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wavelength division multiplexing passive optical network modelling using optical system simulator
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Due to the continuing demand for larger bandwidth, the optical transport becoming general in the access network. Using optical fiber technologies, the communications infrastructure becomes powerful, providing very high speeds to transfer a high capacity of data. Existing telecommunications infrastructures is currently widely used Passive Optical Network that apply Wavelength Division Multiplexing (WDM) and is awaited to play an important role in the future Internet supporting a large diversity of services and next generation networks. This paper presents a design of WDM-PON network, the simulation and analysis of transmission parameters in the Optisystem 7.0 environment for bidirectional traffic. The simulation shows the behavior of optical fiber links when the signal passes through all the components such as optical fiber, splitters, multiplexers then find a good quality of signal in all receivers. The system performance is presented through various parameters such as BER analyzer and the Eye Diagram.

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Publication Date
Sat Jun 27 2020
Journal Name
Iraqi Journal Of Science
Influence of Laser Energy and Annealing on Structural and Optical Properties of CdS Films Prepared by Laser Induced Plasma
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The current study was achieved on the effects of laser energy and annealing temperature on x-ray structural and optical properties, such as the UV-Visible spectra of cadmium sulfide (CdS). The films were prepared using pules laser deposition technique (PLD) under vacuum at a pressure of 2.5×10-2 mbar with different laser energies (500-800 mJ) and annealing at a temperature of 473K. X-ray diffraction patterns and intensity curves for the CdS showed that the formation of CdS multi-crystallization films at all laser energies. The optical properties of the films were studied and the variables affecting them were investigated in relation to laser energy and changes in temperature.

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Publication Date
Mon Jun 01 2020
Journal Name
Iraqi Journal Of Physics
Influence of Sn doping ratio on the structural and optical properties of CdO films prepared by laser induced plasma
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In this work, we study the effect of doping Sn on the structural and optical properties of pure cadmium oxide films at different concentrations of Tin (Sn) (X=0.1,0.3 and 0.5) .The films prepared by using the laser-induced plasma at wavelength of laser 1064 nm and duration 9 ns under pressure reached to 2.5×10-2 mbar. The results of X-ray diffraction tests showed that the all prepared films  are polycrystalline. As for the topography of the films surface, it was measured using AFM , where the results showed that the grain size increases with an increase in the percentage of doping  in addition to an increase in the average roughness. The optical properties of all films have also been studied through the absorbance s

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Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Science
The Effect of Au Nanoparticles on the Structural and Optical Properties of (NiO:WO3) Thin Films Prepared by PLD Technique
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      In the present investigation, (NiO:WO3 ) thin films were deposited at RT onto glass substrates  using PLD technique employing focused Nd:YAG laser beam at 600 mJ with a frequency second radiation at 1064 nm (pulse width 9 ns) repetition frequency (6 Hz), for 400 laser pulses incident on the target surface .The structural, morphological and optical properties of the films doped with  different concentration of  Au content (0.03, 0.05, and 0.07) were examined with X-ray diffractometer(XRD), Atomic Force Microscope(AFM) , UV–Vis spectrophotometer . The results show that the films were amorphous with small peaks appearing when doped with AuNPs . The XRD peaks of the deposited NiO:WO3 were enhanced with increasing t

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Publication Date
Sat Apr 30 2022
Journal Name
Iraqi Journal Of Science
Effect of Films Thickness on Structural and Optical Properties of Gold (Au) Thin Films Prepared by DC Magnetron Sputtering
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In this paper, the effect of films thickness on the structural and optical properties of gold (Au) thin films prepared by the DC sputtering method was studied. At three different deposition times, three samples of gold thin films of three different thicknesses (200,400, and 600 nm) were prepared. X-ray diffraction patterns, scanning electron microscopy (SEM), and atomic force microscopy (AFM) images, as well as optical spectroscopy, were used to characterize thin films. The crystalline structure of gold thin films was determined by the XRD pattern which showed to be cubic phase and polycrystalline in nature. The preferred orientation was (111) at 2Ѳ equal 37.4. The effect of deposition time on the morphology of the deposited films was v

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Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Engineering
Mobile position estimation using artificial neural network in CDMA cellular systems
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Using the Neural network as a type of associative memory will be introduced in this paper through the problem of mobile position estimation where mobile estimate its location depending on the signal strength reach to it from several around base stations where the neural network can be implemented inside the mobile. Traditional methods of time of arrival (TOA) and received signal strength (RSS) are used and compared with two analytical methods, optimal positioning method and average positioning method. The data that are used for training are ideal since they can be obtained based on geometry of CDMA cell topology. The test of the two methods TOA and RSS take many cases through a nonlinear path that MS can move through that region. The result

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Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Engineering
Mobile Position Estimation using Artificial Neural Network in CDMA Cellular Systems
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Using the Neural network as a type of associative memory will be introduced in this paper through the problem of mobile position estimation where mobile estimate its location depending on the signal strength reach to it from several around base stations where the neural network can be implemented inside the mobile. Traditional methods of time of arrival (TOA) and received signal strength (RSS) are used and compared with two analytical methods, optimal positioning method and average positioning method. The data that are used for training are ideal since they can be obtained based on geometry of CDMA cell topology. The test of the two methods TOA and RSS take many cases through a nonlinear path that MS can move through tha

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Publication Date
Thu Dec 15 2011
Journal Name
Iraqi Journal Of Laser
Different Wavelength Femtosecond Laser Pulses Generated by Diode Pumped Ti: Sapphire Crystal
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The relation between the output power and wavelengths for a 532nm 3W frequency doubled diode pumped solid state laser pumped Ti:Sapphire crystal is investigated. A 20 femtosecond pulse at 800 nm is obtained. A 320 mW is found to be the highest power at 800nm. Below this wavelength value and above the power was found to deviate from highest output value.

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Publication Date
Fri Jun 24 2022
Journal Name
Iraqi Journal Of Science
The Electron Temperature and The Electron Density measurement by Optical Emission Spectroscopy in Laser Produced Aluminum Plasma in Air
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In this work the Aluminum plasma in Air produced by Nd: YAG pulsed laser, (λ = 1064 nm, τ = 6 ns) has been studied with a repletion rate of 10 Hz. The laser interaction in Al target (99.99%) under air atmosphere generates plasma, which is produced at room temperature; with variation in the energy laser from 600-900 mJ. The electron temperature and the electron density have been determined by optical emission spectroscopy and by assuming a local thermodynamic equilibrium (LTE) of the emitting species. Finally the electron temperature was calculated by the Boltzmann plot from the relative intensities of spectral lines and electron density was calculated by the Stark-broadening of emission line.

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Publication Date
Tue Feb 01 2022
Journal Name
Webology
Efficient Eye Recognition for Secure Systems using Convolutional Neural Network
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Publication Date
Wed Nov 02 2016
Journal Name
Australian Journal Of Basic And Applied Sciences
Full synchronization of 2$\times$ 2 optocouplers network using LEDs
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The synchronization of a complex network with optoelectronic feedback has been introduced theoretically, with use of 2×2 oscillators network; each oscillator considered is an optocoupler (LED coupled with photo-detector). Fixing the bias current (δ) and increasing the feedback strength (Ԑ) of each oscillator, the dynamical sequence like chaotic and periodic mixed mode oscillations has been observed. Synchronization of unidirectionally coupled of light emitting diodes network has been featured when coupling strength equal to 1.7×10-4. The transition between non-synchronization and synchronization states by means of the spatio-temporal distribution has been investigated.