Spider veins are a common aesthetic problem mainly in females , the conventional method of treatment is by microsclerotherapy (injections) but laser therapy has become increasingly efficacious and a convenient method for treatment. The present study was performed to investigate the effectiveness and safety of pulsed diode laser (810nm) by doing thermal photocoagulation. Ten patients with lower limbs spider veins were included in this prospective study. They were treated with a repetitive pulsed diode laser in non contact technique using the following laser parameters (wave length 810nm,power 1 W ,pulse duration 0.1 s., pulse interval 0.5 s, spot diameter 4mm ,power density 7.9 W/cm2). Laser therapy was performed on day zero and day fourt

The main goal of this in vivo study was to evaluate the effect of 532nm Q-switched Nd: YAG Laser in combination with Human Serum Albumin 20% concentration (as a welding aid) on the liver tissue repair clinically, and histologically. The animals used in this study were 21 male rabbits divided into three main groups: control group (3 rabbits), conventionally treated group (9 rabbits) and Laser treated group (9 rabbits). Each two main groups (conventional and laser treated) consist of three sub-groups depending on the response evaluation at three different periods. The Laser group was treated using 532nm Q-switched Nd: YAG laser after adding human serum albumin immediately on the incised liver’s tissue. The energy of was 460mJ, and 4Hz fr

The efficiency of Nd:YAG laser radiation in removing debris and smear layer from prepared root
canal walls was studied. Fifty-seven human extracted single rooted anterior teeth were divided into three
groups. A group that was not lased is considered as a control group. The remaining teeth were exposed to
different laser parameters regarding laser energy, repetition rate and exposure time. For the case of the set of
parameters of 7 mJ laser energy, the cleaning was maximum at 3 p.p.s. repetition rate for 3 seconds exposure
time for, the coronal, middle and apical thirds. Above and below this energy level, there was an overdose
(melting) or under dose (no effect). Nevertheless for 10mJ laser energy case, the cleaning effi

Joining tissue is a growing problem in surgery with the advancement of the technology and more precise and difficult surgeries are done. Tissue welding using laser is a promising technique that might help in more advancement of the surgical practice. Objectives: To study the ability of laser in joining tissues and the optimum parameters for yielding good welding of tissues. Methods: An in-vitro study, done at the Institute of Laser, Baghdad University during the period from October 2008 to February 2009. Diode and Nd-YAG lasers were applied, using different sessions, on sheep small intestine with or without solder to obtain welding of a 2-mm length full thickness incision. Different powers and energies were used to get maximum effect. Re

This paper presents the effect of relativistic and ponderomotive nonlinearity on cross-focusing of two intense laser beams in a collisionless and unmagnetized plasma. It should be noted here that while considering the self-focusing due to relativistic electron mass variation, the electron ponderomotive density depression in the channel may also be important. Therefore/these two nonlinearties may simultaneously affect the self-focusing process. These nonlinearities depend not only on the intensity of one laser but also on the second laser. Therefore, one laser beam affects the dynamics of the second beam and hence the process of cross-focusing takes place. The electric field amplitude of the excited electron plasma wave (EPW) has been cal

Acne scars are one of the most common problems following acne vulgaris. Despite the extensive list of available treatment modalities, their effectiveness depends upon the nature of the scar. Ablative lasers had been used to treat acne scars; one of them is the fractional CO2 laser. The aim of this study is to evaluate the outcome of fractional CO2 laser in the treatment of acne scars. Methods: Since January 2010 to June 2013, using 10600 nm fractional CO2 laser beams, the acne scar of 400 patients, 188 males and 212 females, mean age of 34 years, have been treated and classified according to severity into four grades following Goodman and Baron classification. Each patient underwent 3-5 sessions once monthly. The mean laser exposure time

This study aims to evaluate the feasibility of using pulsed Nd:YAG laser spot welding to join dissimilar metals consisting of nickel and nickel-plated copper in busbar joints for lithium-ion batteries. The effects of key operating parameters, namely laser energy, pulse repetition rate, and focal position, on the mechanical and structural properties of the weld were examined. The results showed that an energy of 13 joules achieved the highest peak shear force of approximately 273 N with a homogeneous melt zone and limited surface defects, while an energy of 10 joules recorded the highest hardness value (370HV0.300) due to the balance between energy input and cooling rate. It was also found that a repetition rate of 20 Hz and a focal posit

Dental caries (tooth decay) is one of the most prevalent infectious disease and although of multifactorial origin, Streptococcus mutans is considered the principal pathogen in its development (i.e. bacterial processes damage hard tooth structure (enamel, dentine and cementum), producing dental cavities (holes in the teeth). The bactericidal properties of the Nd:YAG laser has been researched analyzing its use in caries prevention and bacterial reduction. One hundred twenty five samples were collected from carious teeth and isolated bacteria were diagnosed using microscopic examination, culture, biochemical tests, and Api 20 strep system. The results of this study showed that a noticeable decrease in the viability of Streptococcus mutans w

The Er, Cr: YSGG laser has emerged as a promising tool for safe and precise bone ablation in dental and maxillofacial procedures. This ex vivo study aimed to optimize the laser parameters to achieve efficient bone cutting with minimal thermal side effects.
Method: This ex vivo study aimed to evaluate the histological effects of varying ER, Cr: YSGG laser parameters on bone incision quality. Mandibular bone samples were collected from three freshly slaughtered sheep and sectioned into six blocks. Osteotomies were performed using an ER, Cr: YSGG laser (2780 nm, Waterlase iPlus) at six different power-frequency combinations (2.5W/20Hz, 4W/20Hz, 6W/20Hz, 4W/30Hz, 6W/30Hz, and 8W/30Hz). Each specimen was irradiated in contact mode for 25

The nonlinear refractive index and the nonlinear absorption coefficient of unmodified and functional poly(methyl methacrylate) PMMA films were studied before and after the addition of the filler by the z-scan technique, using a Q-switched Nd:YAG laser at two wavelengths: 532 nm and 1064 nm, and at three input energies (13, 33 and 53) mJ. Both linear and nonlinear refractive indices and absorption coefficients of polymer films were studied by using UV-VIS spectrophotometer. The results show that the creation of functional PMMA from unmodified PMMA will increase the nonlinear optical properties in the functional PMMA/copper matrix more than in the unmodified PMMA/copper matrix. Hence, the functional PMMA appears promising as a useful third

The purpose of this study is to demonstrate a simple high sensitivity vapor sensor for propanol ((CH3)2CHOH). A free space gap was employed in two arms of a Mach-Zehnder interferometer to serve as the sensing mechanism by adding propanol volume (0.2, 0.4, 0.6, 0.8, and 1) ml and to set the phase reference with a physical spacing of (0.5, 1, 1.5, and 2) mm. The propagation constant of transmitted light in the Mach-Zehnder interferometer’s gap changes due to the small variation in the refractive index inside sensing arm that will further shift the optical phase of the signal. Experimental results indicated that the highest sensitivity of propanol was about 0.0275 nm/ml in different liquid volume while highest phase shift was 0.182×103 i

The aim of the study was to evaluate the efficacy of diode laser (λ=940 nm) in the management of gingival hyperpigmentation compared to the conventional bur method. Materials and methods: Eighteen patients with gingival hyperpigmentation were selected for the study with an age between 12-37 years old. The site of treatment was the upper gingiva using diode laser for the right half and the conventional method for the left half. All patients were re-evaluated after the following intervals: 3 days, 7 days, 1 month and 6 months post-operation. Pain and functions were re-evaluated in each visit for a period of 1 day, 3 days and 1 week post-operation. Laser parameters included 1.5 W in continuous mode with an initiated tip (400 μm) placed in

الهدف: الهدف من البحث الحالي هو كشف الأنياب المنطمرة في الشدق العلوي باستخدام ل يزر الدايود ) 810 + 980 ( نانومتر) في مقارنة الأنياب المنطمرة حنكي ا اعتماد ا على هذه العوامل الألم، الورم، زمن الشفاء(. المقدمة: يوفر ليزر الصمام الثنائي( 810 + 980) اختراق ا عميق ا للأنسجة الرخوة وتخثر الدم وتجلط الدم بشكل ممتاز ولديه الحد الأدنى من التفاعل مع أنسجة الأسنان الصلبة .
المواد والطرق: جميع المرضى الذين يعا

Abstract: Background: Optical biosensors offer excellent properties and methods for detecting bacteria when compared to traditional analytical techniques.  It allows direct detection of many biological and chemical materials.  Bacteria are found in the human body naturally non-pathogenic and pathologically, as they are found in other living organisms.  One of these bacteria is Escherichia coli (E. coli) which are found in the human body in its natural and pathogenic form. E.coli bacteria cause many diseases, including Stomach, intestines, urinary system infections, and others. The aim of this study: is sensing and differentiation between normal flora and pathogenic E.coli. Material and method:

تطوير مستشعر لقياس التغير في معامل الانكسار للمحيط باستخدام تقنية مستشعر الألياف غير النواة على شكل حرف (D) .يتكون هذا المستشعر من قطعة من الألياف غير النواة ) CF ( ملحومة بين ليفين أحادي النمط ) SMF (. تم تلميع منتصف طول الألياف غير النواة باستخدام عجلة طحن لتقليل القطر من جانب واحد، مما أدى إلى إنشاء مقطع عرضي على شكل حرف D .تم اختبار أداء مستشعر DSCF باستخدام تركيزات مختلفة من محاليل كلوريد الصوديوم ( NaCl)، حيث تتراوح

Focusing of Gaussian laser beam through nonlinear media can induce spatial self- phase modulation which forms a far field intensity pattern of concentric rings. The nonlinear refractive index change of material depends on the number of pattern rings. In this paper, a formation of tunable nonlinear refractive index change of hybrid functionalized carbon nanotubes/silver nanoparticles acetone suspensions (F-MWCNTs/Ag-NPs) at weight mixing ratio of 1:3 and volume fraction of 6x10-6 , 9x10-6 , and 18x10-6 using laser beam at wavelength of 473nm was investigated experimentally. The results showed that tunable nonlinear refractive indices were obtained and increasing of incident laser power density led to increase the nonlinear refractive inde

Random laser gain media is synthesized with different types of dye at the same concentration (1×10^-3 M) as an active material and silicon dioxide NPs (silica SiO₂) as scatter centers through the Sol-Gel technique. The prepared samples are tested with UV–Vis spectroscopy, Fluorescence Spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Diffraction (EDX). The end result demonstrates that doped dyes with silica nanoparticles at a concentration of 0.0016 mol/ml have lower absorbance and higher fluorescence spectra than pure dyes. FESEM scans revealed that the morphology of nanocrystalline silica is clusters of nano-sized spherical particles in the range (25-67) nm. It is con

Fiber Bragg Grating has many advantages where it can be used as a temperature sensor, pressure sensor or even as a refractive index sensor. Designing each of this fiber Bragg grating sensors should include some requirements. Fiber Bragg grating refractive index sensor is a very important application. In order to increase the sensing ability of fiber Bragg gratings, many methods were followed. In our proposed work, the fiber Bragg grating was written in a D-shaped optical fiber by using a phase mask method with KrFexcimer. The resultant fiber Bragg grating has a high reflectivity 99.99% with a Bragg wavelength of 1551.2 nm as a best result obtained from a phase mask with a grating period of 1057 nm. In this work it was found that the rota

The purpose of this study is to investigate the biostimulation effect of 532 nm CW laser on the metabolism of Saccharomyces cerevisiae yeast. Cells were irradiated by 532 nm Nd:YAG laser using 0.153 W/cm2 power density at 30, 45, 60,180 and 300 seconds exposure times in their respective orders. Intrafluorescence parameters were measured by detection the autofluorescence intensity, proliferation rate and Imaging the fluorescent mitochondria using confocal laser scanning microscope. The results showed that the 30 and 45 second exposure times seem to have stimulated changes in the cells that led to increase proliferation, viability and mitochondrial activity. Autofluorescence of cells increased after 45 and 60 seconds exposure time. After 3

A characteristic study of a passively Q-switched diode pumped solid state laser system is presented in this work. For laser a comparison study for the theoretically calculated results with a simulation results using a software which calculates the Q-switched solid state laser parameters was such as energy, peak power and pulse width were performed. There was a good agreement between our theoretical calculations and the simulation values.

الخلفية: الورم الليفي العصبي الضفري [PN] هو ورم غير خبيث يؤثر على غمد الأعصاب الطرفية ويرتبط مع الورم الليفي العصبي من النوع 1 [NF1.1]. وقد ظهر العلاج بالليزر كنهج فعال محتمل لإدارة الأورام الليفية العصبية الضليعية الفموية، مما يجعلها أداة تشخيصية قيمة في مجال طب الأسنان.

عرض دراسة حالة: مريض ذكر، يبلغ من العمر 60 عامًا، تم تشخيصه بالإصابة بالورم الليفي العصبي من النوع الاول، أظهر تورمًا غير م

توفر طرق طبة المسحوق, بما في ذلك الصهر بالليزر الانتقائي و تنوعا كثيرا في كل من عمليات التصميم والتصنيع. ومع ذلك , فأن القيد الحالي لهذه الطريقة يكمن في قدرتها على انتاج أجزاء من مادة واحدة. بالنسبو لمتطلبات المواد المتعددة المعقدة مثل عمليات الطلاء. تتضمن الحلول المثالية تكاملا مخصصا للمواد المتنوعة المطلوبة للتحكم في عملية الذوبان والتصلب داخل واجهة المعادن المختلفة. في هذه الدراسة, تم أنشاء نموذج ديناميك

الهدف : الأسباب الأكثر شيوعا في فشل ارتباط الوتد الليفي هو الترميم الغيركافي والازاحه. التركيب السطحي للوتد الليفي يتأثر
بواسطة إشعاع الليزر وقد يعزز من قوة التصاقه. في هذه الدراسة الاستطلاعية نناقش تأثيرليزر Er,YAG وليزر Er,CR:YSGG على سطح الوتد الليفي وقوة التصاقه بالاسمنت الراتنجي في الأسنان المعالجة لبيا .
الطرق : تم بحث شامل في مقالات محرك كوكل و PubMed و Medline و Web of Science نشرت من 2013 إلى
2023 و

In this paper, tunable optical band-pass filters based on Polarization Maintaining Fiber –Mach Zehnder Interferometer presented. Tunability of the band-pass filter implemented by applying different mechanical forces N on the micro-cavities splicing regions (MCSRs). The micro-cavity formed by using three variable-lengths of single-mode polarization-maintaining fiber with (8, 16, 24) cm lengths, splice between two segments of (SMF-28) with (26, 13) cm lengths, using the fusion splicing technique.  Ellipsoidal shape micro-cavities experimentally achieved parallel to the propagation axis having dimensions between (12-24) μm of width and   (4-12) μm of length. A micro-cavity with width and length as high as 24 μm and 12 μ

تستقصي هذه الدراسة العوامل الحاسمة التي تؤثر على عمليات التنظيف بواسطة الليزر، مع التركيز الأساسي على السطوح المصنوعة من الألومنيوم 6061. يظهر قوة الليزر كعامل محوري، حيث تزيد مستويات القوة العالية من تفاعل الليزر مع المادة، مما يؤدي إلى إزالة لطبقات الأكسيد. تم التعرف على ظروف التنظيف الأمثل، بما في ذلك معاملات مثل 30% من القوة، وقيمة الخطوة 0.003، وسرعة 150 ملم/ث، وقطر شعاع ليزر يبلغ 200 ميكرومتر. وعلاوة على ذلك، ت

Laser assisted skin wound closure offers many distinct advantages over conventional closure
techniques. The objective of this in vitro experimental study, carried out at the Institute of Laser for
Postgraduate Studies/Baghdad University, was to determine the effectiveness of 980 nm diode laser in
welding of human skin wounds. Multiple 3-4 cm long full thickness incisions in a specimen of human
skin obtained from the discarded panniculus of an Abdominoplasty operation were tried to be laser
welded using a 4 mm spot diameter laser beam from a 980 nm diode laser at different laser parameters
and modes of action. The tensile strength at the weld site was analyzed experimentally. Although laser
assisted wound welding did

The aim of this study is to investigate the ability of malachite green (MG) combined with 650nm diode laser to kill Candida albicans and to spectrally study the MG photodegradation after photodynamic therapy (PDT) spectrally. Cultures of Candida albicans were exposed to 40mW, 650 nm diode laser in the absence of MG. In PDT group, the MG was added to the Candida suspension for 5 min then exposed to diode laser for (5, 10, 15, 20) min at power density of 0.59W/cm2. The absorption spectrum of the photosensitized fungal suspension was obtained. The data were submitted to T-test (p<0.05). A 650nm diode laser in the presence of MG reduced the number of CFU/ml in 98.4%. Laser with 650nm alone and MG alone did not reduce significantly the num

The present study was conducted with a view to determine whether focal laser therapy result in visual recovery and regression of macular edema in patients with non proliferative diabetic retinopathy and maculopathy ,and whether combined focal and scatter laser therapy in patients with proliferative diabetic retinopathy and maculopathy results in visual recovery ,regression of macular edema and regression of the risk factors. In the present work, a frequency doubled Nd: YAG laser was used for the treatment of diabetic retinopathy. The study evaluates 41 eyes of 33 diabetic patients both with Insulin Dependent Diabetes Mellitus IDDM, (n=16) and Non Insulin Dependent Diabetes Mellitus NIDDM, (n=17) with diabetic retinopathy divided into two

Background: This vitro study investigated the effectiveness of Er,Cr:YSGG laser-activated irrigation in removing root canal filling remnants during endodontic retreatment. The technique used photon-induced photoacoustic streaming (PIPS) at 700 μs pulse duration to activate 2.5% sodium hypochlorite (NaOCl) and 17% EDTA. Materials and methods: Twenty-one extracted human maxillary and mandibular premolars with single roots were instrumented and obturated using gutta-percha and a bioceramic root canal sealer. After retreatment using nickel-titanium rotary files (XP-endo Retreatment), the specimens were randomly assigned into three groups (n=7 per group) according to the irrigation

Laser diode with 980 nm has many attractive applications in telecommunication and photonic systems especially when it used for pumping the Erbium–Doped Fiber Amplifiers (EDFAs) which is an essential c- band amplifier that used in many applications for enhancing the nonlinear system conversion efficiency. In this work pulsed laser diode was manufactured after electronically implement the divider circuit with thermal stability of 14 pin 980 nm butterfly laser diode (AGREE SL 90S31A) that has maximum power of 160 mW. This driver circuit was based on the LM317 adjustable current regulator. The electronically chopped 980 nm laser diode achieved stable modulation in the frequency range from 1 Hz to 1 kHz. The proposed driver circuit is simpl