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

This is prospective study began in Jan. 2003 and concluded in April 2004, was undertaken to examine the benefits of 810 nm diode laser in treatment of four patient with bilateral vocal cord paralysis also to compare the results with conventional treatment Material and methods: 810 nm diode laser 15 watts was used in these cases under general anesthesia, and induction of anesthetic drug done through tracheostomy tube in all patients. All patients were decanulated “Tracheostomy tube removed”, the voice of all preserved within normal. Laser surgery in this case has more benefit and advantage than conventional methods even if the patient need more than on session of laser operation because of high success rate, less complication and easy

The main purpose of this work is the construction of an optical parametric amplifier (OPA) to generate a 629 nm pulsed laser. KTP nonlinear crystals were used for both parametric oscillation and amplification. A singly resonant parametric oscillator (OPO) is constructed to generate a signal of 1.54 μm and idler of 3.4 μm when the OPO system is pumped by 1.064 μm Q – switched Nd: YAG laser. The signal was then mixed with the pumping beam in OPA system to form the wanted wavelength. The obtained optical conversion efficiency was 60%.

An assembled pulsed Nd:YAG laser-robot system for spot welding similar and dissimilar metals is presented in this paper. The study evaluates the performance of this system through investigating the possibility and accuracy of executing laser spot welding of 0.2 mm in thickness stainless steel grade AISI302 to 0.5 mm in thickness low carbon steel grade AISI1008. The influence of laser beam parameters (peak power, pulse energy, pulse duration, repetition rate, and focal plane position on the final gained best results are evaluated. Enhancement of the experimental results was carried by a computational simulation using ANSYS FLUENT 6.3 package code.

Femtosecond laser pulse propagation in monomode optical fibers is demonstrated and investigated numerically (by simulations) and experimentally in this paper. A passively mode locked Nd:glass laser giving a pulse duration of about 200 fsec at 1053 nm wavelength and 120 mW average optical power with 100 MHz repetition rate is used in the experimental work. Numerical simulations are done by solving the nonlinear Schrödinger equation with the aid of Matlab program. The results show that self phase modulation (SPM) leads to compression of the spectral width from 5 nm to 2.1 nm after propagation of different optical powers (34, 43, 86 and 120 mW) in fibers of different length (5, 15, 35 m). The varying optical powers produced a varying

The  present  study  was  conducted  with  a  view  to  determine

whether focal laser therapy results in avisual recovery and regression of macular odema in patients with non-proliferative diabetic maculopathy. A

Frequency doubled Nd:YAG laser was used for the treatment of diabetic maculopathy. For several has been studied and the treatment results were discussed. The study evaluates 14 eyes of 8 diabetic patients. Mathematical model of the laser interaction with the retinal tissue is demonstrated and analysis results are explained and compared with the recent experimental and mathematical models . It has been shown that the laser treatment of the retinal diabetic macolapathy ,

The present study was conducted on 20 patients suffering from different types of lesion like
pyogenic granuloma, peripheral giant cell granuloma, mucoceles, pregnancy tumour, Fordyce's granules
and irritating fibroma.The cases were selected from outpatient clinic of the Al Kydhemya Teaching
Hospital. Patients were treated by diode laser (810±20 nm) at the affected areas of the oral cavity with
continuous contact focused mode until excision of the lesion with coagulation of the oozing area after
excision. Patients were followed up after 2 days, 7 days and 2 weeks to assess healing process and any
post operative complication. Some of undiagnosed lesion sent for histopathological examination. No
serious complications w

The spectral characteristics and the nonlinear optical properties of the mixed donor (C-480) acceptor (Rh-6G) have been determined. The spectral characteristics are studied by recording their absorption and fluorescence spectra. The nonlinear optical properties were measured by z-scan technique, using Q-switched Nd: YAG laser with 1064 nm wavelength. The results showed that the optimum concentration of acceptor is responsible for increasing the absorption and the emission bandwidth of donor to full range and to 242 nm respectively by the energy transfer process, also the efficiency of the process was increased by increasing the donor and acceptor concentration. The obtained nonlinear properties results of the mixture C-480/ Rh-6G showed

The research is concerned about studying the absorption spectrum of the solution coumarin dye C47. The chloroform solvent was used with C47 dye in three different concentrations 10-4, 10-5 and 10-6 M. The laser dye solution was prepared by dissolving the required amount of dye in chloroform alcohol, while studying absorption spectrum before and after irradiation with gamma ray by cobalt-60 source 60Co at exposure time, which are 0, 4, 6 and 18 hours with different absorbed doses 0, 136, 204 and 612 Gy. The results show that red shift in the absorption spectrum was increased by increasing the concentration of laser dye solutions , while the increase of gamma dose led to increase the red shift after irradiation, as the exposure period and irr