Optical and Quantum Electronics最新文献

A compact photonic method to generate frequency agile linearly frequency modulated (LFM) signals is proposed demonstrated by experiment and simulation. A Mach–Zehnder modulator driven by an LFM waveform train and an electrical controlled optical tunable delay line driven by a coding sequence is employed. According to time–frequency linear relationship of LFM signals, the initial frequency of the generated signals can be shifted by adjusting the introduced time delay. Experiments are carried out to verify the feasibility of the proposed generator. Frequency agile LFM signals under 2FSK and 4FSK modulation with symbol rate of 4 and 8 Msps are successfully obtained. 0.15 m range resolution and 4 Mbps communication data rate are achieved with a 1–1.5 GHz driving LFM signal. This scheme features compact structure and excellent tunability, which are promising to find applications in anti-jamming ISAC systems.

The fields of atomically thin two-dimensional transition metal dichalcogenides (2D TMDCs) have witnessed notable progress, resulting in a range of intriguing applications in nanoelectronics, photonics, sensing, energy storage, and opto-electronics. This article offers a comprehensive look at the latest progress in two-dimensional (2D) materials that go beyond graphene. Our main interest lies in TMDCs like MoS₂, WS₂, MoSe₂, and WSe₂. These materials are used in specific applications for advanced electronics and optoelectronics devices that depend on very thin atomic layers. Even though there have been challenges along the way in developing scalable and defect-free TMDCs on preferred substrates, scientists have managed to come up with innovative growth techniques that work well with both common and unconventional substrates. These developments have been driven by the increasing demand for precise and reliable TMDCs in real-world scenarios. TMDCs may play a critical role in the development in bio-medical applications, like biomedical imaging, medication administration, clinical diagnostics, and photodynamic therapy. A multilayer device architecture may facilitate the creation of a gate-defined quantum dot (QD) in transition metal dichalcogenides (TMDCs) for future quantum applications. Focus is on creating cutting-edge two-dimensional TMDCs with distinct features and new chemical characteristics. Furthermore, in addition to the realm of electronics, a considerable amount of research has focused on investigating the possibilities of these materials for energy and sensing applications, which are thoroughly analyzed.

We present a comprehensive performance analysis of injection-locked directly modulated laser (DML) for optical communication systems, focusing on both non-return-to-zero (NRZ) and 4-level pulse amplitude modulation (PAM4) signal transmission. We demonstrate real-time PAM4 40 Gbit/s transmission over 10 km of single-mode fiber enabled by optical injection locking without pre-emphasis or post-equalization, achieving a bit error rate (BER) below ({10^{-6}}), and doubling capacity compared to unlocked transmission with the same laser. Our study investigates the dependence of system performance on the injected power and frequency offset of the master laser. Results indicate that lower injection powers while maintaining a stable locking regime, yield better performance in terms of extinction ratio and BER. Optimized parameters lead to enhanced transmission performance, providing valuable insights into the design and optimization of injection-locked DML systems for optical communication applications employing direct modulation.

In this paper we investigate the behavior of localized solutions, specifically solitons, in a system of three coupled waveguides. The nonlinearity is modeled by a quasi-periodic modulation influencing the interaction between the waveguides. We analyze the evolution of the soliton profiles and their dynamics under varying modulation parameters, highlighting distinct behaviors such as attraction and repulsion among solitons. Our findings reveal that the system exhibits complex behaviors, depending on the interplay between the quasi-periodic modulation and the waveguide parameters. The study contributes to understanding the impact of quasi-periodic nonlinearity on soliton dynamics in coupled waveguide systems, laying the groundwork for potential applications in nonlinear optics and photonic devices.

In this paper, the effects of temperature, magnetic field, Rashba parameter, Mn atom impurity concentration and ellipsoid radius on the optical absorption coefficient of a dilute magnetic semiconductor ellipsoid quantum dot with spin–orbit Rashba interaction are investigated. Within the framework of the approximation of effective masses, the eigenvalue and the wave vector of the system are calculated. The obtained values are used to find the expression of the optical absorption coefficient for interband optical transitions. According to the results, temperature, magnetic field, Rashba parameter, Mn atom impurity concentration and ellipsoid radius change significantly affects the optical absorption coefficient.

Luminescence and energy-transfer in xDy₂O₃–ySm₂O₃–20SiO₂–20CaO–60P₂O₅ (x = 0.3, 0.5, 0.8; y = 0.5, 1.0, 1.5) glasses were investigated. The glass samples were synthetized by conventional melt quenching method. The combined luminescence of Dy³⁺ and Sm³⁺ ions in phosphosilicate glass was systematically measured. When excited by 361 nm, 373 nm, and 400 nm excitation light, Dy³⁺ and Sm³⁺ ions can emit light simultaneously. The glass sample 0.8Dy₂O₃–0.5Sm₂O₃–20SiO₂–20CaO–60P₂O₅ under 373 nm excitation presents a white light emission (the color coordinates are x = 0.3386, y = 0.3359) in the CIE diagram, and the correlated color temperature (CCT) is about 6000 K. The decay time test shows that there may be energy transfer from Dy to Sm. The Dy³⁺, Sm³⁺ codoped 20SiO₂–20CaO–60P₂O₅ glass will be further studied as a white light source in future.

Al_xIn_1−xP_ySb_zAs_1−y–z alloy is a novel pentanary zinc-blende semiconductor compound. The composition and temperature-dependent electronic band structure, refractive index (n), high-frequency dielectric constant ((varepsilon_{infty } ),) static dielectric constant ((varepsilon_{o} )) of nanostructured Al_xIn_1−xP_ySb_zAs_1−y–z lattice matched to InP substrate has been explored. Also, the relationship between the acoustic speed and phonon frequencies (ω_LO and ω_TO) of Al_xIn_1-xP_ySb_zAs_1−y–z for InP substrate with composition and temperature has been studied. Our calculations implemented a pseudopotential approach (EPM) with a virtual crystal approximation (VCA). The refractive index (n) and optical dielectric constant ((varepsilon_{infty } )) are decreased by increasing y from 0 to 0.5 and then increasing from y = 0.5 to 1. The static dielectric constant ((varepsilon_{o} )) is reduced by growing y from 0 to 0.4 and after that improved from y = 0.4 to 1. The ω_LO at (z = 0, T = 200 K) is increased by increasing the P content from 0 to about 0.28, and after that, it decreases by increasing y from 0.28 to 1. The ω_TO at (z = 0, T = 200 K) is increased when the phosphorus content is increased from 0 to 0.23 and decreases when the y value is increased from about 0.23 to 1. The n, and (varepsilon_{infty }) are enhanced by enhancing the temperature from 0 to 500 K, while the static dielectric constant is decreased by enhancing temperature. Our results and the available experimental and published data showed good agreement when compared. The flexibility of Al_xIn_1−xP_ySb_zAs_1−y–z originates from its ability to customize its electronic and optical properties by varying the composition. This makes it a potential material for many applications in optoelectronics such as solar cells, and high-speed electronics.

Perovskites are a class of materials with a diversified combination of various properties that allow them to be used in a wide range of technologies, from solar cells and LEDs to superconductivity and enormous magneto-resistance, as well as topological insulators. Perovskites, established as promising replacements for silicon in conventional solar cells, are employed in solid-state illumination, sensing, and energy harvesting, while others, like oxide perovskites, have dielectric solid properties. Phonons and electron–phonon interactions play a significant role in materials, especially in the hybridization between Sr-p, Al-s,p, Er-s,d, and Ce-d orbitals. This hybridization is essential for understanding the energy gap and refractive index, which are crucial for fabricating optoelectronic devices. Optical spectra reveal a prominent absorption peak between 4.0 and 12.0 eV, depending on the energy gap between the hybridized bands. The Boltztrap code calculates the thermoelectric characteristics of perovskite oxides in the temperature range of 0 to 800 K. We observed that parental and doped compounds have a higher merit ZT value (0.42) and (1.45), respectively. The Seebeck coefficients of both compounds fall into the positive range of 50–800 K, indicating that they are p-type materials, and after this range, their nature changed to n-type. It is observed that materials in the high reflectivity zone have strong thermoelectric capabilities and could be useful for solar heating. The band gap tuning affects their optoelectronic capabilities, which are essential for developing extremely efficient optoelectronic/luminescent devices.

The generating absorber design for the thermal heating system is contributed with the three-layer composition of a resonator layer using iron, the substrate part by Ferric oxide, and the design’s bottom layer in Titanium respectively. The exposed absorption rates depend on the overall range of wavelength and can be identified with the best wavelength numbers (µm) of 0.37, 0.61, 0.88, and 2.11. The overall bandwidth number that we can present for the current design is 2800 nm by the wavelength separation of 0.2 and 3 µm and shows an effective percentage of 93.34%. The other two bandwidth numbers over the 2800 nm are 1500 nm (95.1%) by a wavelength separation of 1.5 and 3 µm, and 1000 nm (97.54%) with a wavelength configuration of 1.5 and 2.5 µm. With the respective presentation of the current design, the used material types and parametric rates, the analysis exploration of the changed parametric values, and the conclusion of the proposed work will be presented properly. The generated solar absorber can be used in a variety of various industrial applications of food processing, mineral processing, water desalination, and chemical production.

The optical characteristics of far ultraviolet-C (FUV) laser diode (LD), with optimized position of AlN electron blocking layer (EBL), is shown to enhance carrier injection into the multiquantum well region. The carrier behavior mechanism of FUV LDs is illustrated through the simulation results. The optimization of AlN EBL position, in the p-region of the FUV LD, is studied in this work. FUV LD with p-AlN EBL, between last quantum barrier and p-waveguide, show an improved gain profile and stimulated emission. The optical power of this FUV LD has been found to have increased markedly. All our FUV LDs are emitting far ultraviolet-C emission i.e., 221 nm. To the best of our knowledge, 221 nm AlGaN LDs are hardly reported in the literature. Therefore, we believe our work on 221 nm AlGaN far ultraviolet-C laser diode will open new avenues for the research community.