shehab kadhim - Academia.edu (original) (raw)

Papers by shehab kadhim

Journal of Engineering and Applied Sciences, Nov 30, 2019

An optical fiber sensors (OFS) is basically composed of a light source, an optical fiber serving ... more An optical fiber sensors (OFS) is basically composed of a light source, an optical fiber serving as a sensing element, and a detector. A method of sensing vibration using detection of changes in the spatial distribution of energy on the speckle pattern in the output multimode optical fiber is presented and demonstrated. The implementation of sensor consists of about10 meter active zone length of multimode fiber in a 3-mm cable housed inside half-inch conduit which is isolated and sensitive to ambient vibration. The projection of the speckle pattern is directly recorded by using Alarm Processing Unit type(FD322- APU) at the outlet end of the fiber and processed changes in the intensity distribution using supported algorithm (FD322-Tuning software).This paper presents the configuration and detection principles and characterization study of the a multimode optical fiber vibration or intrusion detection sensor based on registration of the speckle pattern in the far-field of a multimode optical fiber, and evaluates its performance as a fence sensor. It also describes the progress of our study on signal processing technology to prevent the sensor from issuing any false alarms or failing to issue alarms.

Experimental and Theoretical NANOTECHNOLOGY, Jan 15, 2021

Experimental and Theoretical NANOTECHNOLOGY

Surface Plasmon Resonance (SPR) is the charge density excitation oscillation (surface Plasmon’s, ... more Surface Plasmon Resonance (SPR) is the charge density excitation oscillation (surface Plasmon’s, (SP)) caused by the polarized light along with the metal-dielectric interface by agreeing to phase-matching condition between polarized light and SPR. SPR method has unusual advantages like label-free, real-time and high resolutions with less than 10-7 RIU which is not consenting with other sensing methods. Photonic Crystal Fiber (PCF) presents unique features like design elasticity, geometric flexible and extraordinary guiding mechanism which head for better performance contrast conventional optical fibre, Additionally, the presence of air holes gives the possibility to insert multi able materials, that can recognize the interaction of travelling light and materials operatively. Adding the advantages of PCF to the properties of SPR, lead to design very strong and unique devices in different applications. In this paper, the PCF sensor based on SPR technique had been presented. The inner ...

Mustansiriyah Journal for Sciences and Education, Jun 6, 2019

IOP Conference Series: Materials Science and Engineering, 2019

A new method of shifting in phase of optical heterodyne detection for humidity sensing have been ... more A new method of shifting in phase of optical heterodyne detection for humidity sensing have been proposed and demonstrated. In this paper, optical heterodyne techniques by using single source with single Fiber Brag Grating (FBG) were designed and studied. In this work FBG has been used as a light source and sensing element at the same time. FBG used as a laser source to achieve heterodyne detection through combine its reflected light with main laser source. Furthermore a combined lights was generated a beat frequency (F_B). The simulation results proved the ability of the proposed technique to achieve the requires sensitivity about 0.142 GHz / %RH.

IOP Conference Series: Materials Science and Engineering, 2019

Optical Heterodyne Detection (OHD) technique is based on two separate sources with optical interf... more Optical Heterodyne Detection (OHD) technique is based on two separate sources with optical interference between them. The optical signal from a specific light source is compared with a separate reference signal from another source. The Fiber Bragg grating (FBG) reflect a specific wavelength λ B and transmit the other wavelengths within the laser source spectral. This is achieved by changing the refractive index generated by periodic variation of optical fiber core, which reflect a specific wavelength, so FBG can be used to withhold a certain wavelength and allow other wavelengths to transmit. In this paper, a new method of an OHD has been designed using Optisystem software. Optical fiber as a temperature sensor element with single source and two FBGs have used in this system. the first FBG used as a tunable source and the other has used as a sensing element. The two optical signals have been combined utilizing a photodetector. It has a linear response to the light energy, while havi...

Al-Mustansiriyah Journal of Science, 2019

Many critical issues appear due to the exhaust gases from transportations facilities, electric ge... more Many critical issues appear due to the exhaust gases from transportations facilities, electric generators, industries, and so on. This lead to air pollution, which could be define as an introduction of biological materials or chemicals that’s causes harm to all living organism including humans. Also damaging the environment of earth. The principal gases that cause air pollution from these sources are nitrogen oxides (NO, NO2 and N2O) and carbon oxides (CO and CO2). There is a need to develop sensors that are characterized by highly-sensitive and miniaturize that capable of real-time analyses detection; optical fiber sensors agree with these needs. In this work, Large Mode Area- Polarization Maintaining Photonic Crystal Fiber (LMA-PM-PCF) for exhaust gases monitoring have been proposed to detect air-polluted gases over a wide transmission band covering (1µm) to (2µm) wavelength. Different guiding properties had been studied for the infiltrated PCFs. According to simulated results, th...

A standard Multimode optical fiber can be used as a general purpose spectrometer after calibratio... more A standard Multimode optical fiber can be used as a general purpose spectrometer after calibration the wavelength dependent speckle patterns produced by interference between the guided modes of the fiber. A theoretical analysis of the effects of the fiber geometry on the spectrometer performance, and then presents a reconstruction algorithm using a transmission matrix. Both fiber geometry and length have an effect on the spectral resolution and bandwidth, as well as the additional limitation on the bandwidth imposed by speckle patterns contrast reduction when measuring dense spectra is investigated. In a multimode fiber spectrometer, the interference between the guided modes creates a wavelength-dependent speckle patterns, providing the required spectral-to-spatial mapping. The advantage of using an optical fiber is that a long propagation length is easily achieved with minimal loss, giving high spectral resolution. Furthermore, the fiber-based spectrometer requires only a multimode...

Journal of Physics: Condensed Matter, 1994

Powder and foils containing up to 40% α''Fe 16 N 2 have been prepared by annealing nitrog... more Powder and foils containing up to 40% α''Fe 16 N 2 have been prepared by annealing nitrogen-martensite. The magnetization of the α'' phase is deduced from magnetization measurements, coupled with a quantitative phase analysis based on Mossbauer spectra. At room temperature the values are 225-270 J T -1 kg -1 corresponding to J s =2. 1-2.5 T. The average iron moment at T∼0 K is 2.3-2.6 μ B , which is in accord with the results of spin-polarized band structure calculations

Materials Today: Proceedings

Abstract The influence of doping the single mode fiber cladding and core with germanium (Ge) and ... more Abstract The influence of doping the single mode fiber cladding and core with germanium (Ge) and phosphorus (P) on the optical properties of fiber had been investigated in this work. This is done using the Finite Elements Method through the COMSOL Multiphysics simulation program. This study will be very helpful for designing optical fiber radiation sensors (Dosimeters) to investigate the influence of different -doping on the fiber sensitivity under different radiations like X-ray, pulsed X-ray, and Gamma-ray.

Journal of Materials Science: Materials in Medicine

The nanotechnology field plays an important role in the improvement of dental implant surfaces. H... more The nanotechnology field plays an important role in the improvement of dental implant surfaces. However, the different techniques used to coat these implants with nanostructured materials can differently affect cells, biomolecules and even ions at the nano scale level. The aim of this study is to evaluate and compare the structural, biomechanical and histological characterization of nano titania films produced by either modified laser or dip coating techniques on commercially pure titanium implant fixtures. Grade II commercially pure titanium rectangular samples measuring 35 × 12 × 0.25 mm length, width and thickness, respectively were coated with titania films using a modified laser deposition technique as the experimental group, while the control group was dip-coated with titania film. The crystallinity, surface roughness, histological feature, microstructures and removal torque values were investigated and compared between the groups. Compared with dip coating technique, the modified laser technique provided a higher quality thin coating film, with improved surface roughness values. For in vivo examinations, forty coated screw-designed dental implants were inserted into the tibia of 20 white New Zealand rabbits’ bone. Biomechanical and histological evaluations were performed after 2 and 4 weeks of implantation. The histological findings showed a variation in the bone response around coated implants done with different coating techniques and different healing intervals. Modified laser-coated samples revealed a significant improvement in structure, surface roughness values, bone integration and bond strength at the bone-implant interface than dip-coated samples. Thus, this technique can be an alternative for coating titanium dental implants.

Al-Mustansiriyah Journal of Science

Surface plasmon resonance (SPR) based fiber optic sensor with three types of bilayer configuratio... more Surface plasmon resonance (SPR) based fiber optic sensor with three types of bilayer configurations (silver/gold, copper/gold, and aluminum/gold) is theoretically analyzed. Performance parameters like sensitivity, signal to noise ratio, figure of merit, and resolution are evaluated for each configuration. Signal to noise ratio (SNR), and figure of merit (FOM) are enhanced very well for the selected bilayer configurations as the outer gold layer thickness increased, the sensitivity enhanced also but with small frictions while the resolution has decreased slightly.

2012 Annual IEEE India Conference (INDICON), 2012

Radio over Free Space Optics (RoFSO) and Radio over Fiber (RoF) are recent technologies in optica... more Radio over Free Space Optics (RoFSO) and Radio over Fiber (RoF) are recent technologies in optical communication systems. Both these technologies require some form of external optical modulator in the transmitter side. The commonly used optical modulators are Mach-Zehnder modulator (MZM) and Electro absorption modulator (EAM). In this paper, we analyze the performance of both Mach-Zehnder modulator and Electro absorption modulator for Radio over Free Space Optical Communication systems and it is compared with Radio over Fiber systems. We also discuss about the choice of optical modulator based on the intensity of output light signal.

The data rate on the order of gigabits per second of Free Space optical communication (FSO) syste... more The data rate on the order of gigabits per second of Free Space optical communication (FSO) system in turbulent channel suffers random fluctuations in the intensity and phase of the received signal. For mitigation of this effect, multiple input multiple output (MIMO-FSO) system performance with spatial diversity overatmospheric turbulence channels was considered in this work. Obtained results demonstrate that MIMO performance mitigation techniques have high link availability and reliability of FSO system under wide range of atmospheric turbulence conditions.Data rate enhances results are achieved without any bandwidth or power expansions and the bit error rate (BER) at the receiver is maintained below 10 −9. We assume intensity modulation and on-off keying with NRZ type and present the BER performance of single-input single-output (SISO-FSO), (2Tx × 2Rx) and (4Tx × 4Rx) (MIMO-FSO) configuration systems with (155 Mbps) over this channel model. Both techniques of FSO systems (SISO and...

Journal of Physics: Conference Series

In this work, based on Mach- Zehender Interferometry (MZI) technique, a single-mode optical fiber... more In this work, based on Mach- Zehender Interferometry (MZI) technique, a single-mode optical fiber had been designed as a water pollution sensor. The submitted sensor had been designed to detect pollutants in water. The sodium chloride salt and sugar were used as simulation examples of pollutants with different concentrations (0-0.45) mol /liter. The performance of the submitted sensor had been studied for different sensor arm diameters which were (63.5, 51.58, 39.68 and 20 µm). The variation of the refractive index of salty and sugary solutions surrounding the sensor leads to a change in the optical properties of the transmitted signal. In this work, a wavelength shifting had been obtained due to this variation. The influence of sensor diameter on the sensitivity of the system had been studied. From the results, we found that the higher sensitivity was for the sensors with a diameter of 20 µm, and they were 1130 pm/mol.l-1 and 1205 pm/mol.l-1 for salty and sugary solution respectively.

Recent digital fiber optic communication systems address modulation and detection techniques for ... more Recent digital fiber optic communication systems address modulation and detection techniques for high spectral efficiency and robustness against transmission impairments. The proposed objective of this project is to design studies and analyze the simulation model of a Digital Fiber Communication System using (optisystem.10), as well as the front-end components and units used to implement them. Using the most suitable settings of the system which include laser transmitter with (1310nm) and (1550nm) wavelengths as input power (dBm), optical fiber with both (SM and MM) cable types as channel length (km),(RZ and NRZ) modulationand demodulation schemes to maximize spectral efficiency and power efficiency by encoding information are analyzed in order to evaluate their penalization over the signal qualityat the receiver.There are three different parameters will be investigated which are output power (dBm), noise figure (dB), and transmittance for the two types of fibers .

Iraqi Journal of Science

In this work, the performance of single-mode optical fibers (SMFs) for ultraviolet (UV) rad... more In this work, the performance of single-mode optical fibers (SMFs) for ultraviolet (UV) radiation monitoring and dosimetry applications is presented. In particular, this work will focus on the Radiation-Induced Absorption (RIA) phenomena in the Near-Infrared domain (NIR). Such phenomena play a very important role in the sensing mechanism for SMF. Single mode fibers with a diameter of 50 µm were used for this purpose. These fibers were dipped into germanium (Ge) solution with different concentrations (1, 3, and 5 wt%) to produce the sensing part of the sensor. For all optical fiber sensors under investigation, the results indicated the dependence of the RIA on the applied UV radiation energy. Also, a redshift in peak wavelength was obtained. The influence of Ge concentration on sensing efficiency was studied and the best results were obtained with 3 wt% concentration as compared to 1 wt % and 5 wt % concentrations. The presented sensor shows good sensitivity to UV radiation whi...

Scattering of the light photons by different aerosols attenuate the free space optical (FSO) prop... more Scattering of the light photons by different aerosols attenuate the free space optical (FSO) propagation that hinders network deployment due to loss of the line of sight (LoS). In this paper, the atmospheric turbulence effects on active receiving area of the Full Free Space Optical (FFSO) communication systems was investigated. From the results, it has been shown that if the number of integrated fiber optics receiver increases, the BER enhance and the performance of FSO links are improved both in the weak and strong turbulence condition.

Journal of Engineering and Applied Sciences, Nov 30, 2019

An optical fiber sensors (OFS) is basically composed of a light source, an optical fiber serving ... more An optical fiber sensors (OFS) is basically composed of a light source, an optical fiber serving as a sensing element, and a detector. A method of sensing vibration using detection of changes in the spatial distribution of energy on the speckle pattern in the output multimode optical fiber is presented and demonstrated. The implementation of sensor consists of about10 meter active zone length of multimode fiber in a 3-mm cable housed inside half-inch conduit which is isolated and sensitive to ambient vibration. The projection of the speckle pattern is directly recorded by using Alarm Processing Unit type(FD322- APU) at the outlet end of the fiber and processed changes in the intensity distribution using supported algorithm (FD322-Tuning software).This paper presents the configuration and detection principles and characterization study of the a multimode optical fiber vibration or intrusion detection sensor based on registration of the speckle pattern in the far-field of a multimode optical fiber, and evaluates its performance as a fence sensor. It also describes the progress of our study on signal processing technology to prevent the sensor from issuing any false alarms or failing to issue alarms.

Experimental and Theoretical NANOTECHNOLOGY, Jan 15, 2021

Experimental and Theoretical NANOTECHNOLOGY

Surface Plasmon Resonance (SPR) is the charge density excitation oscillation (surface Plasmon’s, ... more Surface Plasmon Resonance (SPR) is the charge density excitation oscillation (surface Plasmon’s, (SP)) caused by the polarized light along with the metal-dielectric interface by agreeing to phase-matching condition between polarized light and SPR. SPR method has unusual advantages like label-free, real-time and high resolutions with less than 10-7 RIU which is not consenting with other sensing methods. Photonic Crystal Fiber (PCF) presents unique features like design elasticity, geometric flexible and extraordinary guiding mechanism which head for better performance contrast conventional optical fibre, Additionally, the presence of air holes gives the possibility to insert multi able materials, that can recognize the interaction of travelling light and materials operatively. Adding the advantages of PCF to the properties of SPR, lead to design very strong and unique devices in different applications. In this paper, the PCF sensor based on SPR technique had been presented. The inner ...

Mustansiriyah Journal for Sciences and Education, Jun 6, 2019

IOP Conference Series: Materials Science and Engineering, 2019

A new method of shifting in phase of optical heterodyne detection for humidity sensing have been ... more A new method of shifting in phase of optical heterodyne detection for humidity sensing have been proposed and demonstrated. In this paper, optical heterodyne techniques by using single source with single Fiber Brag Grating (FBG) were designed and studied. In this work FBG has been used as a light source and sensing element at the same time. FBG used as a laser source to achieve heterodyne detection through combine its reflected light with main laser source. Furthermore a combined lights was generated a beat frequency (F_B). The simulation results proved the ability of the proposed technique to achieve the requires sensitivity about 0.142 GHz / %RH.

IOP Conference Series: Materials Science and Engineering, 2019

Optical Heterodyne Detection (OHD) technique is based on two separate sources with optical interf... more Optical Heterodyne Detection (OHD) technique is based on two separate sources with optical interference between them. The optical signal from a specific light source is compared with a separate reference signal from another source. The Fiber Bragg grating (FBG) reflect a specific wavelength λ B and transmit the other wavelengths within the laser source spectral. This is achieved by changing the refractive index generated by periodic variation of optical fiber core, which reflect a specific wavelength, so FBG can be used to withhold a certain wavelength and allow other wavelengths to transmit. In this paper, a new method of an OHD has been designed using Optisystem software. Optical fiber as a temperature sensor element with single source and two FBGs have used in this system. the first FBG used as a tunable source and the other has used as a sensing element. The two optical signals have been combined utilizing a photodetector. It has a linear response to the light energy, while havi...

Al-Mustansiriyah Journal of Science, 2019

Many critical issues appear due to the exhaust gases from transportations facilities, electric ge... more Many critical issues appear due to the exhaust gases from transportations facilities, electric generators, industries, and so on. This lead to air pollution, which could be define as an introduction of biological materials or chemicals that’s causes harm to all living organism including humans. Also damaging the environment of earth. The principal gases that cause air pollution from these sources are nitrogen oxides (NO, NO2 and N2O) and carbon oxides (CO and CO2). There is a need to develop sensors that are characterized by highly-sensitive and miniaturize that capable of real-time analyses detection; optical fiber sensors agree with these needs. In this work, Large Mode Area- Polarization Maintaining Photonic Crystal Fiber (LMA-PM-PCF) for exhaust gases monitoring have been proposed to detect air-polluted gases over a wide transmission band covering (1µm) to (2µm) wavelength. Different guiding properties had been studied for the infiltrated PCFs. According to simulated results, th...

A standard Multimode optical fiber can be used as a general purpose spectrometer after calibratio... more A standard Multimode optical fiber can be used as a general purpose spectrometer after calibration the wavelength dependent speckle patterns produced by interference between the guided modes of the fiber. A theoretical analysis of the effects of the fiber geometry on the spectrometer performance, and then presents a reconstruction algorithm using a transmission matrix. Both fiber geometry and length have an effect on the spectral resolution and bandwidth, as well as the additional limitation on the bandwidth imposed by speckle patterns contrast reduction when measuring dense spectra is investigated. In a multimode fiber spectrometer, the interference between the guided modes creates a wavelength-dependent speckle patterns, providing the required spectral-to-spatial mapping. The advantage of using an optical fiber is that a long propagation length is easily achieved with minimal loss, giving high spectral resolution. Furthermore, the fiber-based spectrometer requires only a multimode...

Journal of Physics: Condensed Matter, 1994

Powder and foils containing up to 40% α''Fe 16 N 2 have been prepared by annealing nitrog... more Powder and foils containing up to 40% α''Fe 16 N 2 have been prepared by annealing nitrogen-martensite. The magnetization of the α'' phase is deduced from magnetization measurements, coupled with a quantitative phase analysis based on Mossbauer spectra. At room temperature the values are 225-270 J T -1 kg -1 corresponding to J s =2. 1-2.5 T. The average iron moment at T∼0 K is 2.3-2.6 μ B , which is in accord with the results of spin-polarized band structure calculations

Materials Today: Proceedings

Abstract The influence of doping the single mode fiber cladding and core with germanium (Ge) and ... more Abstract The influence of doping the single mode fiber cladding and core with germanium (Ge) and phosphorus (P) on the optical properties of fiber had been investigated in this work. This is done using the Finite Elements Method through the COMSOL Multiphysics simulation program. This study will be very helpful for designing optical fiber radiation sensors (Dosimeters) to investigate the influence of different -doping on the fiber sensitivity under different radiations like X-ray, pulsed X-ray, and Gamma-ray.

Journal of Materials Science: Materials in Medicine

The nanotechnology field plays an important role in the improvement of dental implant surfaces. H... more The nanotechnology field plays an important role in the improvement of dental implant surfaces. However, the different techniques used to coat these implants with nanostructured materials can differently affect cells, biomolecules and even ions at the nano scale level. The aim of this study is to evaluate and compare the structural, biomechanical and histological characterization of nano titania films produced by either modified laser or dip coating techniques on commercially pure titanium implant fixtures. Grade II commercially pure titanium rectangular samples measuring 35 × 12 × 0.25 mm length, width and thickness, respectively were coated with titania films using a modified laser deposition technique as the experimental group, while the control group was dip-coated with titania film. The crystallinity, surface roughness, histological feature, microstructures and removal torque values were investigated and compared between the groups. Compared with dip coating technique, the modified laser technique provided a higher quality thin coating film, with improved surface roughness values. For in vivo examinations, forty coated screw-designed dental implants were inserted into the tibia of 20 white New Zealand rabbits’ bone. Biomechanical and histological evaluations were performed after 2 and 4 weeks of implantation. The histological findings showed a variation in the bone response around coated implants done with different coating techniques and different healing intervals. Modified laser-coated samples revealed a significant improvement in structure, surface roughness values, bone integration and bond strength at the bone-implant interface than dip-coated samples. Thus, this technique can be an alternative for coating titanium dental implants.

Al-Mustansiriyah Journal of Science

Surface plasmon resonance (SPR) based fiber optic sensor with three types of bilayer configuratio... more Surface plasmon resonance (SPR) based fiber optic sensor with three types of bilayer configurations (silver/gold, copper/gold, and aluminum/gold) is theoretically analyzed. Performance parameters like sensitivity, signal to noise ratio, figure of merit, and resolution are evaluated for each configuration. Signal to noise ratio (SNR), and figure of merit (FOM) are enhanced very well for the selected bilayer configurations as the outer gold layer thickness increased, the sensitivity enhanced also but with small frictions while the resolution has decreased slightly.

2012 Annual IEEE India Conference (INDICON), 2012

Radio over Free Space Optics (RoFSO) and Radio over Fiber (RoF) are recent technologies in optica... more Radio over Free Space Optics (RoFSO) and Radio over Fiber (RoF) are recent technologies in optical communication systems. Both these technologies require some form of external optical modulator in the transmitter side. The commonly used optical modulators are Mach-Zehnder modulator (MZM) and Electro absorption modulator (EAM). In this paper, we analyze the performance of both Mach-Zehnder modulator and Electro absorption modulator for Radio over Free Space Optical Communication systems and it is compared with Radio over Fiber systems. We also discuss about the choice of optical modulator based on the intensity of output light signal.

The data rate on the order of gigabits per second of Free Space optical communication (FSO) syste... more The data rate on the order of gigabits per second of Free Space optical communication (FSO) system in turbulent channel suffers random fluctuations in the intensity and phase of the received signal. For mitigation of this effect, multiple input multiple output (MIMO-FSO) system performance with spatial diversity overatmospheric turbulence channels was considered in this work. Obtained results demonstrate that MIMO performance mitigation techniques have high link availability and reliability of FSO system under wide range of atmospheric turbulence conditions.Data rate enhances results are achieved without any bandwidth or power expansions and the bit error rate (BER) at the receiver is maintained below 10 −9. We assume intensity modulation and on-off keying with NRZ type and present the BER performance of single-input single-output (SISO-FSO), (2Tx × 2Rx) and (4Tx × 4Rx) (MIMO-FSO) configuration systems with (155 Mbps) over this channel model. Both techniques of FSO systems (SISO and...

Journal of Physics: Conference Series

In this work, based on Mach- Zehender Interferometry (MZI) technique, a single-mode optical fiber... more In this work, based on Mach- Zehender Interferometry (MZI) technique, a single-mode optical fiber had been designed as a water pollution sensor. The submitted sensor had been designed to detect pollutants in water. The sodium chloride salt and sugar were used as simulation examples of pollutants with different concentrations (0-0.45) mol /liter. The performance of the submitted sensor had been studied for different sensor arm diameters which were (63.5, 51.58, 39.68 and 20 µm). The variation of the refractive index of salty and sugary solutions surrounding the sensor leads to a change in the optical properties of the transmitted signal. In this work, a wavelength shifting had been obtained due to this variation. The influence of sensor diameter on the sensitivity of the system had been studied. From the results, we found that the higher sensitivity was for the sensors with a diameter of 20 µm, and they were 1130 pm/mol.l-1 and 1205 pm/mol.l-1 for salty and sugary solution respectively.

Recent digital fiber optic communication systems address modulation and detection techniques for ... more Recent digital fiber optic communication systems address modulation and detection techniques for high spectral efficiency and robustness against transmission impairments. The proposed objective of this project is to design studies and analyze the simulation model of a Digital Fiber Communication System using (optisystem.10), as well as the front-end components and units used to implement them. Using the most suitable settings of the system which include laser transmitter with (1310nm) and (1550nm) wavelengths as input power (dBm), optical fiber with both (SM and MM) cable types as channel length (km),(RZ and NRZ) modulationand demodulation schemes to maximize spectral efficiency and power efficiency by encoding information are analyzed in order to evaluate their penalization over the signal qualityat the receiver.There are three different parameters will be investigated which are output power (dBm), noise figure (dB), and transmittance for the two types of fibers .

Iraqi Journal of Science

In this work, the performance of single-mode optical fibers (SMFs) for ultraviolet (UV) rad... more In this work, the performance of single-mode optical fibers (SMFs) for ultraviolet (UV) radiation monitoring and dosimetry applications is presented. In particular, this work will focus on the Radiation-Induced Absorption (RIA) phenomena in the Near-Infrared domain (NIR). Such phenomena play a very important role in the sensing mechanism for SMF. Single mode fibers with a diameter of 50 µm were used for this purpose. These fibers were dipped into germanium (Ge) solution with different concentrations (1, 3, and 5 wt%) to produce the sensing part of the sensor. For all optical fiber sensors under investigation, the results indicated the dependence of the RIA on the applied UV radiation energy. Also, a redshift in peak wavelength was obtained. The influence of Ge concentration on sensing efficiency was studied and the best results were obtained with 3 wt% concentration as compared to 1 wt % and 5 wt % concentrations. The presented sensor shows good sensitivity to UV radiation whi...

Scattering of the light photons by different aerosols attenuate the free space optical (FSO) prop... more Scattering of the light photons by different aerosols attenuate the free space optical (FSO) propagation that hinders network deployment due to loss of the line of sight (LoS). In this paper, the atmospheric turbulence effects on active receiving area of the Full Free Space Optical (FFSO) communication systems was investigated. From the results, it has been shown that if the number of integrated fiber optics receiver increases, the BER enhance and the performance of FSO links are improved both in the weak and strong turbulence condition.