In the present paper we summarize the methods and results of calculations for the theoretical informational quantities obtained in our works for the nondispersive optical fiber channel. We considered two models: the per-sample model and the model where the input signal depends on time. For these models we found the approach for the calculation of the mutual information exactly in the nonlinearity parameter but for the large signal-to-noise power ratio. Using this approach for the per-sample model we found the lower bound of the channel capacity in the intermediate power range.
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http://dx.doi.org/10.3390/e22060607 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Center for Optics Research and Engineering, State Key Laboratory of Crystal Materials, Shandong University, Qingdao 266237, China.
Shear mode ultrasonic waves are in high demand for structural health monitoring (SHM) applications owing to their nondispersive characteristics, singular mode, and minimal energy loss, especially in harsh environments. However, the generation and detection of a pure shear wave using conventional piezoelectric materials present substantial challenges because of their complex piezoelectric response, involving multiple modes. Herein, we introduce a high-quality piezoelectric crystal BiSiO (BSO), exhibiting a robust piezoelectric response ( = 45.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Mechanical Engineering, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
The intrinsic temperature dependence of Raman-active modes in carbon nanotubes (CNTs), particularly the radial breathing mode (RBM), has been a topic of a long-standing controversy. In this study, we prepared suspended individual CNTs to investigate how their Raman spectra depend on temperature and to understand the effects of environmental conditions on this dependency. We analyzed the intrinsic temperature dependence of the main Raman-active modes, including the RBM, the moiré-activated R feature, and the G-band in double-walled carbon nanotubes (DWCNT) and single-walled carbon nanotubes (SWCNTs) after complete desorption of air.
View Article and Find Full Text PDFNanophotonics
February 2024
Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China.
Cylindrical vector beams (CVBs) hold considerable promise as high-capacity information carriers for multiplexing holography due to their mode orthogonality. In CVB holography, phase holograms are encoded onto the wave-front of CVBs with different mode orders while preserving their independence during reconstruction. However, a major challenge lies in the limited ability to manipulate the spatial phase and polarization distribution of CVBs independently.
View Article and Find Full Text PDFIn this paper, a novel thermo-optic metagrating based on phase-change material (vanadium dioxide, VO) is proposed for broadband, polarization-independent, and non-dispersive transmission modulation at the telecommunication wavelengths. In the pursuit of concurrent attainment of multiple performance objectives, nanostructured VO metagratings are optimized numerically using inverse design algorithms. Notably, adjoint optimization pertaining to both phases of VO facilitates better modulation capabilities within free-form shaped VO metagratings compared to shape-optimized methods with predetermined designs.
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