A trench-assisted multicore fiber (TA-MCF) with single-supermode transmission and nearly zero flattened dispersion is proposed herein. By adding a simplified microstructure cladding with only one ...ring of low-index inclusions on the basis of the multicore fiber, the microstructure cladding and mode-coupling mechanism were jointly employed into the TA-MCF to modulate light transmission. This guarantees that the TA-MCFs had sufficient capability for wideband dispersion management when only pure, germanium-doped, and fluorine-doped silica glass with low index differences were chosen to form the TA-MCF. Analyses also revealed that the TA-MCFs have the merits of shorter cut-off wavelength and flatter-top optical intensity distribution compared with traditional multicore fibers. After the investigation of the structural parameters’ influences on the dispersion of the fundamental supermode, two TA-MCFs with single-supermode transmission and nearly zero flattened dispersion were designed. For the seven-core TA-MCF, the dispersion varying from −0.46 to 1.35 ps/(nm·km) in the wavelength range of 1.50 to 2.04 μm, with bending loss as low as 0.085 dB/km and 35-mm bending radius at 1550 nm was achieved with index difference less than 0.015. The TA-MCFs proposed herein have the advantages of being a quasi-single material, with an all solid scheme and simplified structure.
An all solid quasi-single material microstructure fiber (AS-QSM-MSF) with flattened dispersion and single mode transmission is presented in this paper. Besides microstructured cladding, six-core ...configuration is also employed to incorporate mode coupling mechanism into light transmission control in our proposed fiber. By doing this, flattened dispersion in the range of − 1.03–0.75 ps/(nm km) can be achieved from 1.52 to 2.01 μm, while refractive index difference Δ
n
between matrix and doped inclusions is less than 0.016. Numerical results also show that the fundamental supermode has a flat top power density distribution with effective mode area 48.4 μm
2
at 1.55 μm. Compared with the fibers of Gaussian power distribution, our fiber has a more uniform power distribution, which means that our fiber is less susceptible to nonlinear effect under same input power and effective mode area. In addition, simulation results show that the proposed AS-QSM-MSF has a wide single mode regime with cutoff wavelength at 1.197 μm. And the confinement loss and bending loss of the fiber at 45 mm bending radius are as low as 2.6 × 10
−7
dB/km and 9.7 × 10
−2
dB/km at 1.55 μm, respectively.
The study of the origin of asymmetries in mirror β decay is extremely important to understand the fundamental nuclear force and the nuclear structure. The experiment was performed at the National ...Laboratory of Heavy Ion Research Facility in Lanzhou (HIRFL) to measure the β-delayed γ rays of 26P by silicon array and Clover-type high-purity Germanium (HPGe) detectors. Combining with results from the β decay of 26P and its mirror nucleus 26Na, the mirror asymmetry parameter δ ( ≡ft+/ft−− 1) was determined to be 46(13)% for the transition feeding the first excited state in the daughter nucleus. Our independent results support the conclusion that the large mirror asymmetry is close to the proton halo structure in 26P.
Image blur is very common in multispectral images, especially out-of-focus blur when the multispectral cameras are well focused on a specific channel. Therefore, it is important to recover the latent ...clear images from the blurred image. Many researchers have proposed a large number of methods for deblurring multispectral images. These algorithms assume that the relationship between channels is consistent. In fact, the relationship between different channels in multispectral images suffers from different blurring. Therefore it needs different processing for different channels. We propose a joint spatial and spectral filtering algorithm for multispectral images deblurring. We have introduced an adaptive Gaussian distribution as a constraint relationship between channels, which can effectively deblur the multispectral images. Extensive experiments show that our method achieves state-of-the-art results.
Expanded Edge Penalty Loss for Salient Object Detection Wang, Nan; Shi, Yuetian; Fang, Jie ...
2021 4th International Conference on Information Communication and Signal Processing (ICICSP),
2021-Sept.-24
Conference Proceeding
As an indispensable preprocessing technique for image understanding, salient object detection aims to extract interesting regions from an image for subsequent processing, which has attracted much ...attention since its wide range of applications. Recently, with the rapid development of artificial intelligence and machine learning, deep neural network especially deep convolutional neural network based methods have achieved competitive performances because of their strong feature representation capability. However, most of these methods often suffer from coarse boundaries. The main reason is that equal penalty factor is applied to each pixel in the image to optimize the network, but there are huge distinctions in prediction complexity among different ones actually. Specifically, pixels closer to the boundaries are increasingly difficult because of their huge gaps between structural information and semantic label. In these cases, we present an Expanded Edge Penalty Loss (E 2 PL) for salient object detection. E 2 PL gives bigger penalty factors to pixels distributed in boundary and near-boundary regions, and further dynamically adjusts their contributions to the model optimization. In addition, the experimental results on five public and challenging datasets have validated the superiority and effectiveness of the proposed method.
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