查看更多>>摘要：We aimed to examine the photon shielding characteristics of the TeO2-Bi2O3-B2O3 ternary glass system using EPICS2017 library and Phy-X/PSD software. Seven glass systems, TeBiB1-TeBiB7, with varying TeO2, Bi2O3, and B2O3 compositions were examined. The mass attenuation coefficient (MAC) evaluated with EPICS2017 (MAC(EPICS2017)) is slightly lower than MAC derived from Phy-X/PSD software (MAC(Phy-X/PSD)) by an average of 0.24%. MACEPICS2017 is in good agreement with MAC(Phy-X/PSD) at all the examined energies. Substituting an atom fraction of Bi2O3 with TeO2 and/or B2O3 resulted in the decrease of the total atomic cross-section of the glass, which in turn decreases the MAC. The linear attenuation coefficient (LAC) has comparatively higher values in the low energy zone (1.034-1.563 cm(-1) at 0.347 MeV), and the lowest values were reported at 2.506 MeV (in order of 0.2 cm(-1)). TeBiB1 has relatively higher LAC than TeBiB2-TeBiB7 glasses, whereas TeBiB6 and TeBiB7 glasses have nearly the same LAC and they possess lower LAC than the remaining glasses. The half-value layer (HVL) at 0.347 MeV takes the following values: 0.443 cm for TeBiB1, 0.532 cm for TeBiB2, 0.537 cm for TeBiB3, 0.541 cm for TeBiB4, 0.545 cm for TeBiB5, 0.670 cm for TeBiB6 and 0.670 cm for TeBiB7. The sequence of HVL is TeBiB6 > TeBiB7 > TeBiB2 > TeBiB3 > TeBiB4 > TeBiB5 > TeBiB1. The tenth value layer results revealed that the TeBiB1-TeBiB7 samples are good attenuators to the low energetic radiation. We found that TeBiB1 has the thinnest TVL (equals 4.439 cm, at 0.826 MeV), while TeBiB6 has the thickest TVL.
查看更多>>摘要：Advancement in the technology and optical communication sector has led to an increase in the demands of high bit rate and bandwidth, required for reliable data transmission. To meet such demands, future generation optical networks came into existence. In this paper, we propose a 100 Gbps, 4-channel WDM-MDM PON with two input wavelengths of 1550 nm and 1555 nm and using LP 01 and LP 11 modes. The system performance has been analyzed for different internal parameters considering return-to-zero (RZ), non-return-to-zero (NRZ), alternate mark inversion (AMI) and duobinary return-to-zero (DRZ) modulation schemes. DRZ modulation outperforms the other encoding schemes resulting in achievement of an acceptable bit error rate (BER) of <= 10(-14) over 10 km of fiber length at a 25 Gbps data rate.
查看更多>>摘要：This paper proposes a wavelength demultiplexer (WDM) in a metal-insulator-metal (MIM) waveguide based on square cascade resonators, which is numerically simulated using the finite difference time domain (FDTD) approach. WDM's basic construction is a plasmonic filter with two waveguides at the input and output (bass and drop) and a central cavity coupled horizontally to two square nanodisks. The proposed demultiplexer is formed by stacking three examples of these filters and square resonators with different dimensions and with a vertical cavity and a waveguide at the structure's input. The simulation results show that in the designed structure, the Full Width at Half-Maximum (FWHM) in some channels is around 10 nm. The proposed WDM has a cross talk effect of less than 25 dB. In fact, when compared to structures at its level, this structure has a high sensitivity, a low cross talk effect, and a proper Figure of Merit (FoM). If the geometric parameters and insulation's refractive index (RI) are set appropriately, the transmission qualities are able to tune to desired level. The proposed structure has the potential to be utilised in optically integrated circuits, nanosensors, to develop into a 1 x N demultiplexer, and ultracompact plasmonic devices.
查看更多>>摘要：This paper introduces vanadium pentoxide films that were grown under the different laser pulse energy (440,640 and 840) mJ/pulse deposition conditions in order to observe the impact on the structural, optical, morphology, and electric properties and to specify the optimum condition. V2O5 nanospheres (V(2)O(5)NSs) are synthesized on porous silicon n-type Si (100) by pulsed laser deposition (PLD) method at room temperature. Q-switching Nd: YAG laser 1064 nm and the pulse duration of 10 ns and a repetition rate of 1 Hz use in the ablation process. X-ray diffraction (XRD), photoluminescence (PL), Raman spectroscopy, and field emission-scanning electron microscope (FE-SEM) were used to undertake structural and optical analysis. The findings the indicated that as-deposited films crystallized well in 840 mJ, in comparison to other forms of laser pulse energy. Photoluminescence spectra reveal intense and broad green light emission with a high intensity at around 545 nm. The PL intensity with an energy gap of the V(2)O(5)NSs (2.26, 2.27, and 2.28) eV with different laser pulse energies (440,640 and 840) mJ/pulse, respectively has been noted. Electrical properties determined from the current-voltage characteristics and Photocurrent density - voltage of Al/V(2)O(5)NPs/PS/n-Si/Al. The results showed that detectivity improves as laser pulse energy increases, 80% quantum efficiency was achieved in 840 mJ/pulse laser ablated energy. The results indicate that V(2)O(5)NSs are a promising candidate for high-performance photodetector applications in optoelectronics.
查看更多>>摘要：In order to realize the automatic quality measurement of laser welding parts, an automatic on-line quality measurement system is established. The optical coherence tomography algorithm used in the system is studied. Firstly, the test equipment of laser welding quality inspection system is built based on optical coherence tomography algorithm. Then, the typical control algorithm is analyzed by taking the scanning galvanometer control as an example, that is, high-precision scanning and high-precision image acquisition in X and Y directions are realized. Then, the image is processed by dual-tree complex wavelet transform. Finally, the test sample is tested with the test equipment and the test results are analyzed. Experimental results show that this method can detect the quality of laser welding seam, and the detection accuracy is 5 mu m. It provides industrial solutions for the online inspection of the laser welding to enable consistent and high quality welds.
查看更多>>摘要：The spatial positions of multiple fragments formed by projectile explosion have random uncertainty dispersion state, so it is difficult to recognize each fragment and measure its spatial position when multiple fragments reach a certain area at the same time. In order to solve the problem, we propose a test method for measuring the spatial positions of multiple fragments based on dual light field intersection imaging mechanism, study refocusing principle of micro-lens array and four-dimensional light field imaging information, and establish the analytical model of spatial positions of multiple fragments. We set up the uncertainty error evaluation function of two light field cameras intersection test method from the perspective of engineering design, and give the uncertainty analysis method under engineering model. The influence of various factors on the uncertainty of test results under the engineering model is analyzed by calculation. Combined with the actual test data of the wooden target, the results show that the fragment spatial position test method based on dual light field intersection imaging mechanism is feasible and scientific.
查看更多>>摘要：In this work, a dual polarization-quadrature phase shift keying (DP-QPSK) modulation scheme has been used for analysing the performance of terrestrial MDM-WDM FSO link at a data rate of 1000 Gbps. The proposed link has been investigated considering linearly polarized (LP) 01 and 02 modes with a channel capacity and spacing of 10 x 100 Gpbs and 10 GHz respectively. The performance of the system has been evaluated in terms of received optical power and signal to noise ratio (SNR) for clear weather, light, medium and heavy fog conditions over a propagation range varying from 1.2 km to 20 km.
Al-Hadeethi, YasSayyed, M., IRaffah, Bahaaudin M.Kumar, Ashok...
8页
查看更多>>摘要：The conventional melt quenching procedure has been adopted for the fabrication for the PbO B2O3 - CuO - CaO glass system. The effect of the addition of the PbO on the mechanical and gamma ray shielding properties of dark black CuO - CaO - B2O3 glasses has been investigated. The sample's density increases from 3.937 g/cm3 to 4.762 g/cm(3) when the PbO concentration goes from 35 to 50 mol percent. The mechanical characteristics based on the coordination numbers of the cations present in the sample indicates that the elastic moduli decrease with the addition of the PbO. The radiation shielding parameters for the novel glasses were reported using Phy-X/PSD for the radiation energies between 0.015 and 15 MeV. The linear attenuation coefficient (LAC) with different concentrations of PbO decreases with the increase in the energy up to 0.1 MeV with a sudden increase in the LAC happening at this energy. A very quick decrease in the LAC is noticed when the energy reaches 0.03 MeV. The glass with composition of 50PbO-20B2O3- 15CuO-15CaO shows the maximum values for LAC. We compared the mass attenuation coefficient (MAC) for our prepared A1-A4 glasses with other glass systems at 0.662 MeV. We found that the samples with a composition of 35PbO-35B2O3-15CuO-15CaO shows a comparable MAC with 45B(2)O(3)-20Bi(2)O(3)-15Sb(2)O(3)-20Na2O2. The effective atomic number (Z(eff)) at 0.1 MeV is very high due to the K-edge of Pb. The Zeff results demonstrated that when the PbO increases on the expense of B2O3, the Zeff is improved.
Ansari, Muhammad BasitChandio, Ali DadRizvi, Syed Bilal HasanMadad, Shabbir...
8页
查看更多>>摘要：Fabrication of anti-reflective and hydrophobic glass surfaces has been an active area of research. It has been reported that most of the coatings developing methods produces fragile and thin coatings which consequently have limited practical usage because of their abrasion-sensitivity. However, with thicker coatings, transparency of glass gets compromised, rendering it inoperable to be used in applications requiring transparency. To overcome the problem there is a need to have a solution that can practically produce glass substrates having hydrophobic properties without significant loss in transmittance, making them useful in anti-reflective hydrophobic applications. The presented work focuses on utilizing the effects of surface roughness and surface chemistry on commercial grade glass substrates to produce robust hydrophobic surfaces without appreciable compromise on transmittance. Metal Assisted Chemical Etching (MACE) was used to develop controlled structured surface roughness on the glass substrate whereas the surface chemistry was modified via silane treatment. The results demonstrated surface roughness and surface chemistry are both equivalently important to achieve an optimum surface having hydrophobic properties without any major transmittance lost. Successful implementation of the silver (Ag) particle assisted MACE process and chemistry modification of the glass surface resulted in contact angles above 100 degrees with nearly 2-3% transmission lost in reference to the transmittance of parent glass substrates.
Sayyed, M. I.Prabhu, Nimitha S.Jecong, J. F. M.Kamath, Sudha D....
9页
查看更多>>摘要：The mechanical and gamma radiation shielding properties of the B2O3-TeO2-Al2O3-ZnO-MgO-Li2O glass system were investigated. In the glass matrix, TeO2 was substituted for B2O3 in amounts ranging from 10 to 60 mol%. The glasses had Young's modulus of 45-87 GPa, a bulk modulus of 32-77 GPa, a shear modulus of 18-33 GPa, and a longitudinal modulus of 56-121 GPa. The role of TeO2 in transforming bridging oxygens into non-bridging oxygens was established by the decreasing elastic moduli and increasing molar volume with successive TeO2 additions. EpiXs software was used to investigate the changes in the mass attenuation coefficient (MAC) with varying photon energy and TeO2 content. The ratio of the mean free path (MFP) of the glasses with the lowest and highest TeO2 contents at various energies was investigated. The glass with the highest content of TeO2 had the smallest half-value layer (HVL) and tenth value layer (TVL), making it the best attenuator of all samples evaluated. The radiation shielding parameters of the titled glass system were compared to those of various similar glass systems, and the results indicated that the titled glass system may be used in radiation shielding.
NSTL
Elsevier