Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Optical


Investigation of Structural, Optical and Electrical Properties of ZnO Prepared Thin Film by PLD

Samer. Y. Al-Dabag

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 838-847

In this paper , Zinc Oxide (ZnO) films were grown on glass substrates by Pulsed Laser Deposition (PLD) technique at room temperature under the vacuum pressure of 3×10−3 mbar. Employing a Nd:YAG pulses laser at wavelength 1064nm was used in this technique .The effect of number of laser pulses (200,500 and 800) at annealing temperature450C oon the structural, optical and electrical properties was studied.The structure of the ZnO thin films was examined by X-Ray diffraction (XRD), it was found thatZnO thin films arepolycrystalline with many peaks, and the results of Atomic Force Microscopy (AFM) indicated that all films have grain size around 90 nm.The optical properties concerning the photoluminescence (PL) spectra were studied for the prepared thin film. From the PL, the optical gap of the ZnO thin film was determined. The Hall effect measurements confirmed that the ZnO thin films are n-type , While the number of laser pulses is increasing, the charge carriers concentration (n) increases, and Hall mobility (H) decreases.

Optical and Morphological Property of Ag Nanoparticles by Laser Ablation in Double Distilled and Deionized Water

Amenah Ali Salman

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 938-942

Noble metal silver NPs was synthesized by pulsed (Q-switched, 1064 nm Nd : YAG) laser ablation of silver metal plates immersed in double distilled and deionized water DDDW.
The formation efficiency of PLAL process was quantified in term of the surface Plasmon extinction SPE peaks. The SPE spectra show a sharp and single peak around 400 nm, indicating the production of pure and spherical Ag.
UV-Visible absorption results confirmed formation of silver particles prepared and atomic force microscope (AFM) indicates the size in nanometer (nm) range.

Structural and Optoelectronical Properties of In2S3 Thin Films Prepared by CSP Technique for Solar Cell Application

Baha. T. Chiad; M. Sh. Essa; M.D.Abd-aljabar; J.A.Abd-aula

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 629-636

Indium Sulfide In2S3 window layer have been prepared by Chemical Spray Pyrolysis (CSP) at substrate temperate Equal (573 K) from Indium chloride and Thiourea were In/S ratio equal 1.2/8 in the spray solution, the samples prepared with different thicknesses (1.6, 1.7, 2.0 µm), the structural, optical and electrical of these films was investigated at different annealing temperature (Ta).X-ray diffraction studied shows the Structural properties of this layer are polycrystalline with preferred orientation 221, and have good improvement in the crystal structure at the annealing temperature (573K for 1h). The grain size increase with increasing annealing temperature and the optical band gap was found in the range (2.4-2.55 eV) as a function of the film thicknesses and the annealing temperature. Electrical studied of the sprayed and annealed sample shows n-type electrical conductivity, the mobility improved at the annealing temperature equal (573 K) but the resistivity decreased with this temperature.

NUMERICAL SIMULATION FOR HIGH- SPEED ALL- OPTICAL BOOLEAN GATES

Inmar N. Ghazi

Engineering and Technology Journal, 2008, Volume 26, Issue 9, Pages 1143-1157

In this paper few high speed (i.e. as high as 80 GB/s) all-optical logic gates has been studied.
These logic gates include a ( 80Gb/s XOR ) gate using semiconductor optical amplifier (SOA)
based Mach-Zehnder interferometer incorporated with a delayed interferometer (DI), The
performance of XOR operation has been investigated using numerical simulations. The quality of
the XOR result is improved using a (DI) delayed interferometer after the Mach-Zehnder
interferometer. . A (80Gb/s XNOR) gate using four wave mixing (FWM) in highly nonlinear
fibers (HNLF) have been studied also, the four wave mixing process is a very fast process in
fibers ,the nonlinear Schrödinger equation that describes (FWM) process in fiber is solved
numerically using the split-step Fourier transform method ,this scheme is capable of operating at
a data rate as high as 250Gb/s ,finally A(40Gb/s) NOR gate operation has been analyzed by a
numerical solution of the SOA rate equations. To investigate the quality of NOR operation by
simulation, Q factor of the NOR output signal has been calculated. Q factor gives the information
of the optical signal to noise ratio in digital transmission .All numerical simulation programs
performed through Matt-Lab 7.0 prgram.