Papers by Dr.Mohammed Fawzi Mohammed Altemimi
Optical and Quantum Electronics, Jun 8, 2023
Al-Nahrain Journal for Engineering Sciences, Dec 20, 2019
The effect of metal nanoparticles (MNPs) on the electric field strength and distribution for impr... more The effect of metal nanoparticles (MNPs) on the electric field strength and distribution for improvement solar cell performance is investigated and simulated. By manipulating the properties of nanoparticles, distribution of the electric field was altered. In this paper, classical solar cell (p-n junction) and improved structure (add an extra layer of SiO2 and gold nanoparticles on the top of p-n junction) is simulated. Different sizes of NPs, thickness of SiO2 sublayer, and spacing distance between NPs is done to improving the electric field and showing plamonic effect. Gold NPs deposition on single crystalline silicon solar cell is modelled by COMSOL 5.2 2D, Electromagnetic wave propagation in the frequency domain with periodic boundary conditions. The best wavelength found in our work is 550 nm. The electric field enhances when the size of NPs increases but it must be limited. When gold NPs are deposited on the SiO2 sublayer, the plasmonic effect appears due to decreasing the refractive index. Moreover, separation distance between NPs affect the electric field enhancement by manipulating the number of NPs, the distance decreases and the plasmonic interaction appears.
Optical and Quantum Electronics, Jun 8, 2023
Nucleation and Atmospheric Aerosols, 2021
2021 IEEE Jordan International Joint Conference on Electrical Engineering and Information Technology (JEEIT), 2021
Radio over fiber (RoF) OFDM with QAM modulation are key technologies enabling the new radio (NR) ... more Radio over fiber (RoF) OFDM with QAM modulation are key technologies enabling the new radio (NR) 5G and 6G backbone optical systems. A wavelength division multiplexing ROF OFDM architecture is investigated to enable higher capacity passive optical network for NR systems. Two DWDM wavelengths at 1931.1 and 193.2 THz are modulated with the downstream data. While another two dense wavelength division multiplexing (DWDM) continuous wave (CW) lasers at 193.16 and 193.26 THz are transmitted with the downstream data and modulated with the upstream data after amplified using a reflective semiconductor amplifier (RSOA). The upstream lasers are set at 60GHz off the downstream lasers typically used for mm waves. Different configurations of OFDM QAM and 16QAM systems are investigated in this work for different bit data rates and reaches. The study revealed that a10Gbps may be conveyed utilizing 4QAM and 16QAM modulation across 150 kilometers of fiber.
In this work, an analytical study to detect the ratio of bilirubin in human body by determining t... more In this work, an analytical study to detect the ratio of bilirubin in human body by determining the level of it in blood using a 532nm laser light transported through some samples of bilirubin has been presented. A second harmonic generation of Nd:YAG laser with measured maximum output power 52.5 mW was used to determine the concentration of total bilirubin in blood. Initially, the cuvette was filled with a sample of standard bilirubin level and then it is filled by a sample of blood containing unknown levels of bilirubin. The absorption factor was calculated for four samples of adults' blood and five samples of babies' blood, and the scattering factor was neglected for each sample. The unknown concentration of total bilirubin was determined and the transmitted power through these samples of blood was measured. In this work, a good matching was obtained between the results of the concentrations of bilirubin in blood using laser technique and the results of the classical medi...
مجلة النهرين للعلوم الهندسية, 2011
In this research, an analytical study of water using laser source transport through some samples ... more In this research, an analytical study of water using laser source transport through some samples of water tubes was presented. He Ne laser with measured maximum output power 2.83 mW was used to determine the purity of water by measuring its output power when it was passing through tube of water. This tube was initially filled by water and then by distill water contain different ratio of salts and clay. For each case, the output power would be measured and calculated its attenuation which was occurred when laser was passing through the water. The attenuation happened in the laser beam when transport through the water ample that contain NaCl due to the absorption process. The attenuation happened in the laser beam when transport through the water sample that contain clay due to the scattering process. Water tap mostly contain different ratio of salts and clay so the attenuation accurse in laser beam is due to absorption and scattering process, and it can be compared these results with...
AIP Conference Proceedings, 2021
In this paper, gold thin films were prepared on n-type region of solar cell in a method of plasma... more In this paper, gold thin films were prepared on n-type region of solar cell in a method of plasma sputtering technique with different thicknesses. The purpose is to enhance the conversion efficiency of single crystalline silicon solar cell compared to the bare cell. Different thicknesses of gold film 10 nm, 20 nm, and 30 nm were used to find the best thickness that improves efficiency. The obtained solar cell efficiency was (16.76 %) at (10 nm) thickness of gold film and (14.52 %) at (20 nm) whereas it was (4.64 %) for a bare solar cell. The reason for the high efficiency is the presence of free electrons in the nano-islands that disperse light when it falls on the gold film. This increases the amount of light entering the cell. The optical properties were also studied (absorbance, transmittance, and reflectance) of the gold thin film. The result showed that higher transmittance, less absorbance, and reflectance at a thickness of (10 nm).
Applied physics B laser and optics , 2022
A dynamic beam shaping method is proposed for the generation of flat top beams (FTBs) in the far ... more A dynamic beam shaping method is proposed for the generation of flat top beams (FTBs) in the far field. By using the mixed-region amplitude freedom algorithm, this new method is used to design the required phase distribution encoded on a spatial light modulator for the generation of FTB profiles. The characteristics of these new beam shaping methods are used as beam parameters, such as the laser beam size, the beam intensity of square FTBs, and the root-meansquare error (RMSE). By using our proposed method, the theoretical performance of beam intensity shaping is improved to an RMSE < 0.02 with a minimum number of iterations of phase reconstruction. Using the phase hologram of dynamic beam shaping, theoretical and experimental comparisons of edge steepness and plateau uniformity were established for the square FTBs of variable beam sizes. It is shown that the dynamic beam shaping of FTBs can produce high intensity uniformity in the plateau region with steep edges, which makes it an effective tool, especially for laser machining applications.
In this research, two computers are used to transfer data in free space optical communication sys... more In this research, two computers are used to transfer data in free space optical communication system using transmitter and receiver circuits and the distance separation between these computers is 50 m. The transmitter part of the optical communication system contains a drive circuit and semiconductor laser as a light source, while a receiver part of the optical communication system contains a phototransistor and an amplified circuit. In this research, we have designed and constructed an optical system of information transfer between two computers in practice based on the theoretical design circuits A green laser with wavelength of 532 nm and measured output power 26 mW is used. The COM port (RS-232) is used to send and receive data with “advanced serial port” program version 5.5 with a bit rate of 9600Kbps. The results of the optical communication system are achieved as sent a sequence of binary digit 0/1 from one computer to another computer using the measured transmitted power of ...
PROCEEDINGS OF THE III INTERNATIONAL CONFERENCE ON ADVANCED TECHNOLOGIES IN MATERIALS SCIENCE, MECHANICAL AND AUTOMATION ENGINEERING: MIP: Engineering-III – 2021, 2021
Al-Nahrain Journal for Engineering Sciences, 2019
The effect of metal nanoparticles (MNPs) on the electric field strength and distribution for impr... more The effect of metal nanoparticles (MNPs) on the electric field strength and distribution for improvement solar cell performance is investigated and simulated. By manipulating the properties of nanoparticles, distribution of the electric field was altered. In this paper, classical solar cell (p-n junction) and improved structure (add an extra layer of SiO2 and gold nanoparticles on the top of p-n junction) is simulated. Different sizes of NPs, thickness of SiO2 sublayer, and spacing distance between NPs is done to improving the electric field and showing plamonic effect. Gold NPs deposition on single crystalline silicon solar cell is modelled by COMSOL 5.2 2D, Electromagnetic wave propagation in the frequency domain with periodic boundary conditions. The best wavelength found in our work is 550 nm. The electric field enhances when the size of NPs increases but it must be limited. When gold NPs are deposited on the SiO2 sublayer, the plasmonic effect appears due to decreasing the refr...
Nahrain University, College of Engineering Journal (NUCEJ), 2011
In this research, an analytical study of water using laser source transport through some samples ... more In this research, an analytical study of water using laser source transport through some samples of water tubes was presented. He Ne laser with measured maximum output power 2.83 mW was used to determine the purity of water by measuring its output power when it was passing through tube of water. This tube was initially filled by water and then by distill water contain different ratio of salts and clay. For each case, the output power would be measured and calculated its attenuation which was occurred when laser was passing through the water. The attenuation happened in the laser beam when transport through the water sample that contain NaCl due to the absorption process. The attenuation happened in the laser beam when transport through the water sample that contain clay due to the scattering process. Water tap mostly contain different ratio of salts and clay so the attenuation accurse in laser beam is due to absorption and scattering process, and it can be compared these results with that produce when mixing NaCl solution sample with the clay sample.
International Journal of Current Engineering and Technology, 2014
In this research, two computers are used to transfer data in free space optical communication sys... more In this research, two computers are used to transfer data in free space optical communication system using transmitter and receiver circuits and the distance separation between these computers is 50 m. The transmitter part of the optical communication system contains a drive circuit and semiconductor laser as a light source, while a receiver part of the optical communication system contains a phototransistor and an amplified circuit. In this research, we have designed and constructed an optical system of information transfer between two computers in practice based on the theoretical design circuits A green laser with wavelength of 532 nm and measured output power 26 mW is used. The COM port (RS-232) is used to send and receive data with "advanced serial port" program version 5.5 with a bit rate of 9600Kbps. The results of the optical communication system are achieved as sent a sequence of binary digit 0/1 from one computer to another computer using the measured transmitted power of the laser at a specific distance between computers.
International Journal of Modern Engineering Research (IJMER), 2012
In this work, an analytical study to detect the ratio of bilirubin in human body by determining t... more In this work, an analytical study to detect the ratio of bilirubin in human body by determining the level of it in blood using a 532nm laser light transported through some samples of bilirubin has been presented. A second harmonic generation of Nd:YAG laser with measured maximum output power 52.5 mW was used to determine the concentration of total bilirubin in blood. Initially, the cuvette was filled with a sample of standard bilirubin level and then it is filled by a sample of blood containing unknown levels of bilirubin. The absorption factor was calculated for four samples of adults' blood and five samples of babies' blood, and the scattering factor was neglected for each sample. The unknown concentration of total bilirubin was determined and the transmitted power through these samples of blood was measured. In this work, a good matching was obtained between the results of the concentrations of bilirubin in blood using laser technique and the results of the classical medical procedure of measuring the bilirubin concentrations. Therefore, the jaundice in human was detected. I.
Al-Nahrain Journal for Engineering Sciences NJES, 2019
The effect of metal nanoparticles (MNPs) on the electric field strength and distribution for impr... more The effect of metal nanoparticles (MNPs) on the electric field strength and distribution for improvement solar cell performance is investigated and simulated. By manipulating the properties of nanoparticles, distribution of the electric field was altered. In this paper, classical solar cell (p-n junction) and improved structure (add an extra layer of SiO2 and gold nanoparticles on the top of p-n junction) is simulated. Different sizes of NPs, thickness of SiO2 sublayer, and spacing distance between NPs is done to improving the electric field and showing plamonic effect. Gold NPs deposition on single crystalline silicon solar cell is modelled by COMSOL 5.2 2D, Electromagnetic wave propagation in the frequency domain with periodic boundary conditions. The best wavelength found in our work is 550 nm. The electric field enhances when the size of NPs increases but it must be limited. When gold NPs are deposited on the SiO2 sublayer, the plasmonic effect appears due to decreasing the refractive index. Moreover, separation distance between NPs affect the electric field enhancement by manipulating the number of NPs, the distance decreases and the plasmonic interaction appears.
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Papers by Dr.Mohammed Fawzi Mohammed Altemimi