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oe1(光电查) - 科学论文

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出版时间
  • 2019
  • 2018
  • 2017
  • 2016
研究主题
  • Optical pattern
  • Phase diagram
  • Surfactants
  • Optical properties
  • TB-MBJ
  • FP-LAPW
  • Electronic structure
  • GGA
  • DFT
  • Infrared Radiation
应用领域
  • Optoelectronic Information Science and Engineering
  • Chemistry
  • Materials Science and Engineering
机构单位
  • University of Texas at Arlington
  • Macquarie University
  • Universiti Malaysia Terengganu
  • Devi Ahilya University
  • National Institute of Information and Communications Technologies (NICT)
  • Povolzhskiy State University of Telecommunications and Informatics (PSUTI)
  • University of Sa?da Dr Tahar Moulay
  • University of Djillali Liabes
  • Assumption University
  • National Institute of Advanced Industrial Science and Technology
4497 条数据
?? 中文（中国） ▾

  • [IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Multi-Section Semiconductor Optical Amplifiers for Data Centre Networks

    摘要： The ever-growing Internet based services and applications, involving a huge amount of computing and storage resources, have been powered by data centres (DC) [1]. The storage and movement of data within the DCs is driving the requirement for cost-effective, higher capacity inter- and intra- next generation DC networks [2]. Within the context of these next generation DC networks, the ability to transmit very high data rates (100 – 400 Gb/s) over both short and long distances (intra or inter DC fibre links) is one of the main challenges (within the optical sector. The modulation format that is currently touted as the most suitable for such high capacities is 4-level pulse amplitude modulation (PAM4), which carries 2 bits per symbol. Optical amplification is needed for reach extension for inter- and intra- DC communications, Semiconductor optical amplifiers (SOAs) are needed to realize a low cost amplification solution. SOAs possess many advantages, including low power consumption, small footprint, wide bandwidth, being integrateable, and the ability to accommodate wavelength ranges beyond the scope of Erbium doped fibre amplifiers. However, the use of SOAs for linear amplification of C-band optical signals is still relatively limited, mainly due to the relatively large noise figure (NF) associated with them compared to erbium doped fiber amplifiers and low saturation powers of about 10 mW. Multi-section SOAs are known to possess superior NFs and larger saturation powers than an equivalent single-section SOA [3], and hence may provide performance benefit for reach extension for DC networks. In this work, we examine the use of a multi-section semiconductor optical amplifier (MS-SOA) [3] to provide an improvement in its use as a linear amplifier compared to a single section SOA. The MS-SOAs have been shown to have superior noise and linearity performance compared with single section SOAs. We configure the MS-SOA to operate in the low-NF mode with high saturation power mode and the equivalent single-section SOA. We compare the input power dynamic range for the MS-SOA and equivalent single-section SOA. We expect an improvement in the input power dynamic range of at least 3 dB [4]. The combination of a lower NF and higher saturation power enables crosstalk-free amplification of simultaneous multi-wavelength channels using the same SOA device.

    关键词： multi-section semiconductor optical amplifier,advanced modulation formats,data centre networks

    更新于2025-09-04 15:30:14

  • [IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Remote Sensing Using VNIR/SWIR Dispersive Imaging Spectrometers: Historical Development, Current State-of-the-Art, and Furture Trends

    摘要： The development of remote sensing using an imaging spectrometer is traced from its origins to the current highly performing spectral sensors. The advancement of the technology has primarily been driven by novel optical designs and focal plane array development. Current state-of-the-art dispersive sensors, employing innovative grating or prism arrangements, operate at low F-numbers while maintaining a high degree of aberration control. These challenging designs have been implemented in hardware with alignment tolerances on the order of microns. The application of imaging spectrometers to science problems that require highly accurate radiometry necessitates new characterization approaches that combine state-of-the-art radiometric sources and detailed sensor models. Future challenges are to reduce the size, weight, and power requirements while maintaining the performance of current systems.

    关键词： VNIR/SWIR,optical designs,remote sensing,imaging spectrometer,focal plane array

    更新于2025-09-04 15:30:14

  • [IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Registration of SAR and Optical Images by Weighted Sift Based on Phase Congruency

    摘要： In this paper, to address problems in the registration of synthetic aperture radar (SAR) and optical images due to large gray differences, the scale-invariant feature transform (SIFT) approach based on phase congruency (PC-SIFT) is proposed. This approach is used to address the gradient inversion in multi-source images, and it is based on optimizing the dominant direction interval of the descriptors. We construct a new descriptor by combining phase consistency and the gradient amplitude, which is referred to as PCG-SIFT descriptor. The proposed algorithm is suitable for multi-sensor images with large gray differences and significant edge features The results of experiments show that compared to the traditional gradient-based SIFT descriptor, the PC-SIFT descriptor and PCG-SIFT descriptor improve the robustness and matching probability of the registration algorithm for multi-source images.

    关键词： scale invariant feature transform,optical image,image registration,synthetic aperture radar

    更新于2025-09-04 15:30:14

  • Synthesis and Photophysical Characterization of Proton Transfer-Based Thiourea Derivatives: Potential Application as Colorimetric Naked-Eye Chemosensor for Fluoride Detection in Solution

    摘要： Two new thiourea derivatives were synthesized through the reaction of photoactive aminohydroxybenzazoles and p-isothiocyanate benzoic acid via nucleophilic addition reaction. The compounds were characterized using high resolution mass spectrometry with eletrospray ionization (HRMS-ESI), Fourier transform infrared (FTIR), 13C and 1H nuclear magnetic resonance (NMR) spectroscopies. UV-Vis and steady-state fluorescence in solution were also applied to characterize their photophysical behavior. The compounds present absorption in the ultraviolet region (ca. 300 nm) and fluorescence emission with a large Stokes’ shift in the UV-A and green region, with the longer wavelength related to phototautomerism in the excited state (ESIPT). Both compounds were investigated as optical sensors for the detection of anions in solution, presenting a potential application for fluoride ion detection by naked-eye and UV-Vis spectroscopy. The continuous variation method plot gave a 1:1 stoichiometric ratio between the chemosensors and F– for the new formed species. The UV-Vis and 1H NMR titration experiments reflect the establishment of a hydrogen bond interaction between the thiourea moiety of the chemosensors and fluoride. In addition, the presence of fluoride in solution tailored the fluorescence emission of one compound favoring the ESIPT emission.

    关键词： fluorescence,optical sensors,fluoride ion,ESIPT,benzazoles

    更新于2025-09-04 15:30:14

  • Choroidal Thickness at the Outside of Fovea in Diabetic Retinopathy Using Spectral-Domain Optical Coherence Tomography

    摘要： Purpose: To evaluate choroidal thickness at the outside of the fovea in patients with diabetic retinopathy using spectral-domain optical coherence tomography. Methods: We examined 87 eyes of 87 patients with diabetic retinopathy and 40 eyes of 40 normal patients. Patients with diabetic retinopathy were divided into 3 groups according to the grade of diabetic retinopathy and macular edema. The choroidal thickness was obtained at the fovea and outside of the fovea using enhanced depth imaging of Spectralis optical coherence tomography. One foveal and 8 peripheral images were selected and choroidal thickness was measured from the outer border of the retinal pigment epithelium to the inner scleral border. Results: Subfoveal choroidal thickness was thinner with increasing severity of diabetic retinopathy. However, there was no significant difference between groups without the nasal side of the fovea. A statistically significant difference was observed over the fovea at the superotemporal area. Conclusions: The choroidal thickness outside of the fovea was thinner with the severity of diabetic retinopathy and was more pronounced in the superotemporal area.

    关键词： Optical coherence tomography,Diabetic retinopathy,Choroidal thickness,Enhanced depth imaging

    更新于2025-09-04 15:30:14

  • A Case of Acute Bilateral Solar Retinopathy Diagnosed with Spectral Domain Optical Coherence Tomography

    摘要： To report a case of acute bilateral solar retinopathy diagnosed using spectral domain optical coherence tomography (SD-OCT). Case summary: A 74-year-old female patient consulted for amblyopia and metamorphopsia at a local hospital. On the patient’s first visit, there were no abnormal findings based on slit lamp microscope. Additional examinations were conducted since the patient complained of metamorphopsia with visual acuity and corrected vision. Fundus photography and SD-OCT examination showed symmetrical lesions near the bilateral macula. Several evaluations of the patient’s medical history confirmed that the patient was exposed directly to the sun for 30 minutes. One month after the first visit, visual acuity improved but metamorphopsia remained unchanged. Lesion status could not be confirmed by fundus photography. There was no abnormal finding on fluorescence angiography. SD-OCT examination still showed bilateral symmetric disruption of the outer retina but with no significant interval change. Conclusions: In the present case, the patient with bilateral intraocular lenses who complained of acute binocular amblyopia was diagnosed accurately through SD-OCT tests for bilateral symmetric disruption on the outer retina and repetitive evaluations of patient’s medical history.

    关键词： Spectral domain optical coherence tomography (SD-OCT),Acute bilateral solar retinopathy,Patient’s medical history,Disruption

    更新于2025-09-04 15:30:14

  • Hierarchical Metric Learning for Optical Remote Sensing Scene Categorization

    摘要： We address the problem of scene classification from optical remote sensing (RS) images based on the paradigm of hierarchical metric learning. Ideally, supervised metric learning strategies learn a projection from a set of training data points so as to minimize intraclass variance while maximizing the interclass separability to the class label space. However, standard metric learning techniques do not incorporate the class interaction information in learning the transformation matrix, which is often considered to be a bottleneck while dealing with fine-grained visual categories. As a remedy, we propose to organize the classes in a hierarchical fashion by exploring their visual similarities and subsequently learn separate distance metric transformations for the classes present at the nonleaf nodes of the tree. We employ an iterative maximum-margin clustering strategy to obtain the hierarchical organization of the classes. Experiment results obtained on the large-scale NWPU-RESISC45 and the popular UC-Merced data sets demonstrate the efficacy of the proposed hierarchical metric learning-based RS scene recognition strategy in comparison to the standard approaches.

    关键词： optical remote sensing (RS),Maximum margin clustering (MMC),metric learning

    更新于2025-09-04 15:30:14

  • [IEEE 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - Guangzhou, China (2018.10.8-2018.10.12)] 2018 IEEE SmartWorld, Ubiquitous Intelligence & Computing, Advanced & Trusted Computing, Scalable Computing & Communications, Cloud & Big Data Computing, Internet of People and Smart City Innovation (SmartWorld/SCALCOM/UIC/ATC/CBDCom/IOP/SCI) - Machine Vision-Based Segmentation and Classification Method for Intelligent Roller Surface Monitoring

    摘要： The surface quality of steel rollers is a key factor determining the quality of final products such as metal sheets and foils in the rolling industry. It is important to examine the surface quality of rollers since rollers with optical defects will always duplicate the defects onto the metal sheet or foil during rolling. The typical optical defects of rollers after finish grinding include speckles, chatter marks, swirl marks and combination of all of the above. They can hardly be modeled or shaped by the approach of micro topography or SEM (scanning electrical microscope). In this paper, an on-site machine vision system is firstly applied for stable inspection for the optical defects on roller surfaces. Then, an improved optical defect segmentation algorithm is developed based on the active contour model and the images including chatter marks and swirl marks. The normal surface state is classified by the combination of methods of Gabor filters, KPCA method and ELM neural networks. Finally, experiment are carried out to verify the efficiency of the improved segmentation method and the recognition rate of the combined classification algorithm.

    关键词： optical defect detection,big data,machine vision,roller surface monitoring

    更新于2025-09-04 15:30:14

  • Quantitative Evaluation of Broadband Photoacoustic Spectroscopy in the Infrared with an Optical Parametric Oscillator

    摘要： We evaluate the spectral resolution and the detection thresholds achievable for a photoacoustic spectroscopy (PAS) system in the broadband infrared wavelength region 3270 nm to 3530 nm driven by a continuous wave optical parametric oscillator (OPO) with P ≈ 1.26 W. The absorption spectra, IPAS(λi), for diluted propane, ethane and methane test gases at low concentrations (c ～ 100 ppm) were measured for ～1350 discrete wavelengths λi. The IPAS(λi) spectra were then compared to the high resolution cross section data, σFTIR, obtained by Fourier Transform Infrared Spectroscopy published in the HITRAN database. Deviations of 7.1(6)% for propane, 8.7(11)% for ethane and 15.0(14)% for methane with regard to the average uncertainty between IPAS(λi) and the expected reference values based on σFTIR were recorded. The characteristic absorption wavelengths λres can be resolved with an average resolution of δλres ～ 0.08 nm. Detection limits range between 7.1 ppb (ethane) to 13.6 ppb (methane). In an additional step, EUREQA, an artificial intelligence (AI) program, was successfully applied to deconvolute simulated PAS spectra of mixed gas samples at low limits of detection. The results justify a further development of PAS technology to support e.g., biomedical research.

    关键词： photoacoustic spectroscopy,optical-parametric oscillator,PAS,gas sampling,hydrocarbons,spectral deconvolution,EUREQA,OPO

    更新于2025-09-04 15:30:14

  • Distributed Fiber Optical Technology for Damage Identification of Engineering Structure

    摘要： To conduct optical fiber monitoring rock slide model test and optical fiber monitoring of steel concrete interface slip model test, the large tri-axial shear test of geotechnical engineering was used. First, the data of sliding distance and optical loss and their dynamic range were obtained. Second, the slide distance and fiber loss relation curve and the fitting equation were worked out. Finally, the typical applications of optical fiber sensing technology in Rock Engineering (high slope engineering, rock foundation of Dam Engineering) slope stability and geological disaster monitoring were put forward. The results showed that optical fiber sensing was very sensitive, and the loss value was 30 to 50dB. The dynamic range of rock slide monitoring fiber was 3 to 3.5mm, and the dynamic range of the interface slip monitoring fiber was 1.6mm. Thus, the sensing system can detect the sliding process of the interface between the concrete and the steel plate. It provides some reference for the sliding monitoring of the composite materials.

    关键词： Optical fiber sensing technology,engineering structure damage,sliding distance-fiber loss

    更新于2025-09-04 15:30:14