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Article
Study The effect of central ion to the dithene complexes on spectral shifting of saturable absorber band
دراسة تأثير الايون المركزي لمعقدات الدايثين على الزحزحة الطيفية لحزمة أمتصاص التشبع

Authors: Morooj.A.Abood مروج علي عبود --- Afrah.A.jaber افراح عبدالحسين جبر --- Ashwaq .A.jabor أشواق عبدالحسين جبر
Journal: Baghdad Science Journal مجلة بغداد للعلوم ISSN: 20788665 24117986 Year: 2011 Volume: 8 Issue: 2عدد خاص بمؤتمر الفيزياء Pages: 465-472
Publisher: Baghdad University جامعة بغداد

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Abstract

In this work dithine complexes prepared from dithiol benzil ligand and central ion to the Ni,Pd,Pt, element the ligand and complexes have been investigated using FTIR spectrophotometer and uv-vis-NIR spectral reigns show higher intensity represents the π-π* transition in the chromopher cycle .These absorption which appear in visible and near IR spectral regions ,According to the complexes of one group ,the spectral shifting due to the change of central ion has been found to be related to atomic number of central ion .This shifting is increased while decreasing the central ion atom number These complexes have been implemented in Nd+2:YAG cavity because each posses resonant absorption band near Nd+2:YAG, Nd+2:Glass emitting at (1060nm). pulse duration measured to complexes dissolved in dioxin(2*10-3M) is very short compared with free running pulse duration ,therefore the complexes work as Q-switch to the NIR lasers.

حضرت معقدات الدايثين لليكاند الدايثول بنزيل وايون مركزي لعناصر Ni,Pd,Pt ثم شخصت المعقدات المحضرة بمطياف FTIR ومطياف uv-Vis-NIR حيث أ ظهرت حزمة امتصاص بشدة عالية والتي تعود إلى الأنتقال الالكتروني (*)للمجموعة الكروموفورية والتي تمثل حزمة امتصاص تشبع حيث ظهرت عند المنطقة الطيفية المرئية والقريبة من الحمراء .عند مقارنة الزحزحة الطيفية لحزمة امتصاص التشبع للمعقدات وجد أنها تتجه نحو الأطوال الموجية الأقصر مع زيادة العدد الذري للايون المركزي . ونظرا لامتلاك الصبغات المحضرة حزم امتصاص تشبع عند المنطقة القريبة من (1060nm) والتي تمثل حزمة انبعاث لليزر Nd+2:YAGو Nd+2:Glassضمنت الصبغات داخل تجويف منظومة ليزر Nd+2:YAGوأجريت قياسات لحساب أمد النبضة للصبغات مذابة بدايوكسان وبتركيزM) 2*10-3) وتم الحصول على نبضة ليزرية بأمد قصير مقارنة بألتشغيل الحر وبذالك عملت هذه الصبغات كمفتاح عامل نوعية لليزرات القريبة من الحمراء.


Article
Manufacturing of flash lamp and studying its properties
تصنيع المصباح الوميضي ودراسة خصائصه

Authors: Yassin H. Mahmood ياسين حميد محمود --- Awatif S.Jassim عواطف صابر جاسم
Journal: Baghdad Science Journal مجلة بغداد للعلوم ISSN: 20788665 24117986 Year: 2010 Volume: 7 Issue: 2 Pages: 963-968
Publisher: Baghdad University جامعة بغداد

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Abstract

This study presents the design of flash-lamps for pumped solid-state lasers. In this research have been study some of characters for flash lamp. The optimum pressure operation is found using different flash lamps about (600-4000) mbar. In conclusion, it was shown that the increase in pressure due to improve efficiency of radiation and decrease of temperature. Also this study illustrated the reason of decrease temperature is atomic number and due to increase of radiation efficiency.

تم في هذا البحث تصنيع مصابيح وميضية لأغراض الضخ الليزري لليزرات الحالة الصلبة , وتم دراسة بعض الخصائص الخاصة بالمصباح الوميضي المصمم في هذه الدراسة. وجد من خلال القياسات العمليةوجد أن أفضل تشغيل لهذه المصابيح عند ضغط mbar) 4000 600-). تم التوصل كذلك أن زيادة الضغط يعمل على تحسين كفاءة الأشعاع وتقليل الحرارة ، كما أظهرت الدراسة أنه بتقليل العدد الذري تقل درجة الحرارة وتزداد الأشعاعية.


Article
Calculations of Long Pulsed Lasers for Lithotripsy

Author: Murooj N. Mohammad Ali
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 1 Pages: 72-81
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Urinary stone fragmentation with long pulsed Ho:YAG laser (wave lengthequal 2.1 μm) and Er:YAG laser (wave length equal 2.94 μm) investigated in thispaper.Fragmentation efficiency of these two lasers is measured by using various energysettings. Laser induced crater depth and ablation volume for both lasers wereexamined and compared using mathematical model. Theoretical results werecompared with experimental results obtained by Hyun Wook Kang.The study shows that the theoretical results and experimental results arecomparable, and the crater depth when using Er:YAG laser was more than that onHo:YAG laser.


Article
EFFECT OF INJECTION CURRENT ON SOME STATIC CHARACHTRISTICS OF QUARTERLY WAVELENGTH-SHIFTED DISTRIBUTED FEEDBACK LASER DIODES

Author: Mohammed D. Noori
Journal: Journal of Education for Pure Science مجلة التربية للعلوم الصرفة ISSN: 20736592 Year: 2012 Volume: 2 Issue: 1 Pages: 56-66
Publisher: Thi-Qar University جامعة ذي قار

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Abstract

Quarterly wavelength shifted (QWS) distributed feedback (DFB) laser structures are commonly referred to be associated with high mode selectivity, zero-frequency detuning and small threshold density. The present work shows the effect of the injection current on some static characteristics (photon density, carrier density , refractive index, gain margin and optical power) of QWS DFB laser diodes.


Article
Microcavity Length Role On The Characteristic Temperature And The Properties Of Quantum Dot Laser
دور طول التجويف المايكروي في درجة حرارة الخاصية و مميزات ليزر النقطة الكمية

Author: Ra'ed M. Hassan رائد محمد حسن
Journal: Journal of Basrah Researches (Sciences) مجلة ابحاث البصرة ( العلميات) ISSN: 18172695 Year: 2011 Volume: 37 Issue: 4A Pages: 44-55
Publisher: Basrah University جامعة البصرة

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Abstract

Quantum-dot laser devices contains microcavity length which initially populates the properties of quantum dot lasers (QDLs). We studied the influence upon the optical confinement layer free carriers density, confined carrier level occupancies in QDs, threshold current density, internal loss coefficient, characteristic temperature, the maximum operating temperature and QD lowest excitation energy. Our results have been calculated as functions of limit structure parameters of GaInAsP/InP QDL with wavelength of 1.55 μm. The QDL characteristic temperature was studied with the effective cross section and sets an upper limit certain temperature for operating temperature of a QD laser.

أجهزة ليزر النقطة الكمية (QD) تحتوي على طول التجويف المايكروي الذي هو أبتداءا يقوم بتأهيّل خصائص ليزرات النقطة الكمية (QDLs) . دراسنا هذا التأثير على كثافة الحاملات الحرة لطبقة الحجز البصري ، الإشغال مستوى الحامل المقيد في QDs ، وكثافة تيار العتبة ، معامل الخسارة الداخلية ، درجة الحرارة الخاصية ، درجة حرارة التشغيل القصوى و الطاقة التهيج أدنى للـ QD. حسبت نتائجنا كدالة لبرامترات تركيب محددة للـ QDL نوع GaInAsP /InP عند الطول الموجي 1.55 ميكرومتر. كما درست درجة الحرارة خصائص QDL مع المقطع العرضي الفعال ومجموعات لحدود أعلى من درجة حرارة المؤكدة لدرجات حرارة التشغيل ليزر QD.


Article
Characterization of Quantum Well Diode Pumped Nd:YVO4 Using V-Shape Technique

Authors: A.J. Haider --- H.M. Hikmet
Journal: Iraqi Journal of Applied Physics Letters الرسائل العراقية في الفيزياء التطبيقية ISSN: 1999656X Year: 2008 Volume: 1 Issue: 1 Pages: 31-34
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

V-shape face pumping scheme was used, a comparison between the bulkand the QW laser was made when used as pumping sources in CW mode toa Nd:YVO4 disk crystal, the output power obtained for the bulk diode laserwas 29mW, and when using the QW diode laser the maximum outputpower obtained was 58mW. In pulsed mode when using internallytriggered bulk diode laser with prf=1.3kHz, the maximum emitted peakpower was found to be 40mW, with a resonator length L=13cm, while forexternal triggering with prf=3Hz, the maximum output peak power wasfound to be 145mW.


Article
Effect of Self-Absorption on the Output Power of CW CO2 Laser

Authors: O.A. Hamadi --- D.N. Raouf --- N.A.K. Alrubaiey
Journal: Iraqi Journal of Applied Physics Letters الرسائل العراقية في الفيزياء التطبيقية ISSN: 1999656X Year: 2009 Volume: 2 Issue: 1 Pages: 31-34
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 work, the effect of self-absorption by molecules of the active medium on the output laser power of a low-pressure CW CO2 laser was studied. The effects of discharge current, output coupling and total gas pressure on the output laser power were discussed. It was explained that the self-absorption depends on CO2 concentration, output coupling and discharge current and there is a threshold value for both output coupling and discharge current at which the absorption is clearly effective.


Article
Key Mechanisms of The Nonlinear Amplification: Physics and Applications

Authors: M. Adaams --- D. Davis --- M. Tatcham --- M. Fishner
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2005 Volume: 1 Issue: 2 Pages: 3-11
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

This review discusses the physical mechanisms of absorptive and dispersive nonlinearity in amplifiers resulting from interband and intraband electron transitions, with as assessment of the relative strengths and response times of these nonlinearities. Where appropriate, the potential applications of these nonlinearities in optical networks are also indicated.


Article
Characterization of Diode Laser-Pumped Nd:YVO4 Disk Laser

Authors: A.J. Haider --- K.I. Hajem --- M.K. Zaher
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2008 Volume: 4 Issue: 2 Pages: 31-34
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 work describe experimental set up disk laser of Nd:YVO4 in active mirror configuration, face pumping and cooling by thermoelectric Cooler (TEC) type heat exchanger to over come the limitation of prior design. With (4x5x1mm) disk dimensions to investigate the relationship between the pumping power from a diode laser at (808nm) with the optical elements in the setup and with the output power. The results show that a (0-600)mW CW output power which indicate 56% efficiency at (1064nm) wavelength from Nd:YVO4 thin disk material when pumped with power between (0-1500) mW from a 808nm CW laser diode.


Article
(3-5) μm and (8-12) μm Wavelengths Ultra-Short Tunable Laser Pulses Using Optical Parametric Oscillation Technique

Authors: A.A. Al- Dergazly --- F.F. Rasheed --- S.M. Jumaa
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2008 Volume: 4 Issue: 4 Pages: 35-39
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

A computational investigation has been carried out on optical parametric oscillation (OPO) technique. Non-collinear phase matching between the pumping wave and the two generated signal and idler waves has been taken into consideration. In order to separate the two generated waves a design has been put forward for a resonator for each wave within the same cavity and interrelated by mirror that transmits the pumped laser beam. The cavity configuration takes into account the three types of phase matching between the three waves. Solid state lasers were considered for pumping the nonlinear crystal. Furthermore, attention has been paid on the solid state Er:YAG laser for pumping the positive uniaxial AgGaSe2 crystal to generate a signal wave of (8-12)μm wavelength so the generated idler wave from 3.82 to 4.55μm wavelength.

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