Optical and Quantum Electronics最新文献

This paper presents a novel, compact, and a dual-port MIMO antenna designed for ultrawideband, Sub-6 GHz, Industrial, Scientific, and Medical (ISM) band, and Internet of Things (IoT) applications. The antenna uses a stretchable jeans textile substrate embedded with elastomeric materials, enhancing its dielectric properties and flexibility. The innovation in this design stems from the introduction of defects (slots) on the stubs connected to a partially etched ground plane, which significantly improves isolation, achieving a port isolation of 47.5 dB which is superior to conventional designs. Operating across a wide frequency range of 2.82–14.23 GHz, it supports critical bands including WLAN, WiMAX, RAS, N79, C-band, and Sub-6 GHz, making it ideal for next-generation wireless systems. The antenna, with its compact footprint of 50 × 35 mm², also covers ISM applications (2.4 GHz/5.8 GHz), making it versatile for medical and industrial communication needs. It delivers excellent performance, including a return loss (S₁₁) below −10 dB, diversity gain above 9.95, and channel capacity loss below 0.25 bits/s/Hz. Additionally, it maintains a mean effective gain below 0.16 dB, an envelope correlation coefficient under 0.054, and a peak gain of 3.97 dB with over 82.45% radiation efficiency. These features make the proposed antenna a significant advancement, suited for future communication systems, wearable devices, and IoT-based Sub-6 GHz and ISM band applications.

In this research, and photoelectric properties of two possible allotropes β₁₂-borophene and δ₆-borophene have been investigated using first-principles calculations for 1–4 borophene layers. The band structures, charge density, partial density of states, electrostatic potential and absorption spectra are calculated for multilayer borophene. The obtained results indicate that all layers exhibit anisotropic metallic behavior due to the interlayer charge transfer in β₁₂-borophene and δ₆-borophene. Furthermore, band splitting was increased with layer number, which was more pronounced in β₁₂-borophene. This finding was verified by the partial density of states. Moreover, the anisotropic structure of β₁₂-borophene and δ₆-borophene is evident in the calculated absorbance, which, while relatively low, distinctly exhibits a dependence on the number of layers. Meanwhile, multilayer borophene was almost transparent in visible region with weak absorption, which reflected its anisotropic structure. Density functional theory results suggested that multilayer borophene provided a critical basis for future research on photonic technology. These findings highlighted the substantial potential of multilayer borophene for photonic technology.

Miniaturized and integrated polarization conversion devices have high potential application value, and switching devices that integrate absorption and polarization conversion are receiving increasing attention. However, most of these devices are reflective polarization conversion devices, and reflective devices have many inconveniences. Therefore, in this paper, we design bifunctional metamaterial devices that can be switched between transmission polarization conversion and absorption functions, which are composed of vanadium dioxide (VO₂), polyimide, and gold. When VO₂ is in the insulating state, the structure has a transmission polarization conversion function to realize the linear polarization conversion function. The polarization conversion rate exceeds 99.9% in the 0.2–1.4 THz range. The polarization conversion is explained by analyzing the distribution of surface currents and electric fields. When VO₂ is in the metallic state, the structure has a multi-band absorption function. The peak absorption reaches 99.4% at 1.536 THz. The main reason for the strong absorption effect is explained by analyzing the distributions of surface currents, electric and magnetic fields in combination with the impedance matching theory. The device is tunable and multifunctional, and can be used in terahertz imaging, active switching and other fields.

This study introduces a novel design of an optical waveguide for enhancing supercontinuum (SC) generation spectra in mid-infrared region. This research contains two types of tellurium-based chalcogenide waveguides. The core and cladding materials are composed of Ge₂₀As₂₀Se₁₅Te₄₅ and Ge_11.5As₂₄S_64.5 respectively. By employing the hyperbolic secant laser pulses with 50 femtosecond full-width half-maxima (FWHM), the structure results broad SC. The type-C waveguide produces SC ranging from 3 to 7.2 µm, 2.8 to 8.7 µm and 2.7 to 10.5 µm while pumped by lasers with a central wavelength of 4.5µm and produces 3.5 to 8µm, 3.1 to 9.2 µm and 2.8 to 11.1 µm, with central wavelength 5.1 µm and pulse peak powers of 0.5 kW, 1 kW and 2 kW, respectively. These findings highlight the potential of these waveguides in producing broad spectra within SC sources, showcasing their utility in advanced light generation applications.

Soliton dynamics in water waves are crucial for understanding and mitigating their impacts in coastal engineering, oceanography, and climate studies. This research investigates the soliton solutions of the Camassa–Holm nonlinear Schrödinger equation, a model suitable for studying the interaction between shallow and deep water waves. By applying a traveling wave transformation and the extended sinh-Gordon equation expansion method, the novel exact wave solutions are derived. These solutions, expressed in trigonometric and hyperbolic functions, reveal a variety of patterns, including dark solitons, bright singular solitons, two-bright singular solitons, periodic anti-peakons, V-shaped, and W-shaped periodic waves. The dominance of the Camassa–Holm equation component is evident in the peakon solutions, while the dark and bright solitons highlight the influence of the nonlinear Schrödinger equation component. Furthermore, the attained solutions are compared with existing results obtained using alternative techniques for this model.

In this paper, we present a graphene-based band-pass filter featuring rectangular-shaped resonators, based on research into the sensing characteristics of surface plasmon polaritons (SPP). The finite-difference time-domain (FDTD) method and simulations reveal that the transmission spectrum of this structure exhibits a dual-mode spectrum. This structure operates at two functional modes with wavelengths of 1135 nm and 1705 nm, and its compact size measures 330 nm × 480 nm. We investigated the effect of geometric parameters on the pass bands, finding transmission rates as high as 0.97 and 0.88, sensitivities of 2166.6 nm/RIU and 2000 nm/RIU, and figures of merit (FOM) of 50.38 and 38.46 RIU⁻¹. Due to the minimal difference in the RI of cancer cells and the high sensitivity of the sensor, it is highly effective for cancer cell detection. Additionally, the accuracy of the sensor's performance is validated using a one-sample T-test, which confirms the precision and reliability of the designed sensor.

In dispersion oscillating fiber, various optical wave patterns attained for inhomogeneous NLS equation with parabolic tapered profile. With the presence of tapered function, variable coefficient nonlinear Schrödinger equation is considered. Especially, parabolic tapered profile is adopted to tapered function. Numerous optical soliton wave patterns attained for periodically oscillating dispersion profiles. The group of nonlinear optical wave patterns obtained in the present work are useful for control and management of optical waves in nonlinear tapered fiber medium. Moreover, these results are might be helpful in understanding of optical solitons in dispersion oscillating fiber more deeply.

Sulphamic acid yielded bulk single crystals (pure and Cs doped SA) through a conventional growth process at 30°C. Doping with Cs: SA significantly impacted the material’s structure, as evidenced by stronger XRD peaks indicating enhanced crystallinity and FT-IR spectra showing characteristic peak broadening and intensity variations that confirm dopant incorporation into the SA lattice. From the EDAX analysis the presence of Cs ions in the SA lattice. The effect of Cs: SA doping on the optical properties of the crystals was investigated by calculating their absorbance and band gap. The grown crystal’s Meyer’s index value indicates that it belongs to the soft material group. Dielectric investigations were carried out to comprehend the diverse polarisation mechanisms at various temperatures. It is clear from the thermal investigation that the crystal dissociates. Doping Cs: SA crystals significantly increased their third-order susceptibility, indicating enhanced nonlinear optical (NLO) properties.

Ni and Mg-doped ZnO nanoparticles have been synthesized using a facile sol–gel route. The XRD pattern revealed that the prepared samples have a wurtzite structure. The size of the particles is measured in the range of 13–17 nm, where the maximum size reduction is received for the Mg at. 2%—doped sample and discussed in terms of induced lattice distortion. The blue band absorption at 356 nm exists only in Mg-doped Zn_0.96Ni_0.04O. The optical band gap is wide-ranging between 3.91 and 3.87 eV, with Mg = 2% -doped Ni:ZnO nanoparticles exhibiting a red shift due to defect concentrations. The FTIR spectra confirmed the existence of Ni and Mg in ZnO structures as well as the presence of molecular vibrations. The PL spectra exposed emissions in UV, blue, and green regions, and changes in their intensities were related to zinc vacancy and oxygen defect sites. The PL spectra exposed emissions in UV, blue, and green regions, and changes in their intensities were related to zinc vacancy and oxygen defect sites.

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