Preferred Language
Articles
/
rheMnpEBVTCNdQwC-pYP
optical pulse propagation in photonic bandgap fiber Bragg grating
...Show More Authors

Abstract: In this work we demonstrate and investigate the optical pulse propagation in a photonic band gap fiber Bragg grating (FBG). The light propagates in opposite direction in FBG is explained and discussed by a Coupled Mode Theory (CMT). The photonic band gap (stop band gap) is created by fabricated, a Bragg grating in optical fiber. The results show the pulse spectrum falls entirely within the stop band gap, the entire pulse is reflected by the grating, while when the pulse spectrum is outside the stop band gap the pulses will transmitted through the grating. The group velocity (VG) becomes zero at the edges of the stop band and group velocity dispersion β2 is anomalous on the shorter side of stop band gap whereas β2 for uniform fiber becomes anomalous for wavelengths lower than the zero dispersion.

Preview PDF
Quick Preview PDF
Publication Date
Tue May 02 2023
Journal Name
Journal Of Optoelectronics And Advanced Materials
Preparation of samarium doped-PMMA composite by casting method to evaluate the optical properties and potential applications
...Show More Authors

Samarium ions (Sm +3), a rare-earth element, have a significant optical emission within the visible spectrum. PMMA samples, mixed with different ratios of SmCl3.6H2O, were prepared via the casting method. The composite was tested using UV-visible, photoluminescence and thermogravimetric analysis (TGA). The FTIR spectrometry of PMMA samples showed some changes, including variation in band intensity, location, and width. Mixed with samarium decreases the intensity of the CO and CH2 stretching bands and band position. A new band appeared corresponding to ionic bonds between samarium cations with negative branches in the polymer. These variations indicate complex links between the Sm +3 ion and oxygen in the ether group. The optical absorption

... Show More
Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Thickness on Some Optical Properties of Fe2O3 Thin Films Prepared by Chemical Spray Pyrolysis Technique
...Show More Authors

  The paper reports the influence of the thickness on the some optical properties of Fe2O3 thin films,which were prepared by chemical Spray  pyrolysis technique on glass substrate heated to 400Ëšc.The thickness of thin films (250,280,350)nm were measured by using weighting method. The optical properties include the absorbance and reflectance spectra,extinction coefficient,and real and imaginary part of the dielectric constant.The result  showed that the optical constant(k,εr,εi)decreased with the increase of the thickness.

View Publication Preview PDF
Publication Date
Sun Sep 06 2009
Journal Name
Baghdad Science Journal
Study of some structural , optical , Electrical Properties of CdS thin films deposited by chemical Spray Pyrolysis Method
...Show More Authors

In this research we prepared CdS thin films by Spray pyrolysis method on a glass substrates and we study its structural , optical , electrical properties .The result of (X-Ray ) diffraction showed that all thin films have a polycrystalline structure , The relation of the transmission as a function of wavelength for the CdS films had been studied , The investigated of direct energy gap of the CdS its value is (2.83 eV). In Hall effect measurement of the CdS we find the charge carriers is p – type and Hall coefficient 1157.33(cm3/c) ,Hall mobility 6.77(cm2/v.s)

View Publication Preview PDF
Crossref
Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
The Effect of annealing temperature on the optical properties of (Cu2S)100-x( SnS2 )x thin films
...Show More Authors

Thin films of (Cu2S)100-x( SnS2 )x at X=[ 30,40, &50)]% with thickness (0.9±0.03)µm , had been prepared by chemical spray pyrolysis method on glass substrates at 573 K. These films were then annealed under low pressure of(10-2) mbar ,373)423&473)K for one hour . This research includes , studying the the optical properties of (Cu2S)100-x-(SnS2)x at X=[ 30,40, &50)]% .Moreover studying the effect of annealing on their optical properties , in order to fabricate films with high stability and transmittance that can be used in solar cells. The transmittance and absorbance spectra had been recorded in the wavelength range (310 - 1100) nm in order to study the optical properties . It was found that these films had direct optical band

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 01 2020
Journal Name
Iraqi Journal Of Physics
Comparative study of the linear and nonlinear optical properties for different Iraqi heavy and light crude oils
...Show More Authors

Iraqi oil crudes have some of the physical and chemical characteristics that distinguish it from other types of oil crudes in the world. Some of these features such us molecular composition, rheological, viscosity and emulsions are studied carefully by researchers. In this work, a comparative study of the linear and the non-linear optical properties for typical heavy and light crude oils of Iraqi origin was studied utilizing Z-scan technique. The He -Ne laser of wavelength 632.8 nm had been used for this purpose. These samples were collected from Basra and Kut oil fields. The values of the non-linear refractive index (n2), non-linear absorption coefficient (β), and third-order electrical susceptibility (χ3) were e

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Influence of Gamma Radiation on Some Optical Properties and Urbach Energy of (PMMA- Doped Red Methyl) Films
...Show More Authors

  We have studied the effect of gamma irradiation on the optical transmission, absorbance, absorption coefficient,  and Urbach energy for (PMMA- doped red methyl) film deposited by using solvent casting method .The optical transmission (T %) in the wavelength range (1901100 ) nm of films was measured , it was seen that all the parameters were affected by gamma irradiation.

View Publication Preview PDF
Publication Date
Tue Aug 06 2024
Journal Name
Fullerenes, Nanotubes And Carbon Nanostructures
Preparation and characterization of PVA/MWCNT nanocomposites: a composition dependence study of structural, optical and mechanical properties
...Show More Authors

View Publication
Scopus (1)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Tue May 01 2018
Journal Name
Applied Surface Science
Structural, morphological, and optical characterizations of Mo, CrN and Mo:CrN sputtered coatings for potential solar selective applications
...Show More Authors

View Publication
Scopus (29)
Crossref (25)
Scopus Clarivate Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Ceramics International
Influence of DC magnetron sputtering reaction gas on structural and optical characteristics of Ce-oxide thin films
...Show More Authors

The influence of the reaction gas composition during the DC magnetron sputtering process on the structural, chemical and optical properties of Ce-oxide thin films was investigated. X-ray diffraction (XRD) studies confirmed that all thin films exhibited a polycrystalline character with cubic fluorite structure for cerium dioxide. X-ray photoelectron spectroscopy (XPS) analyses revealed that cerium is present in two oxidation states, namely as CeO2 and Ce2O3, at the surface of the films prepared at oxygen/argon flow ratios between 0% and 7%, whereas the films are completely oxidized into CeO2 as the aforementioned ratio increases beyond 14%. Various optical parameters for the thin films (including an optical band gap in the range of 2.25–3.

... Show More
View Publication
Scopus (21)
Crossref (20)
Scopus Clarivate Crossref
Publication Date
Sun May 01 2011
Journal Name
Thin Solid Films
Effect of temperature and deposition time on the optical properties of chemically deposited nanostructure PbS thin films
...Show More Authors

View Publication
Scopus (56)
Crossref (52)
Scopus Clarivate Crossref