نتایج جستجو برای: waveguide co2 laser

تعداد نتایج: 266457  

2005
V. N. Ochkin

An analysis is presented of the effect of the RF frequency on the active media of CO2 waveguide lasers. It is found that the characteristics are improved with increasing RF frequency because the space charge sheath width decreases with increasing excitation frequency. We also found that the sheath width decreases with the discharge current; this fact was never discussed before. The higher the e...

2013
W. Kam Y. S. Ong W. H. Lim R. Zakaria

We report on the ablation and fabrication of optical waveguide using allyl-diglycol CR39 polymer. Pulse nanosecond (ns) laser (248 nm KrF) and continuous wave (CW) (244 nm argon-ion) irradiation are performed to observe surface modification on the polymer and potentially utilize it for channel waveguide. The pulsed UV laser creates craters with different depth as fluence increases to quantify t...

پایان نامه :دانشگاه آزاد اسلامی واحد علوم پزشکی تهران - دانشکده پزشکی 1389

هدف: این مطالعه به منظور بررسی میزان اثربخشی fractional co2 laser در جوان سازی پوست انجام شده است. روش مطالعه: این مطالعه به صورت یک clinical case series انجام شده است و حجم نمونه مورد بررسی شامل 59 خانم بود که بطور متوالی از بین بیماران مراجعه کننده به کلینیک های پوست و لیزر در سطح شهر تهران در سال 1388 انتخاب شدند. یافته ها: درصد بهبودی در نخستین فالوآپ به طور میانگین 03/85 درصد با انحراف م...

Journal: :Nano letters 2012
Ren-Min Ma Xiaobo Yin Rupert F Oulton Volker J Sorger Xiang Zhang

With unprecedented ability to localize electromagnetic field in time and space, the nanometer scale laser promises exceptionally broad scientific and technological innovation. However, as the laser cavity becomes subwavelength, the diffraction of light prohibits the directional emission, so-called the directionality, one of the fundamental attributes of the laser. Here, we have demonstrated a d...

Journal: :Optics letters 1990
B D Robert J E Sipe

We consider a laser beam incident normally upon a waveguide with a Kerr nonlinearity. Although the laser is uniform in the plane of the waveguide, we show that the waveguide fields can be unstable to growth, forming coherent periodic structures. The initial, exponential time dependence is determined, and we find a steady-state solution. Finally, we note that the mechanism necessary for this ins...

Journal: :Optics letters 2013
John R Macdonald Stephen J Beecher Patrick A Berry Graeme Brown Kenneth L Schepler Ajoy K Kar

We report a Cr:ZnSe channel waveguide laser operating at 2486 nm. A maximum power output of 285 mW is achieved and slope efficiencies as high as 45% are demonstrated. Ultrafast laser inscription is used to fabricate the depressed cladding waveguide in a polycrystalline Cr:ZnSe sample. Waveguide structures are proposed as a compact and robust solution to the thermal lensing problem that has so f...

2009
Martin Ams Graham D. Marshall Peter Dekker James A. Piper Michael J. Withford

Direct-write optical waveguide device fabrication is probably the most widely studied application of femtosecond laser micromachining in transparent dielectrics at the present time. Devices such as buried waveguides, power splitters, couplers, gratings, optical amplifiers and laser oscillators have all been demonstrated. This paper reviews the application of the femtosecond laser direct-write t...

Journal: :Optics express 2005
Haroldo Hattori Christian Seassal Xavier Letartre Pedro Rojo-Romeo Jean Leclercq Pierre Viktorovitch Marc Zussy Lea di Cioccio Loubna El Melhaoui Jean-Marc Fedeli

In recent years, many groups have envisioned the possibility of integrating optical and electronic devices in a single chip. In this paper, we study the integration of a photonic crystal laser fabricated in InP with a silicon passive waveguide. The coupling of energy between a 2D photonic crystal (PhC) triangular lattice band-edge laser and waveguide positioned underneath is analyzed in this pa...

Journal: :journal of lasers in medical sciences 0
shahin kasraei dental research center, department of restorative dentistry, school of dentistry, hamadan university of medical sciences, hamadan, iran mohammad atefat department of restorative dentistry, school of dentistry, hamadan university of medical sciences, hamadan, iran maryam beheshti private practice, tehran, iran. nassimeh safavi laser application in medical sciences research center, shahid beheshti university of medical sciences, tehran, iran. maryam mojtahedi department of restorative dentistry, school of dentistry, hamadan university of medical sciences, hamadan, iran loghman rezaei-soufi dental research center, department of restorative dentistry, school of dentistry, hamadan university of medical sciences, hamadan, iran.

introduction: since it is not possible to form an adequate micromechanical bond between resin cement and zirconia ceramics using common surface treatment techniques, laser pretreatment has been suggested for zirconia ceramic surfaces. the aim of this study was to evaluate the effect of carbon dioxide (co 2 ) laser treatment on shear bond strength (sbs) of resin cement to zirconia ceramic. metho...

Journal: :journal of computational & applied research in mechanical engineering (jcarme) 2015
m. azizpour m. ghoreishi a. khorram

this paper was aimed to report the 3d finite element analysis simulation of laser welding process of ti6al4v 1.7 mm sheets in butt joint in order to predict the temperature distribution, hardness, and weld geometry. the butt-joint welds were made using co2 laser with the maximum power of 2.2 kw in the continuous wave mode. a part of the experimental work was carried out to verify the weld geome...

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