Frequency: Quarterly E- ISSN: 2277-6303 P- ISSN: Awaited Abstracted/ Indexed in: Ulrich's International Periodical Directory, Google Scholar, SCIRUS, EBSCO Information Services
"Inventi Impact: Optical Technologies" is the peer reviewed journal of Engineering & Technology. It has the research and review paper related to optical engineering and technologies, optical instruments and computational optics useful to engineers, researchers, physicists and mathematicians.
Optical wireless power transmission (OWPT) is a promising technology for remote energy supply, especially for powering Internet of things (IoT) terminals. Light-emitting diode (LED)-based power sources of OWPT are attractive for the development of high-performance systems without the constraints of safety issues. In this paper, the electricity output of a near-infrared LED-OWPT is significantly improved. The saturation output caused by the small lens aperture in the LED array collimation scheme was analyzed. The experiment achieved a maximum electricity output of more than 1 W from a 50 × 50 mm2 GaAs solar cell at 1 m transmission distance. In addition, the thermal features also proved the feasibility of a high-output LED-OWPT system for practical applications....
The BP/InSe heterojunction has attracted the attention of many fields in successful combined high hole mobility of black phosphorus (BP) and high electron mobility of indium selenide (InSe), and enhanced the environmental stability of BP. Nevertheless, photonics research on the BP/InSe heterostructure was insufficient, while both components are considered promising in the field. In this work, a two-dimensional (2D) BP/InSe heterostructure was fabricated using the liquidphase exfoliation method. Its linear and non-linear optical (NLO) absorption was characterized by ultraviolet−visible−infrared and Open-aperture Z-scan technology. On account of the revealed superior NLO properties, an SA based on 2D BP/InSe was prepared and embedded into an erbiumdoped fiber laser, traditional soliton pulses were observed at 1.5 μm with the pulse duration of 881 fs. Furthermore, harmonic mode locking of bound solitons and dark-bright soliton pairs were also obtained in the same laser cavity due to the cross-coupling effect. The stable mode-locked operation can be maintained for several days, which overcome the low air stability of BP. This contribution further proves the excellent optical properties of 2D BP/InSe heterostructure and provides new probability of developing nano-photonics devices for the applications of double pulses laser source and long-distance information transmission....
This paper presents an automatic optical equalizer based on a pair of in-house developed high efficiency, acousto-optic variable\r\noptical attenuators (AO-VOAs). The system is polarization insensitive and presents a wide bandwidth compatible with coarse\r\nwavelength division multiplexing (CWDM) requirements: 340 nm. The system operation is automatic and bidirectional and\r\nequalization is obtained in one single iteration of algorithm loop....
OFDM modulated millimeter wave (mm-wave) at 60GHz. In order to improve transmission of this system, the discrete Fourier\ntransform spread (DFT-Spread) technology and the averaging of the channel frequency response (H-averaging) technology are\napplied. The DFT-Spread technology helps to reduce the peak-to-average power ratio (PAPR) of the OFDM signal, and the Haveraging\ntechnology helps to optimize channel estimation.This is the first time that the two kinds of technologywere used together\nin this reverse modulation system. According to the simulation, the 22Gbit/s 16QAM-OFDM at 60GHz can be generated and\ntransmitted for 90km fiber transmission under the soft decision forward error correction (SD-FEC) threshold 3.8Ã?10-3.The results\nshow that the two jointed DSP algorithms can improve the reverse modulation system transmission performance obviously...
The structural modification of Ba0.5Sr0.5TiO3 (BST) nanocatalyst was successfully synthesized via sol-gel process. The BST\ncatalyst was modified by A-site (A-BST), A-B-site (A-B-BST), and B-site (B-BST) in order to investigate the effect of structurally\nmodified BST catalyst for photocatalytic decolorization of methylene blue. The structurally modified BST catalysts can increase\nthe non radiation energy such as phonon energy compared to that of BST one. The partial incorporation of the A-BST catalyst\nwas evidenced by the higher-ordered structure by increasing number of Ti4+ ions and the lattice oxygen. The A-B-BST and ABST\ncatalysts were given more electron-transfer in the TiO6 than that of BST and B-BST catalysts, respectively. The A-B-BST\ncatalyst promoted the oxidation of the lattice oxygen by holes capturing to form the chemisorbed oxygen, presenting the highest\nphotobleaching activity of methylene blue. On the other hand, more oxygen vacancies recombination of BST catalyst compared to\nthat of structurally modified BST catalysts presented the reduction of photocatalytic activity....
A monochromatic continuous millimeter-wave imaging system coupled with an infrared temperature sensor has been used to investigate artistic objects such as painting artworks or antiquities preserved at the museum of Aquitaine. Especially, 2D and 3D analyses have been performed in order to reveal the internal structure of a nearly 3500-year-old sealed Egyptian jar....
The phase-sensitive optical time-domain reflectometry (Φ-OTDR) system has shown substantial potential in distributed acoustic sensing applications. Accurate event classification is crucial for effective deployment of Φ-OTDR systems, and various methods have been proposed for event classification in Φ-OTDR systems. However, most existing methods typically rely on sufficient labeled signal data for model training, which poses a major bottleneck in applying these methods due to the expensive and laborious process of labeling extensive data. To address this limitation, we propose CLWTNet, a novel contrastive representation learning method enhanced with wavelet transform convolution for event classification in Φ-OTDR systems. CLWTNet learns robust and discriminative representations directly from unlabeled signal data by transforming time-domain signals into STFT images and employing contrastive learning to maximize inter-class separation while preserving intra-class similarity. Furthermore, CLWTNet incorporates wavelet transform convolution to enhance its capacity to capture intricate features of event signals. The experimental results demonstrate that CLWTNet achieves competitive performance with the supervised representation learning methods and superior performance to unsupervised representation learning methods, even when training with unlabeled signal data. These findings highlight the effectiveness of CLWTNet in extracting discriminative representations without relying on labeled data, thereby enhancing data efficiency and reducing the costs and effort involved in extensive data labeling in practical Φ-OTDR system applications....
Various applications require an antenna to provide coverage in the azimuthal plane while still retaining a\nlow profile. Transformation Optics method can be used to provide novel solutions to fulfill this objective. In this paper,\nthe design of dielectric superstrate inspired from Transformation Optics has been reported which completely reorients\nthe electromagnetic waves emanating from a directive antenna in the azimuthal plane. The physical space is modeled\nusing a virtual space composed of two opposed quarter circles. It is shown analytically that a dielectric-only solution\ncan be obtained from the transformation relations. Use of shift and compression factors has been applied to the\nmaterial parameter profile to achieve the reorientation. A full wave solution has been presented which reorients\nthe radiation pattern of a classical patch antenna in the azimuthal plane. The solution can be fabricated from isotropic\ndielectric materials....
Breakage and damage of fiber optic cable fibers seriously affects the normal operation of fiber optic networks, and it is important to quickly and accurately determine the type and location of faults when they occur. Unlike the old traditional methods, the advantages of wavelet transform in singular signal detection and signal filtering are used to analyze the Optical Time Domain Reflectometer curve signal and the fault detection method of fiber communication links with no relay and a large span in a high altitude area is given, which realizes the accurate detection and location of optical fiber communication link fault events under strong noise. The proposed technology detects fiber optic faults in high-altitude environments, with an average measurement accuracy improvement of 9.8%. The maximum distance for detecting fiber optic line faults is up to 250 km, which increases the system power budget. In the simulation experiment results, the infrastructure nodes of theWuhan FiberHome Laboratory successfully verified the superiority of this technology. The method has been directly applied to the on-site detection of ultra long optical fiber links in high-altitude areas, which has good financial significance and has certain reference significance for the future real-time detection of optical fiber cables....
This paper presents a method for gas concentration determination based on the measurement of the refractive index dispersion of a gas near the gas resonance in the near-infrared region (NIR). The gas refractive index dispersion line shape is reconstructed from the variation in the spectral interference fringesâ?? periods, which are generated by a low-finesse Fabry-Perot interferometer during the DFB diodeâ??s linear-over-time optical frequency sweep around the gas resonance frequency. The entire sensing system was modeled and then verified experimentally, for an example of a low concentration methane-air mixture. We demonstrate experimentally a refractive index dispersion measurement resolution of ..............
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