Abulla Khudiar Abass

Abulla Khudiar Abass
University of Technology, Iraq · Department of Laser Engineering and Electronic Optics

Assist. Prof. Dr. Optical Communication

About

67
Publications
12,219
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
283
Citations
Additional affiliations
May 2011 - present
Universiti Tenaga Nasional (UNITEN)
Position
  • PhD Student
April 2004 - present
University of Technology, Iraq
Position
  • Lecturer
January 2004 - present
University of Technology
Position
  • Lecturer

Publications

Publications (67)
Article
Full-text available
In this paper, for the first time to the best of our knowledge, a high bit rate of 40 Gb/s wavelength division multiplexing based on a secure free space optical communication system by utilizing an optical chaos. The optical chaos was designed and investigated via OptiSystem-7.0 software. The signal message was hidden by applying the optical chaos...
Article
Full-text available
In this work, the performance of wavelength division multiplexing based radio over free space optics (WDM-RoFSO) communication system is investigated utilizing OptiSystem 0.7 software. Four weather conditions are adopted in this paper, namely, clear, haze, rain and fog with attenuation losses of 0.2 dB/km, 2.3 dB/km, 4.3 dB/km and 8 dB/km, respecti...
Article
The pulsed laser deposition (PLD) technique was used to deposit a lithium niobate (LN) layer on a single crystal silicon substrate in this study. Based on the properties of LN film, a design and modeling of Mach-Zehnder electro-optic modulators (EOM) has been presented. The LiNbO3/SiO2/Si system’s structural, morphological, and optical characterist...
Article
The performance parameters for both Sand P-HFOA were simulated and compared at OPP via OptiSystem software.  The S-HFOA has a high average gain and an appropriate NF, but the gain bandwidth is limited.  The P-HFOA has a wide 3-dB gain bandwidth and high saturation power as compared to the S-HFOA.. In this work, two different configurations of hyb...
Article
Full-text available
The simulation and investigation of a 32 × 10 Gb/s WDM all-optical bidirectional hybrid communication system for outdoor applications is presented in this article via multidisciplinary softwares. In order to track the system condition, a strain sensor based on fiber Bragg grating (FBG) is integrated in-line with the fiber optic link (FO-link). Then...
Preprint
Full-text available
The Mach-Zehnder electro-optic modulator (MZM) was designed and fabricated using the AFM COMSOL program and the pulse laser deposition (PLD) technique. The PLD technique was used to deposit silicon, silicon oxide and LN thin film. Previously estimated optical properties of the prepared films were employed in the theoretical design of the modulator....
Article
Full-text available
In this paper, the performance of wavelength division multiplexing based on free space optical communication is enhanced via the power comparative system (PCS). The proposed system is simulated by OptiSystem 7 and investigated under three main conditions, namely, without missig–pointing losses (MPL), with MPL and with MPL and PCS. In addition, thre...
Preprint
Full-text available
The simulation and investigation of a 32×10 Gb/s WDM all–optical bidirectional hybrid communication system for outdoor applications is presented in this article via multidisciplinary softwares. In order to track the system condition, a strain sensor based on fiber Bragg grating (FBG) is integrated in–line with the fiber optic link (FO–link). Then,...
Article
Full-text available
In this paper, a tattoo removal Q switching Nd: YAG laser, with a 6 nanosecond pulse duration, 2000 mJ power, frequency of pulses of 5 Hz was used to deposit of layer by layer of Silicone oxide, pure silicone, and lithium niobate for fabricated an optical modulator. The deposited layer by layer samples were analysed and characterized using the (XRD...
Article
Full-text available
In this paper, the design parameters of the wavelength division multiplexing based on free–space optical (WDM–FSO) within the C+L band are optimized via Opti-system 7 computer software. The performance of the proposed system is evaluated under different weather conditions, namely, clear, haze, rain, and fog. The Amounts of 1E-9 and 6 were adopted a...
Preprint
Full-text available
A Mach-Zehnder electro-optic modulator (EOM) was fabricated employing pulsed laser deposition (PLD) method. Lithium Niobate (LN) was bonded to silicon nanocrystal substrate such that a waveguide combined structures were obtained. The over-all Properties of prepared device were investigated. The formation of LN was ensured by the x-ray diffraction r...
Article
Full-text available
In this paper, the fiber optic cascade based on multimode interference (MMI) is demonstrated and investigated via COMSOL Multiphysics software. Two different cascades were adopted in this work, namely, single mode–multimode–single mode (SMS) and single mode–No–Core–single mode fiber (SNS). The transmission spectrum tuning range depending on the geo...
Article
Full-text available
In this paper, the performance of multiwavelength free space optical (MFSO) communication system is enhanced via optimization of the transceiver design parameters. The performance of the proposed system is investigated and compared with the previous work under the same weather condition, as well as with and without misalignment losses (ML). The opt...
Article
Full-text available
In this work, a wideband serial hybrid fiber amplifier based on second order stimulated Raman scattering (SO-SRS) is demonstrated. The optimum pumping power for Raman fiber amplifier with SO-SRS, is determined for six different Raman gain medium lengths. A wide flat gain bandwidth is achieved within the short, conventional and long band (S + C + L...
Conference Paper
This paper represents an overview of most articles which concerned with the nanophotonic lithium niobate film based on optical modulator. The previous published works are discussed and summarized as well the basic concept and the performance parameters of this type of optical modulators are explained. A lithium niobate film based on optical modulat...
Article
Full-text available
In this paper the effect of the environmental parameters, namely, dusts, water drops and dusty water drops on the performance of the photovoltaic (PV) panel have been experimentally investigated. The measurements have been conducted in the laboratory (indoor) apart the orientation angle of the solar panel and at a temperature of 30P 0 P C,. In this...
Article
Full-text available
This work presents a new approach to determine the maximum allowable pump power that causes fractures in solid-state lasers. By considering temperature-dependent-thermal conductivity, heat equation was solved and an analytical thermal model of laser diode double end-pumped cylindrical laser rod was deduced. Taking into account two unequal pump radi...
Article
Full-text available
In this paper, a simulation analysis of 40 Gb/s wavelength division multiplexing system of 32 channels is implemented through RZ modulation format by using a different hybrid fiber amplifier (HFA) configurations, namely, serial HFA, parallel HFA, and combined serial–parallel hybrid fiber amplifier (CSP-HFA). The performance of the proposed amplifie...
Conference Paper
In this paper, wideband serial hybrid fiber amplifier is simulated utilizing higher order stimulated Raman scattering (SRS). The amplifier structure is consisting of 3 m erbium doped fiber and 7 km of dispersion compensating fiber (DCF) as gain medium for an erbium doped fiber amplifier (EDFA) and Raman fiber amplifier (RFA), respectively. The prop...
Article
Full-text available
Optical wireless is the alternative approach to complete the deployment of optical cable networks in case of failure in implementation. In optical wave the attenuation due to atmospheric turbulence conditions causes a performance degradation of a free space optical (FSO) system. Thus, it will lead to the deterioration of the signal power in the opt...
Article
This work demonstrates the simulation of two different types of optical fiber amplifiers (OFA) utilizing OptiSystem–10, namely, 3 m length of erbium doped fiber amplifier (EDFA) and 7 km length of Raman fiber amplifier (RFA). The counter-pumped architecture is adopted for both proposed optical amplifiers. The optimum pump power (OPP) for each ampli...
Article
Full-text available
This work uses simulation software OptiGrating and OptiSystem to present the apodization effect on the performance of Fiber Bragg Grating (FBG) that is based on a strain–temperature sensor. Two FBGs with different center frequencies were designed via OptiGrating and then exported to OptiSystem to examine the impact of different apodization profiles...
Article
Full-text available
In this work, the thermal effect on the mirror reflectivity based on distributed Bragg reflector (DBR) in terms of the center wavelength shifting and reflectivity ratio is theoretically investigated and experimentally validated. The temperature of the proposed device was varied between the range of 300K to 400K in steps of 20K. According to the res...
Article
Full-text available
This work demonstrates the simulation of two different types of optical fiber amplifiers (OFA) utilizing OptiSystem-10, namely, 3 m length of erbium doped fiber amplifier (EDFA) and 7 km length of Raman fiber amplifier (RFA). The counter-pumped architecture is adopted for both proposed optical amplifiers. The optimum pump power (OPP) for each ampli...
Article
Full-text available
In this paper, the optimum pump conditions are determined for C+L band combined serial-parallel hybrid fiber amplifier (CSP-HFA), utilizing gain control technique via OptiSystem 7.0. The optimization includes determining the optimum pump power (OPP), the optimum pump wavelength (OPW) and optimum coupling ratio (OCR), within the longest 3– dB flat g...
Article
In this paper a combined serial–parallel hybrid fiber amplifier (SP–HFA) in the C+L–band is investigated and simulated via OptiSystem 7. The gain spectra of the C+L–band are flattened by optimizing the coupling ratio of the input signal power. The gain bandwidth of 62.5 nm from 1530 nm –to– 1592.5 nm within the gain variation of about 2.68 dB is ac...
Conference Paper
Full-text available
In this paper a tunable filter based on fiber Bragg grating (TF-FBG) utilizing a thermal technique is theoretically investigated and experimentally validated. According to the results, a tuning range is achieved about 0.6 nm in C-band region. While, for L-band region the wavelength shift is slightly greater than in the C-band region about0.7 nm. Th...
Article
Full-text available
Determine the optical properties of biological tissue is an important issue in medical applications. These optical properties are absorption coefficient (), scattering coefficient () and anisotropy factor (). There are many theoretical methods to measure tissue optical properties. These theoretical methods can be applied by knowing number of experi...
Article
Full-text available
In this work, a numerical analysis based on finite element method (FEM) has been used to predict both the temperature distribution and focal length in CW Nd:YAG laser rod. The double end-pumped utilizing two different pumping profiles, namely, Gaussian and super- Gaussian beam profiles are adopted in this simulation. In addition, four different su...
Article
Full-text available
In this paper a wideband tunable filter based on fiber Bragg grating (TF-FBG) utilizing tensile/ compression technique is theoretically investigated. According to the results, a wide tuning range is achieved about 48.36 nm in C-band region from 1513.7 nm to 1562.1 nm; 12.09 nm for tension and 36.27 nm for compression (C-band refers to the wavelengt...
Article
In this work, the effects of two apodization functions on the performance of two dispersion compensators, namely, linear and quadratic chirps, based on chirped fiber Bragg grating (CFBG), are investigated and simulated. The hyperbolic tangent function (Tanh) represents the first profile, which is used directly from OptiSystem 13, while the second f...
Article
In this study, a simulation analysis of 40-Gb/s long-haul (120 km) dense wavelength-division multiplexer system (DWDM) of 32 channels with 50 GHz spacing is conducted for duobinary return-to-zero modulation formats. Pre- and post-dispersion compensation schemes utilizing dispersion compensating fiber (DCF) and fiber Bragg grating (FBG) are analyzed...
Article
Full-text available
The performance of a discrete L‫ــ‬band Raman fiber amplifier (RFA) is investigated and compared for two different configurations: single and double‫ــ‬pass utilizing OptiSystem-10. The comparison between these two types of RFA under same input design parameters is done. By varying Raman pump power from 50 to 600 mW both amplifiers provide about 12...
Article
Full-text available
A finite-element method (FEM) was used to simulate numerically the effect of thermal lensing in YAG rods doped with Nd ion using LASCAD software. The temperature distribution and thermal lensing focal length of the composite laser rod (YAG/Nd:YAG) with one undoped end cap was considered and compared with conventional laser rod (Nd:YAG) by applyin...
Article
A finite-element method (FEM) was used to simulate numerically the effect of thermal lensing in YAG rods doped with Nd ion using LASCAD software. The temperature distribution and thermal lensing focal length of the composite laser rod (YAG/Nd:YAG) with one undoped end cap was considered and compared with conventional laser rod (Nd:YAG) by applying...
Article
Full-text available
This study demonstrates simulation and experimental validation of a wideband serial hybrid Raman/erbium-doped fiber amplifier. Two configurations are adopted; in type A, a Raman amplifier is the first stage, and in type B, an erbium-doped fiber amplifier is the first stage. At low input signal power, the average gain level is 20 dB with a flat gain...
Article
Full-text available
We demonstrate a simulation of a parallel hybrid fiber amplifier in the C+L-band with a gain controlling technique. A variable optical coupler is used to control the input signal power for both EDFA and RFA branches. The gain spectra of the C+L-band are flattened by optimizing the coupling ratio of the input signal power. In order to enhance the pu...
Conference Paper
A simple L-band multiwavelength Brillouin-Erbium fiber laser (MBEFL) that utilizes a passive erbium doped fiber (PEDF) at two different locations within the linear cavity was successfully demonstrated. The impact of the inclusion of such PEDF sections on the number of the generated Stokes lines, laser tunability and the laser cavity threshold are e...
Article
We demonstrate a simple design to enhance the performance of a multiwavelength Brillouin–Raman fiber laser by capturing the residual Raman pump power (RPP) from the laser cavity using a wavelength-selective coupler. The performance parameters of the laser system are investigated and compared with the conventional design under the same input design...
Article
A tunable multi-wavelength L-band Brillouin–Raman fiber laser with a 20-GHz channel spacing utilizing bidirectional ring cavity is proposed and experimentally investigated. The laser employs a co-pumped dispersion compensating fiber as a gain medium for both Brillouin and Raman gains. With a Raman pump of 425 mW, the laser system can generate up to...
Article
Full-text available
An erbium doped fiber amplifier in the conventional communication window utilizing single and double pump pass configurations were demonstrated and compared using OptiSystem 12 software. Both of gain level and gain profile were improved in double-pass configuration utilizing broadband optical mirror. The maximum gain in both single and double- pass...
Conference Paper
Full-text available
We experimentally demonstrate the impact of a section of passive Erbium doped fiber (EDF) within linear cavity multiwavelength Brillouin Erbium fiber Laser (MBEFL). The influence of such passive EDF section length on the tuning range and the lasing cavity threshold is experimentally presented. The lasing threshold of the MBEFL in case of without an...
Conference Paper
Two tunable multiwavelength Brillouin-Raman fiber lasers in the long-band region utilizing both linear and ring cavities were compared. The effect of Raman pump power on the performance parameters of the two cavities was investigated. At 10 dBm Brillouin pump power, up to 41 single spacing channels were obtained in the linear cavity, compared with...
Conference Paper
The effect of the location of the Erbium-doped fiber (EDF) on the performance of the hybrid dispersion compensation of Raman/EDF amplifier is discussed in this study. Two different configuration set-ups were determined according to the position of the EDF amplifier. The setup in which EDF A is positioned before is denoted by type A, while type B de...
Article
Full-text available
In this work, results are presented for a continuous wave diode laser single-end-pumped Nd:YVO 4 laser with maximum output power of 240mW in the TEM 00 mode at an optical pump power of 850mW. The laser performance under different output couplers has been studied both analytically and experimentally. The theoretical analysis provides a good predicti...
Article
Full-text available
The effect of a bidirectional recycling residual pump on the Brillouin Stokes signal threshold, as well as on its power, is experimentally investigated. The laser cavity is formed with two optical mirrors as the resonator reflectors which allow bidirectional residual pump recycling that causes bidirectional Brillouin gains. These gains significantl...
Article
Full-text available
We experimentally investigate the performance of L-band multiwavelength Brillouin-Raman fiber laser (MBRFL) under forward and backward pumped environments utilizing a linear cavity. A short length of 1.18 km dispersion compensating fiber is used as a nonlinear gain medium for both Brillouin and Raman gain. Experimental results indicate that the gai...
Article
Full-text available
In this article, an accurate model of multi-wavelength Brillouin fiber laser is developed by analytically solving cascade-stimulated Brillouin scattering equations in a linear cavity. The dependence of Stokes signal power on the incident pump power and the successive reflected transmitted powers is calculated. Furthermore, an analytical approach th...
Conference Paper
Full-text available
In this paper, the effect of the large signal power on the Raman amplification is simulated utilizing OptiSystem. Two types of Raman amplification systems are simulated; average power Raman amplifier model (APA-RFA) and bidirectional-fiber Raman amplifier model (Bi-Fiber RFA). A comparison is made between these two kinds of amplifiers under the sam...
Conference Paper
Full-text available
We experimentally investigates the effect of uni-directional and bi-directional cavity structure on the performance of the Brillouin fiber laser for the first and the second Stokes signals. The laser cavities; unidirectional and bidirectional are tested under the same experimental conditions using different SMF lengths. We observed that in both cav...
Conference Paper
Full-text available
We report experimental results demonstrating the stimulated Brillouin scattering threshold (SBSTH) features in multiwavelength Brillouin-Raman fiber laser against Raman pump power (RPP) variation. The reduction of SBSTH is attributed to the Raman amplification on each of oscillated Brillouin pump power (OBP) and generated Stokes signals. The satura...
Article
Full-text available
Background: Today, the processes of teeth bleaching by utilizing oxidation chemical components became a public and important as a cosmetically operative. Particularly the demanding on these processes increased with the developing in bleaching techniques, where laser light is used as catalyzer agent to increasing the efficiency and speed of these pr...
Article
Full-text available
The coupling tolerances is considered as an important parameters for the optical designer and it can not be ignored. Since the coupling efficiency is affected by the displacement of the optical components during the thermal expansion and the assembling processes, so, the coupling tolerances are just as important as coupling efficiency in the assess...
Article
Full-text available
The coupling tolerances is considered as an important parameters for the optical designer and it can not be ignored. Since the coupling efficiency is affected by the displacement of the optical components during the thermal expansion and the assembling processes, so, the coupling tolerances are just as important as coupling efficiency in the assess...