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Prospect of CW Raman Laser in Silicon- on- Insulator Nano-Waveguides
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Numerical analysis predicts that continuous-wave (CW) Raman lasing is possible in Silicon-On-insulator (SOI) nano-waveguides, despite of presence of free carrier absorption. The scope of this paper lies on lasers for communication systems around 1550 nm wavelength. Two types of waveguide structures Strip and Rib waveguides have been incorporated. The waveguide structures have designed to be 220 nm in height. Three different widths of (350, 450, 1000) nm were studied. The dependence of lasing of the SOI Raman laser on effective carrier lifetime was discussed, produced by tow photon absorption. At telecommunication wavelength of 1550 nm, Raman lasing threshold was calculated to be 1.7 mW in Rib SOI waveguide with dimensions width (W= 450 nm) and Length (L= 25 mm). The obtained Raman lasing is the lowest reported value at relatively high reflectivities. Raman laser in SOI nano-waveguides presents the important step towards integrated on-chip optoelectronic devices.
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Publication Date
Tue Jun 11 2002
Journal Name
Iraqi Journal Of Laser
Investigating the Effects of Carbon Dioxide Laser Fluence on Oral Soft Tissue
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This study investigates the surgical and thermal effects on oral soft tissues produced by CO2 laser emitting at 10.6 micrometers with three different fluences 490.79, 1226.99 and 1840.4 J/cm2. These effects are specifically; incision depth, incision width and the tissue damage width and depth. The results showed that increasing the fluence and /or the number of beam passes increase the average depths of ablation. Moreover, increasing the fluence and the number of beam passes increase the adjacent tissue damage in width and depth. Surgeons using CO2 laser should avoid multiple pulses of the laser beam over the same area, to avoid unintentional tissue damage.

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Publication Date
Mon Mar 13 2023
Journal Name
Diagnostics
The Effect of a Bioactive Oral System and CO2 Laser on Enamel Susceptibility to Acid Challenge
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This study evaluated the structural changes of enamel treated by the Regenerate system and carbon dioxide (CO2) laser against acid challenge. Thirty human enamel slabs were prepared and assigned into three groups: Group I: untreated (control); Group II: treated with the Regenerate system; and Group III exposed to CO2 laser. All specimens were subjected to an acid challenge (pH 4.5–7.0) for 14 days. Specimens were evaluated and compared at 120 points using five Raman microspectroscopic peaks; the phosphate vibrations ν1, ν2, ν3, and ν4 at 960, 433, 1029, and 579 cm−1, respectively, and the carbonate at 1070 cm−1, followed by Vickers microhardness test. The ratio of carbonate to phosphate was correlated to the equivalent mic

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Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Experimental Evidence of Chaotic Resonance in Semiconductor Laser
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In this paper, an experimental study has been conducted regarding the indication of resonance in chaotic semiconductor laser.  Resonant perturbations are effective for harnessing nonlinear oscillators for various applications such as inducing chaos and controlling chaos. Interesting results have been obtained regarding to the effect of the   chaotic resonance by adding the frequency on the systems. The frequency changes nonlinear dynamical system through a critical value, there is a transition from a periodic attractor to a strange attractor. The amplitude has a very relevant impact on the system, resulting in an optimal resonance response for appropriate values related to correlation time. The chaotic system becomes regular under

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Publication Date
Mon Aug 19 2024
Journal Name
Journal Of Ovonic Research
Synthesis of PPy- Nd2O3 nano-composite for utilization in supercapacitor applications
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In this study, chemical oxidation was employed for the synthesis of polypyrrole (PPy) nanofiber. Furthermore, PPy has been subjected to treatment using nanoparticles of neodymium oxide (Nd2O3), which were produced and added in a certain ratio. The inquiry centered on the structural characteristics of the blend of polypyrrole and neodymium oxide after their combination. The investigation utilises X-ray diffraction (XRD), FTIR, and Field Emission Scanning Electron Microscopy (FE-SEM) for PPy, 10%, 30%, and 50% by volume of Nd2O3. According to the electrochemical tests, it has been noted that the nanocomposites exhibit a substantial amount of pseudocapacitive activity.

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Publication Date
Sun Aug 01 2021
Journal Name
Laser Micro- And Nano-scale Processing
Physical principles of laser–material interaction regimes for laser machining processes
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Lasers, with their unique characteristics in terms of excellent beam quality, especially directionality and coherency, make them the solution that is key for many processes that require high precision. Lasers have good susceptibility to integrate with automated systems, which provides high flexibility to reach difficult zones. In addition, as a processing tool, a laser can be considered as a contact-free tool of precise tip that became attractive for high precision machining at the micro and nanoscales for different materials. All of the above advantages may be not enough unless the laser technician/engineer has enough knowledge about the mechanism of interaction between the laser light with the processed material. Several sequential phenom

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Publication Date
Wed Jan 15 2020
Journal Name
Iraqi Journal Of Laser
Electronically Implementation and Detection of Pulse Laser from Continuous Laser Diode
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This research aims to design a high-speed laser diode driver and photodetector, the result is the
design of the high-speed laser diode driver with a short pulse of 10 ns at 30 KHz frequency and the
delivered maximum pulse voltage is 5.5 mV. Also, its optical output power of the laser diode driver is
about 2.529 mW for the centroied wavelength 1546.7 nm with FWHM of 286 pm and (1270-1610) nm.
The design of the circuit based on bipolar transistor where the input pulse signal is simply generated by
an arduino kit with 15 kHz frequency and then compensated to trigger to small signal amplifier which
was is simply NPN C3355 transistor and the output is a current driver to the laser diode. OptiSystem
software and Electronic

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Publication Date
Sun Jan 01 2023
Journal Name
8th Engineering And 2nd International Conference For College Of Engineering – University Of Baghdad: Coec8-2021 Proceedings
Effect of permeation grouting with nano-materials on shear strength of sandy soil: An experimental study
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Publication Date
Thu Jan 07 2021
Journal Name
Indian Journal Of Forensic Medicine & Toxicology
Effect of Dentifrices with Different Abrasives on the Surface Roughness of a Nano Composite Resins materials
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Background: to evaluate the effect of different dentifrices on the surface roughness of two composite resins (nanofilled-based and nanoceramic – based composite resins). Materials and methods: Forty specimens (diameter 12 mm and height of 2mm) prepared from different composite resin materials: Z350 (nanofilled composite, and Ceram-X (nanoceramic) .they were subjected to brushing simulation equivalent to the period of 1 year. The groups assessed were a control group brushed with distilled water (G1), Opalescence whitening toothpasteR (G2), Colgate sensitive pro-relief (G3) and Biomed Charcoal Toothpaste (G4). The initial and final roughness of each group was tested by surface roughness tester. The results were statistically analyzed using

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Publication Date
Sun Dec 15 2019
Journal Name
Journal Of Baghdad College Of Dentistry
The Effects of Nano Alumina On Mechanical Properties of Room Temperature Vulcanized Maxillofacial Silicone (Pilot Study)
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Background: Facial disfigurement can be the result of a congenital anomaly, trauma or tumor surgery, in many cases the prosthetic rehabilitation is indicated. Maxillofacial prosthetic materials should have desirable and ideal physical, aesthetic, and biological properties and those properties should be kept for long period of time in order to reach patient acceptance. Silicone elastomer are the most commonly used material for facial restoration because of its favorable properties mechanically and physically as the biocompatibility and good elasticity. Aim of this study: This study aimed to evaluate the effect of addition of Aluminum oxide (Al2O3) Nano fillers in different concentrations on tear strength and hardness of VST 50F room tempe

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Publication Date
Fri Jun 01 2018
Journal Name
Journal Of Taibah University Medical Sciences
Effect of nano-titanium oxide addition on some mechanical properties of silicone elastomers for maxillofacial prostheses
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Objective This study evaluated the effects of adding titanium oxide (TiO2) nanofillers on the tear strength, tensile strength, elongation percentage, and hardness of room-temperature-vulcanized (RTV) VST50F and high-temperature-vulcanized (HTV) Cosmesil M511 maxillofacial silicone elastomers. Methods Two types of maxillofacial elastomers, VST50F RTV and Cosmesil M511 HTV, were used. Nano-TiO2 powder was applied as a nanofiller. A total of 120 specimens were fabricated, 60 each of VST50F and Cosmesil M511. The specimens of each type of elastomer were divided into three equal groups on which tests were conducted for tear strength, tensile strength, and hardness i.e., 20 specimens were used for each test. Each group of 20 specimens was further

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