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External Switching Dynamics of Optical Bistability System Simulation
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In this work, the external switching dynamics of a Fabry-Perot etalon are studied via optical bistability system simulation. The simulated set-up of this investigation consists of two laser beams; the first beam is continuous (CW) which is considered as a biasing beam and capable of holding the bistable system for a certain range, which we are interested in, from a point that is very close self-switching to a point where the switching is unachievable. The second beam is modulated by passing the first beam through an acousto-optic modulator (AOM) to produce pulses with a minimum rise time and is used as an external source (coherent switching). In this work, we obtained the optical bistable loops by applying absorption coefficient (α) = 20cm-1, e sample etalon thickness (D) = 110μm, forward mirror reflectivity (Rf) = 0.6, and backward mirror reflectivity (Rb) = 0.95. The steady state characteristic of an initial detuning of the cavity (φ0) = 0.8 was studied at the conditions of no external input pulse intensity (M(t) = 0) and switching that takes place at Is(ON)= 0.57mW and Is(OFF) = 0.4mW.

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Publication Date
Wed Apr 12 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
the Optical Properties of Electrostatic Design and Study Mirror By using Bimurzaev Technique
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In this research a computational simulation  has been carried out on the design and properties of the electrostatic mirror and a mathematical expression has been suggested  to represent the axial potential of an electrostatic mirror. The electron beam path using the Bimurzaev  technique had been investigated as mirror trajectory with the aid of Runge – Kutta  method. The spherical and chromatic aberration coefficients of mirror has computed and normalized in terms of the focal length. The choice of the mirror depends on the operational requirements. The Electrode shape of mirror two electrodes has been determined by using package SIMION computer program. Computations have shown that the suggested potentials giv

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Publication Date
Fri Nov 29 2019
Journal Name
Iraqi Journal Of Physics
Morphological and optical properties of V2O5:TiO2 thin film prepared by PLD technique
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              In this work, pure and doped Vanadium Pentoxide (V2O5) thin films with different concentration of TiO2 (0, 0.1, 0.3, 0.5) wt  were obtained using Pulse laser deposition technique on amorphous glass substrate with thickness of (250)nm. The morphological, UV-Visible and Fourier Transform Infrared Spectroscopy (FT-IR) were studied. TiO2 doping into V2O5 matrix revealed an interesting morphological change from an array of high density pure V2O5 nanorods (~140 nm) to granular structure in TiO2-doped V2O5 thin film .Transform Infrared Spectro

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Publication Date
Sun Feb 03 2019
Journal Name
Iraqi Journal Of Physics
Synthesis and study the optical properties of Ge20 Bix Se80-x thin films
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Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Theoretical Studies of Sum Optical Properties for InAs (001) by Surface Differential Reflectivity
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The real and imaginary part of complex dielectric constant for InAs(001) by adsorption of oxsagen atoms has been calculated, using numerical analysis method (non-linear least square fitting). As a result a mathematical model built-up and the final result show a fairly good agreement with other genuine published works.

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Calculations of Signal to Noise Ratio (SNR) for Free Space Optical Communication Systems
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In this paper, we calculate and measure the SNR theoretically and experimental for digital full duplex optical communication systems for different ranges in free space, the system consists of transmitter and receiver in each side. The semiconductor laser (pointer) was used as a carrier wave in free space with the specification is 5mW power and 650nm wavelength. The type of optical detector was used a PIN with area 1mm2 and responsively 0.4A/W for this wavelength. The results show a high quality optical communication system for different range from (300-1300)m with different bit rat (60-140)kbit/sec is achieved with best values of the signal to noise ratio (SNR).

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Publication Date
Tue May 01 2012
Journal Name
Iraqi Journal Of Physics
Structural and optical properties of BaTiO3 thin films prepared by pulsed laser deposition
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BaTiO3 thin films have been deposited on Si (111) and glass substrates by using pulsed laser deposition technique. The films were characterized by using X-ray diffraction, atomic force microscope and optical transmission spectra. The films growth on Si after annealing at 873K showed a polycrystalline nature, and exhibited tetragonal structure, while on glass substrate no growth was noticed at that temperature. UV-VIS transmittance measurements showed that the films are highly transparent in the visible wavelength region and near-infrared region for sample annealing on glass substrate. The optical gap of the film were calculated from the curve of absorption coefficient (αhν) 2 vs. hν and was found tobe 3.6 eV at substrate temperature 5

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Publication Date
Wed Feb 20 2019
Journal Name
Iraqi Journal Of Physics
Calculation the optical energy band gap of LR115 SSNTD irradiated by α particle
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The effect of α-particle irradiation on the optical absorption in nuclear track detectors (LR115) has been studied. These detectors have been irradiated with different doses. The optical absorption has been measured using the ultraviolet-visible (UV-1100) spectroscopy, that irradiation results in shifting the peaks of the optical absorption. The values of Urbach energy have been calculated from the position of steady-state optical band gap energy, for a standard sample which was unirradiated with indirect influence, has been found 1.9 eV  whereas its value after irradiation 1.98 eV. In case of the direct influence, it is found to be, respectively, before irradiation 1.98 eV and after irradiation 2.05 eV. From these results, we can

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Publication Date
Thu Sep 26 2013
Journal Name
Astronomy & Astrophysics
High-resolution observations of SDSS J080800.99+483807.7 in the optical and radio domains
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Publication Date
Fri Jan 01 2010
Journal Name
Advances In Condensed Matter Physics
Electrical and Optical Properties of :H Thin Films Prepared by Thermal Evaporation Method
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Thin a-:H films were grown successfully by fabrication of designated ingot followed by evaporation onto glass slides. A range of growth conditions, Ge contents, dopant concentration (Al and As), and substrate temperature, were employed. Stoichiometry of the thin films composition was confirmed using standard surface techniques. The structure of all films was amorphous. Film composition and deposition parameters were investigated for their bearing on film electrical and optical properties. More than one transport mechanism is indicated. It was observed that increasing substrate temperature, Ge contents, and dopant concentration lead to a decrease in the optical energy gap of those films. The role of the deposition conditions on value

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Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Role of External Audit in Limiting Creative Accounting Practices in Light of International Standards from The Point of View of Certified Accountancy Experts in Iraq as a Model
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This research aims to solve a problem in the field of accounting and financial knowledge in the world today, that is, the problem of creative accounting. Especially after the global financial crisis and the collapse of many large companies in the world, people find that they use creative accounting methods to distinguish them from reality, showing the results of their activities and their financial status. This research discusses the concept of creative accounting, the most important methods used in financial statements and its relationship with external auditing, and procedures to limit accounting creativity. This study uses descriptive analysis methods after confirming its theoretical aspects in practice. Using the statistical

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