Print ISSN: 1681-6900

Online ISSN: 2412-0758

Main Subjects : Laser


The Fundamental of Reduced Graphene Oxide with Nanosilver Composite Films Using the Spin Coating Technique

Hamsa A. Alaloosi; Farah T. M. Noori; Abdulhadi K. Jidran

Engineering and Technology Journal, 2022, Volume 40, Issue 8, Pages 120-129
DOI: 10.30684/etj.v40i8.2205

Graphene oxide synthesis by hummers method and reduction by the green chemical method using green tea. Preparation films with reduced graphene oxide (rGO) and Silver Nanoparticles (AgNPs) by a spin coating method. The preparation films and Nanomaterial characteristics with X-Ray diffraction (XRD) GO has a peak at (2θ = 11.22̊ ). While rGO has a wider peak at (2θ = 26.2̊ ). The (rGO +AgNPs) films have five obvious diffraction angles. In Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), flaky sheet (rGO), and spherical (AgNPs) with Nanosize about ~20 nm, the peaks of EDX indicated the presence of Carbon, silver, and oxygen. The energy gap was calculated from the absorbance spectrum and seemed to decrease with increasing AgNPs.

The Visual Quality of Healthy Eye Lens for Different Tilt Effects

Laith A. Tawfeeq; Ali H. Al-Hamdani

Engineering and Technology Journal, 2022, Volume 40, Issue 8, Pages 130-139
DOI: 10.30684/etj.v40i8.2197

The importance and accuracy of the human visual system have led scientists and researchers to do their best to study it, know its problems, and how to treat them.
The eye lens tilt is possibly due to a specific accident such as a blow or the like. So, this manuscript was submitted to study the human eye lens tilting effect on visual performance and determine the tolerance tilt values. Using (ZEMAX-EE) software program and relying on the Liou and Brennan model Eye (LBME), one of the most accurate models for studying the eye, and some basic criteria used to describe the image formed in an optical system, such as Modulation Transfer Function (MTF), Root Main Square-spot size (RMSS), and simulated image including aberration, the study of the lens tilt effect on visual quality was conducted. The calculation of the area under the MTF curve was also used to determine the tolerance tilt values. Where the lens was tilted from (-5 to 5) degrees by (1 degree) on the (X and Y) axes, for zero decentering, with visible wavelength (0.486, 0.587, 0.656) µm, pupil diameter (2.5 mm), and field of view (5o).The results were that vision worsened when the lens was tilted due to reduced MTF. Sagittal MTF was less sensitive than Tangential due to the nature of the lens structure. The area under the MTF curve results also proved that the tilt is less than (5) degrees does not affect the visual much, so it was necessary to determine the tilt tolerance values.It was concluded that the visual quality was inversely proportional to the tilt increase. Exceeding the tilt (5) degrees led to visual deterioration due to increased optical aberration where the tolerance tilt ranges were (± 5.1) degrees and (- 5.9 to 9) degrees on the (x and y) axes, respectively.

Theory and Modeling of Slab Waveguide Based Surface Plasmon Resonance

Amnah S. Hasan; Razi J. Al-azawi; Ali A. Alwahib

Engineering and Technology Journal, 2022, Volume 40, Issue 8, Pages 1-8
DOI: 10.30684/etj.2022.132295.1100

 The current study proposes a developing surface plasmon resonance (SPR) sensor that has been widely employed to detect viruses, such as environmental analytes, biological and chemical analytes, and monitoring and medical diagnostics. Optical waveguides have much potential for developing new chemical and biological sensors. Graphene is the world's most vital substance and can be used to enhance other materials. A composite silver film-based SPR sensor with the waveguide. To enhance the silver film's stability, detect the best thickness with the best resonance using different types of analyte: air than 1.1, 1.2, 1.3, and water. The resonance wavelength numerically calculated, loss, sensitivity, Figure of merit FOM, and Refractive index using Lumerical FDE. The numerical data showed the differences in the electric field of SPR in the number of refractive indexes after applying the silver coating layer, and the performance parameters improved. Moreover, Graphene has much promise, yet almost most of it is still unexplored. The fundamentals of graphene-based waveguides and devices were investigated using two layers with FDE. The primary purpose of this study is to show the effective thickness of the Graphene and the analyte's refractive index to get high absorption.

Numerical Simulation of the Self-Imaging at Different Cascaded Optical Fiber Specifications

Shahad I. Younus; Anwaar A Al-Dergazly; Abdulla K. Abass

Engineering and Technology Journal, 2022, Volume 40, Issue 2, Pages 412-421
DOI: 10.30684/etj.v40i2.2236

Cascaded optical fiber single mode-no core-single mode fiber (SNS) attracted attention for being the base of various photonic devices. These devices are used in optical communication, fiber sensors, and fiber laser technology. The effect of variable NCF specifications, length, diameter, external refractive index (ERI), propagating wavelength on the self-imaging position, and the multimode interference (MMI) is studied. The study aims to simulate and analyze cascaded optical fiber by using the finite element beam envelope method (BEM). To the best of our knowledge, this is the first report that studied the self-imaging in cascaded optical fiber longitudinally by using BEM. The NCF length is important in determining the coupled out intensity and peak transmission wavelength. The field in the cascaded fiber is simulated for single and multi-wavelengths to evaluate the maximum transmission and study the structure's tunability. A tunable filter is simulated, where varying the length of the NCF about 0.6 mm produces a wavelength shift of about 40 nm. The BEM is effective in studying the field propagation in large guiding photonic devices

Physical Properties of Pure Gold Nanoparticles and Gold Doped ZnO Nanoparticles Using Laser Ablation in Liquid For Sensor Applications

Nabaa K. Hassan; Makram A Fakhri; Evan T. Salim

Engineering and Technology Journal, 2022, Volume 40, Issue 2, Pages 422-427
DOI: 10.30684/etj.v40i2.2242

In this paper, the effect of using laser ablation of pure gold targets to obtain gold Nano rods and for pure zinc targets to obtain zinc oxide nanoparticles was studied separately in ethanol using an Nd:YAG laser tattoo removal (nanosecond pulses) and then mixing the resulting mixtures to obtain gold dopant with zinc oxide. Transmission electron microscopy (TEM), (XRD) X-Ray Diffraction and the optical properties were used to characterize the pure gold Nano rods, ZnO nanoparticles, and Au doped ZnO nanoparticles. Based on XRD and TEM, the results revealed the properties of the produced gold Nano roads. The obtained results indicated that the gold Nano rods produced by the 1064nm laser have superior optical, structural, and morphological properties and can be used in different sensors.

Performance Comparison of Serial and Parallel Hybrid Fiber Amplifier under Optimum Pump Conditions

aseel ali Khudhaier; Abdulla K. Abass; Mudhafer H. Ali

Engineering and Technology Journal, 2022, Volume 40, Issue 2, Pages 428-432
DOI: 10.30684/etj.v40i2.2183

In this work, two different configurations of hybrid fiber optic amplifiers are investigated and simulated via OptiSystem 7.0 software, namely, serial and parallel hybrid fiber optical amplifiers (S– and P–HFOAs). The investigation involves performance comparison for the S– and P–HFOA under optimum pump conditions to demonstrate the advantages and disadvantages of each configuration. The simulation results show that the serial configuration has a high average gain level of 19.2 dB, an appropriate noise figure about 4.3 dB, but low saturation power, and limited gain bandwidth of approximately 40 nm, which is considered a primary issue in S–HOFA design, in addition to the pump conversion efficiency still insufficient in the Raman amplifier stage. While in P–HFOA design, a wide 3–dB gain bandwidth of more than 60 nm is maintained, along with an average gain level of  13.5 dB, high average noise figure about 8.3 dB and high saturation power due to the absent of cascading effect in parallel configuration

Pentacene Based Organic Field Effect Transistor Using Different Gate Dielectric

Ayat Kadhim; Estabraq Abdullah; Abdulhadi K. Judran

Engineering and Technology Journal, 2021, Volume 39, Issue 11, Pages 1688-1692
DOI: 10.30684/etj.v39i11.2075

This paper presents the electrical behavior of the top contact/ bottom gate of an organic field-effect transistor (OFET) utilizing Pentacene as a semiconductor layer with two distinctive gate dielectric materials Polyvinylpyrrolidone (PVP) and Zirconium oxide (ZrO2) were chosen. The influence of the monolayer and bilayer gates insulator on OFET performance was investigated. MATLAB software was used to simulate and determine the electrical characteristics of a device. The output and transfer characteristics were studied for ZrO2, PVP and ZrO2/PVP as an organic gate insulator layer. Both characteristics show a high drain current at the gate dielectric ZrO2/PVP equal to -0.0031A and -0.0015A for output and transfer characteristics respectively, this can be attributed to an increase in the dielectric capacitance. Trans conductance characteristics also studied the gate dielectric materials and show the ZrO2/PVP gate dielectric having a higher value from the monolayer, indicating the effect of dielectric capacitance.