scholarly journals A Modified Approach for the Blumlein-line Laser Power Calculations: Electrical and Optical Power Waveforms

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Mohamed Otman Twati ◽  
Abubaker B. Otman
Keyword(s):  
Laser Power ◽  
Laser System ◽  
Optical Power ◽  
Theoretical Work ◽  
Electrical Circuit ◽  
Nitrogen Laser ◽  
Power Calculations ◽  
Decoupling Approach ◽  
Laser Systems ◽  
Blumlein Line

In this paper, a modified approach for output power calculations of the nitrogen laser system is reported. The power calculations is based on the distributed parameter model of the Blumlein-line circuit along with the decoupling approach of the laser rate equation from the electrical circuit equations. The general laser power assumption is considered in calculating the output optical power. The effect of the laser gap inductance on both the electrical and optical power waveforms is simulated and discussed. The theoretical work presented here is quite general and could be applied to many other fast discharges laser systems, such as CO2 and copper vapor lasers.

scholarly journals Human Dental Enamel and Dentin Structural Effects after Er:yag Laser Irradiation

2014 ◽  
Vol 15 (3) ◽  
pp. 283-287 ◽  
Author(s):  
Mateus Rodrigues Tonetto ◽  
Marcelo Ferrarezi de Andrade ◽  
Shelon Cristina Souza Pinto ◽  
Darlon Martins Lima ◽  
José Roberto Cury Saad ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Soft Tissues ◽  
Er:Yag Laser ◽  
Laser System ◽  
Dental Enamel ◽  
Target Tissue ◽  
Structural Effects ◽  
Ablation Process ◽  
Dental Tissues ◽  
Laser Systems

ABSTRACT Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations — namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. Clinical relevance Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems. How to cite this article Lima DM, Tonetto MR, de Mendonça AAM, Elossais AA, Saad JRC, de Andrade MF, Pinto SCS, Bandéca MC. Human Dental Enamel and Dentin Structural Effects after Er:yag Laser Irradiation. J Contemp Dent Pract 2014;15(3):283-287.

Innovations in Excimer Laser Refractive Technology – Focus on the WaveLight® EX500 Excimer Laser System

2010 ◽  
Vol 04 (01) ◽  
pp. 44
Author(s):  
Arthur Cummings ◽  
Keyword(s):  
Excimer Laser ◽  
Refractive Surgery ◽  
Laser System ◽  
Higher Order ◽  
Corneal Tissue ◽  
Night Time ◽  
Higher Order Aberrations ◽  
Operative Complications ◽  
Laser Systems ◽  
Technology Focus

Excimer laser refractive surgery aims to correct lower order eye aberrations such as myopia, astigmatism and hyperopia by altering the shape of the corneal curvature through the ablation of corneal tissue. Early excimer systems were associated with concerns over post-operative complications, such as night-time driving problems, glare and halos. Furthermore, it was difficult to prevent or treat higher-order aberrations with these early systems (and conventional refractive surgery procedures). Innovations in excimer laser technology have led to the introduction of excimer laser systems with enhanced features, such as high repetition rates and customised ablation profiles, improving the safety and effectiveness of this type of surgery and allowing a broad range of patients to be treated, including those with higher-order aberrations. This article discusses these innovations in excimer laser refractive technology, focusing on the clinical use of the recently introduced WaveLight® EX500 Excimer Laser system.

Nitrogen laser system for diagnosing z-pinch and x-pinch plasmas

1997 ◽  
Vol 68 (7) ◽  
pp. 2725-2729 ◽  
Author(s):  
Daniel H. Kalantar ◽  
David A. Hammer ◽  
Alan W. De Silva
Keyword(s):  
Laser System ◽  
Nitrogen Laser ◽  
Z Pinch

scholarly journals Size dependent efficiency of photophoretic swimmers

2015 ◽  
Vol 184 ◽  
pp. 381-391 ◽  
Author(s):  
Andreas P. Bregulla ◽  
Frank Cichos
Keyword(s):  
Particle Size ◽  
Laser Power ◽  
Symmetry Axis ◽  
Particle Surface ◽  
Finite Size ◽  
Optical Power ◽  
Surface Flow ◽  
Incident Laser ◽  
Size Dependent ◽  
Incident Laser Power

We investigate experimentally the efficiency of self-propelled photophoretic swimmers based on metal-coated polymer particles of different sizes. The metal hemisphere absorbs the incident laser power and converts its energy into heat, which dissipates into the environment. A phoretic surface flow arises from the temperature gradient along the particle surface and drives the particle parallel to its symmetry axis. Scaling the particle size from micro to nanometers, the efficiency of converting optical power into motion is expected to rise with the reciprocal size for ideal swimmers. However, due to the finite size of the metal cap, the efficiency of a real swimmer reveals a maximum depending sensitively on the details of the metal cap shape. We compare the experimental results to numerical simulations.

Third-order optical nonlinearity effect of DNA- and polyvinylpyrrolidone-functionalized carbon nanotubes

2015 ◽  
Vol 24 (01) ◽  
pp. 1550008 ◽  
Author(s):  
Liangmin Zhang ◽  
Benjamin Steckling ◽  
Adrian Lucero ◽  
Andreas Schmitt-Sody ◽  
William White ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Water Solution ◽  
Laser System ◽  
Optical Power ◽  
Optical Nonlinearity ◽  
Optical Absorption Coefficient ◽  
Third Order ◽  
Multiwalled Carbon ◽  
The Third ◽  
Optical Susceptibility

We have used single-stranded DNA (ssDNA) and polyvinylpyrrolidone (PVP) to disperse multiwalled carbon nanotubes (MWNTs) in water solution through sonication and centrifuge procedures. The advantage of these two polymers is that they do not need toxic organic solvents to distribute the carbon nanotubes. The scanning electron microscope (SEM) technique has been used to investigate the interaction between polymer molecules and MWNTs. The images show that MWNTs can be distributed effectively into the two polymer solutions. The third-order optical susceptibility, nonlinear optical absorption coefficient and optical power limiting of these dispersions have been characterized experimentally using a femtosecond laser system with a tunable range of 750–850 nm. The imaginary part of the third-order optical susceptibility has also been computed.

scholarly journals Clinical feasibility trial on 1940 nm Tm: fiber laser intervention of hyperplastic inferior nasal turbinates

2012 ◽  
Vol 1 (3) ◽  
Author(s):  
Ronald Sroka ◽  
Miriam Havel ◽  
Christian Betz ◽  
Thomas Kremser ◽  
Andreas Leunig
Keyword(s):  
Fiber Laser ◽  
Laser System ◽  
Operation Time ◽  
Endoscopic Examination ◽  
Feasibility Trial ◽  
Nasal Breathing ◽  
Contact Mode ◽  
Endoscopic Control ◽  
Validated Questionnaire ◽  
Laser Systems

AbstractA number of different laser systems have been used for volume reduction of hyperplastic nasal turbinates. In case of endonasal application, fiber-controlled diode lasers are preferred due to reasons of cost and practicability. The aim of this clinical feasibility study was to show the coagulative and tissue reducing effects using a novel Tm: fiber laser system emitting at λ=1940 nm.This clinical feasibility trial included 11 patients suffering from hyperplastic inferior nasal turbinates, who were therapy-refractory to conservative medical treatment. The obstructive nasal cavity was treated using the 1940 nm Tm: fiber laser at <5 W output power. The treatment was performed in non-contact mode under endoscopic control. Patients’ symptoms were documented both preoperatively and on days 1–3 and 28 postoperatively using a non-validated questionnaire. Additionally, an endoscopic examination was performed.None of the patients showed infections, and no hemorrhages or other complications occurred intra- or postoperatively. The mean laser activation time during the surgical procedure was extremely short being 28.0±8.5 s. In conjunction with a low power setting (median, 3 W; mean±standard deviation, 3.3±1.1 W), a low energy of 90.2±37.8 J was applied. A significant reduction in nasal obstruction could be documented in all patients on day 28 postoperatively. Evaluation, as assessed preoperatively and 4 weeks postoperatively, showed significant subjective improvements.The treatment of hyperplastic inferior turbinates using a 1940 nm Tm: fiber laser provides sufficient tissue reduction in a short operation time using low total energy. Patients described a significant improvement in nasal breathing postoperatively.

A Dynamic Model for Condition Monitoring of a High-Power CO2 Industrial Laser

1999 ◽  
Vol 121 (2) ◽  
pp. 157-164 ◽  
Author(s):  
J. F. Tu ◽  
J. G. Katter ◽  
L. E. Monacelli ◽  
M. Gartner
Keyword(s):  
Co2 Laser ◽  
Laser Cooling ◽  
High Power ◽  
Power Distribution ◽  
Cooling System ◽  
Laser System ◽  
Operating Conditions ◽  
Distribution Model ◽  
Dynamic Features ◽  
Laser Systems

Industrial laser systems handle high power consumptions and may function under undesirable operating conditions if the systems are not properly maintained. It is sometimes difficult to diagnose why a laser is not functioning properly because the optical output is the result of complex interactions among many parameters such as the total gas pressure, effectiveness of the laser cooling system, operating environment, and gradual deterioration of laser components. In this paper, a dynamic power distribution model is developed to characterize the power distribution of a high-power transverse-flow DC-excited CO2 laser to account for dynamic effects such as continuously ramping up and down the laser output power and the cyclic nature of the chiller. The model contains the essential dynamic features of a CO2 laser system and yields solutions sufficiently accurate for practical diagnostic purposes.

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