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Article
New Glasses for Optical Fibres and Their Applications (invited contribution)

Author: D.N. Payne
Journal: Iraqi Journal of Applied Physics Letters الرسائل العراقية في الفيزياء التطبيقية ISSN: 1999656X Year: 2009 Volume: 2 Issue: 4 Pages: 19-20
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

Glasses with high-refractive index, high acousto-optic merit, low phonon energy and good solubility of the rare-earth are essential for optical waveguides devices of the future. At the ORC, research on advanced materials for multifunction waveguides is driven by device requirements. A more efficient optical fibre amplifier for 1.3um requires new glasses of lower vibrational energies to minimise nonradiative decay. Planar lossless splitters rely on a new waveguide material which allows highincorporation of erbium. Modulators need bulk or fibre optics which interact with acousto-optic power. Other new glasses with very high photosensitivity are being developed for fibre Bragg gratings, and highly non-linear glasses for all-optical switches. It is clear that for functions as diverse as amplification, splitting, modulation, switching or filtering the key to these devices is new glass materials.


Article
Low Loss in a Gas Filled Hollow Core Photonic crystal fiber
خسائر قليلة في الليف البلوري الفوتوني ذي قلب المجوف المملوء بالغاز

Author: Hanan J. Taher حنان جعفر طاهر
Journal: Baghdad Science Journal مجلة بغداد للعلوم ISSN: 20788665 24117986 Year: 2010 Volume: 7 Issue: عدد خاص بمؤتمر العلمي النسوي 1 Pages: 129-138
Publisher: Baghdad University جامعة بغداد

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Abstract

The work in this paper focuses on the experimental confirming of the losses in photonic crystal fibers (PCF) on the transmission of Q-switched Nd:YAG laser. First HC-PCF was evacuated to 0.1 mbar then the microstructure fiber (PCF) was filled with He gas & gas. Second the input power and output power of Q-switched Nd:YAG laser was measured in hollow core photonic bandgap fiber (HCPCF). In this work loss was calculated in the hollow core photonic crystal fiber (HCPCF) filled with air then N2, and He gases respectively. It has bean observed that the minimum loss obtained in case of filling (HC-PCF) with He gas and its equal to 15.070 dB/km at operating wavelength (1040-1090) nm.

يركز العمل على أثبات وبطريقة عملية الخسائر في الألياف البلورية الفوتونية لنقل ليزر الندميوم-ياك ذو عامل النوعية Q.أولاً الليف البلوري الفوتوني ذي القلب المجوف يفرغ من الهواء الى 0.1 ملي بار ثم يملئ بغاز الهليوم وبعدها بغاز النايتروجين الليف الصغير التركيب (PCF). ثانياً تم قياس القدرة الداخلة والقدرة الخارجة لليزر الندميوم-ياك ذو عامل النوعية Q خلال الليف البلوري الفوتوني ذي القلب المجوف, في هذا العمل الخسائر حسبت في الليف البلوري الفوتوني ذي القلب المجوف(HCPCF) المملؤ بالهواء وبعدها بغاز الهليوم ثم بغاز النايتروجين تم ملاحظة أقل خسائر مستحصلة في حالة مليء الليف البلوري الفوتوني ذي القلب المجوف بغاز الهليوم وتساوي dB/km 15.070 عند الطول الموجي (1040-1090) نانومتر.


Article
Phase Noise Compensation for Coherent Orthogonal Frequency Division Multiplexing in Optical Fiber Communications Systems

Author: J.K. Hmood
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2009 Volume: 5 Issue: 2 Pages: 3-10
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this paper, the Coherent Optical (CO) systems using Orthogonal Frequency Division Multiplexing (OFDM) for dispersion compensation is demonstrated. The Quadrature Amplitude Modulation QAM-OFDM transmitter signal was controlled by the Mach-Zender Modulator (MZM) which modulates the laser source with wavelength of 1550nm. The heterodyne receiver with dual-polarization optoelectronic down-converter is used to obtain good coherent detection without using optical phase locked loop. The analytical part was done using a software simulator. All the proposed system components were simulated using VPIphotonic simulation software for testing CO-OFDM system. The transmitted signal, optical spectrum, eye diagram and constellation diagram was obtained to evaluate system performance.


Article
Compensation of Phase Noise for Coherent Frequency Division Multiplexing in Optical Fiber Communications System

Author: Jasim K.H.
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2013 Volume: 9 Issue: 2 Pages: 3-10
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this paper, the Coherent Optical (CO) systems using Orthogonal Frequency Division Multiplexing (OFDM) for dispersion compensation is demonstrated. The Quadrature Amplitude Modulation QAM-OFDM transmitter signal was controlled by the Mach-Zender Modulator (MZM) which modulates the laser source with wavelength of 1550nm. The heterodyne receiver with dual-polarization optoelectronic down-converter is used to obtain good coherent detection without using optical phase locked loop. The analytical part was done using a software simulator. All the proposed system components were simulated using VPIphotonic simulation software for testing CO-OFDM system. The transmitted signal, optical spectrum, eye diagram and constellation diagram was obtained to evaluate system performance.


Article
Study For Soliton propagation in Optical Fibers

Authors: Abbas I.O. --- hamed I. Aboud
Journal: Basic Education College Magazine For Educational and Humanities Sciences مجلة كلية التربية الأساسية للعلوم التربوية والإنسانية ISSN: 23043717 23128003 Year: 2012 Issue: Special Pages: 190-201
Publisher: Babylon University جامعة بابل

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Abstract

One of the keys to the success of the ensuing photonics revolution will be the use of optical solitons in fiber optic communication systems, solitons are a special breed of optical pulses that can propagate through an optical fiber undistorted for tens of thousands of kilometers. The soliton phenomenon was first described by John Scott Russell (1808-1882) who observed a solitary wave in the Union Canal in Scotland. He reproduced the phenomenon in a wave tank and named it the "Wave of Translation". The key to soliton formation is the careful balance of the opposing forces of chromatic dispersion and self-phase modulation.


Article
Theoretical Treatment to Determine the Quality of Photonic Crystal Fiber (PCF) as a Function of the Number of Air Holes

Authors: R.M. Taha --- F.A. Sabah
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2013 Volume: 9 Issue: 3 Pages: 31-35
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this paper, the design of photonic crystal fiber (PCF) depending on the number of holes and rings is presented. Three different types of PCF will be assumed. The effect of increasing number of holes was explained using the relations between chromatic dispersion (Dc), loss, bit error rate (BER) and pitch (ᴧ) for wavelength interval 1-2µm and three fiber lengths (50, 100 and 200 km). These relations were plotted using MATLAB-2008 software. The obtained results showed that the 3rd PCF with the highest number of holes has provided better quality than the other two types of PCF.


Article
Theoretical Treatment to Determine the Quality of Photonic Crystal Fiber (PCF) as a Function of the Number of Air Holes

Authors: Rana M. Taha --- Fayroz A. Sabah
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2016 Volume: 12 Issue: 2 Pages: 31-35
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this paper, the design of photonic crystal fiber (PCF) depending on the number of holes and rings is presented. Three different types of PCF will be assumed. The effect of increasing number of holes was explained using the relations between chromatic dispersion (Dc), loss, bit error rate (BER) and pitch (ᴧ) for wavelength interval 1-2μm and three fiber lengths (50, 100 and 200 km). These relations were plotted using MATLAB-2008 software. The obtained results showed that the 3rd PCF with the highest number of holes has provided better quality than the other two types of PCF.


Article
Comparing Study To Design Optical Fiber From Doped Silica For Different Application
د ا رسة مقارنة لتصميم الياف بصرية من السميكا المطعمة لمتطبيقات المختمفة

Author: Mohammed Abdullah Husein محمد عبدالله حسين
Journal: kirkuk university journal for scientific studies مجلة جامعة كركوك - الدراسات العلمية ISSN: 19920849 / 26166801 Year: 2013 Volume: 8 Issue: 2
Publisher: Kirkuk University جامعة كركوك

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Abstract

The purpose of this research is to design optical fibers which can be used for different of practical applications and study its characteristics :critical angle ,numerical aperture .normalized frequency ,number modes ,effective area .which are all function of wavelength .fixing the cladding material which has the smaller refractive index and varying the core material which has a larger refraction index ,three types of doped material was chosen : 16.9 m/o Na2O+32.5 m/o B2O3+50.6 m/o SiO2 ,7.9 m/o GeO2+92.1 m/o SiO2 ,1.0 m/o F+99.0 m/o SiO2and calculating the refractive index as function of wavelength using selimer equation and by a proper choice of the core and clad materials ,two type of optical fibers were designed .considering the communication windows ,the first fiber has core material of : 16.9 m/o Na2O+32.5 m/o B2O3+50.6 m/o SiO2 and a clad of 1.0 m/o F+99.0 m/o SiO2as receiving fiber clad to its large numerical aperture and the second fiber has a core material of 7.9 m/o GeO2+92.1 m/o SiO2and cladding material of 1.0 m/o F+99.0 m/o SiO2this can be used as transmitting fiber due to its small numerical aperture

الهدف من ث ا البحث ثو تصميم الياف بصرية للارم توايفها مة ادستخدامات العممية المختمفة ود ا رسة خواصها التالية:ال ا زوية الحرجة ،الفتحة العددية ،التردد العيار ،عدد ادنماط ،المساحة الفعالة وجميعها دالة لمطول الموجة ،وبت بيت ماداللالاف ات معامل ادنكسار ادصلار وتلايير ماد الم ات معامل ادنكسار ادكبر مقد تم اختيار لا ة انوا من مواد السميكاالمطعمة : 16.9 m/o Na2O+32.5 m/o B2O3+50.6 m/o SiO2 ,7.9 m/o GeO2+92.1 m/o SiO2 ,1.0 m/o F+99.0 m/o SiO2 وحسا معامل ادنكسار دالة لمطول الموجة باستخدام معادلة سيممير، وباختيار مناس لمادتةالقم واللالاف تم تصميم نوعين من الميف البصر بادخ بنلار ادعتبار نوام ادتصادت مان الميف ادول القم ل من ماد16.9 m/o Na2O+32.5 m/o B2O3+50.6 m/o SiO2 واللالاف من ماد 1.0 m/o F+99.0 m/o SiO2يستخدم كميف استقبال لكبر الفتحة العددية ل اما الميف ال انة القم ل من ماد 7.9 m/o GeO2+92.1 m/o SiO2واللالاف من ماد 1.0 m/o F+99.0 m/o يمكن استخدام كميف ارسال لصلار الفتحة العددية ل .

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