundary conditions and exponential characteristics. Using the analytical model, we successfully analyze the characteristics of the double-layer X-ray scintillator, such as diffuse reflectance, transmittance, collection efficiency, and energy efficiency. We also suggest a design strategy for the high-energy-efficiency X-ray double-layer scintillator considering high diffuse reflectance and satisfaction of the target spatial resolution. Using the X-ray absorption ratio and the collection efficiency of the double-layer scintillator, the energy efficiency of the double-layer X-ray scintillator is calculated to achieve the best performance in terms of image brightness. Through calculation, we obtain the design of a double-layer X-ray scintillator with an energy efficiency of 8.7% with a computation time of less than a second.

No abstract