The variation of mass ablation rate with laser wavelength and target geometry

1982 ◽  
Vol 42 (1) ◽  
pp. 55-59 ◽  
Author(s):  
T.J. Goldsack ◽  
J.D. Kilkenny ◽  
B.J. MacGowan ◽  
S.A. Veats ◽  
P.F. Cunningham ◽  
...  
Keyword(s):  
Ablation Rate ◽  
Laser Wavelength

Measurements of Ablation Pressure and Mass Ablation Rate Using a Target Pendulum and a Thin Foil Target at 10 µm Laser Wavelength

1983 ◽  
Vol 22 (Part 2, No. 4) ◽  
pp. L248-L250 ◽  
Author(s):  
Hiroyuki Daido ◽  
Ryuzi Tateyama ◽  
Kazuki Ogura ◽  
Kunioki Mima ◽  
Sadao Nakai ◽  
...  
Keyword(s):  
Thin Foil ◽  
Ablation Rate ◽  
Laser Wavelength ◽  
Foil Target ◽  
Ablation Pressure

Laser-wavelength dependence of mass-ablation rate and heat-flux inhibition in laser-produced plasmas

1982 ◽  
Vol 26 (4) ◽  
pp. 2289-2292 ◽  
Author(s):  
R. Fabbro ◽  
E. Fabre ◽  
F. Amiranoff ◽  
C. Garban-Labaune ◽  
J. Virmont ◽  
...  
Keyword(s):  
Heat Flux ◽  
Wavelength Dependence ◽  
Ablation Rate ◽  
Laser Wavelength

scholarly journals Scanning electron microscope studies on laser ablation of solids

2019 ◽  
Vol 37 (01) ◽  
pp. 101-109 ◽  
Author(s):  
Mohamed E. Shaheen ◽  
Joel E. Gagnon ◽  
Brian J. Fryer
Keyword(s):  
Pulse Width ◽  
Laser Energy ◽  
Laser System ◽  
Picosecond Laser ◽  
Laser Pulses ◽  
Ablation Rate ◽  
Laser Wavelength ◽  
High Laser Fluence ◽  
Electron Imaging ◽  
Scanning Electron

AbstractThis study investigates the interaction of picosecond laser pulses with sapphire and brass in air using scanning electron microscopy. A picosecond laser system operating at a wavelength of 785 nm, pulse width of 110 ps, and variable repetition rate (1–1000 Hz) was used in this study. The pulse width applied in this work was not widely investigated as it lies in the gap between ultrashort (femtosecond) and long (nanosecond) pulse width lasers. Different surface morphologies were identified using secondary electron and backscattered electron imaging of the ablated material. Thermal ablation effects were more dominant in brass than in sapphire. Exfoliation and fractures of sapphire were observed at high laser fluence. Compared with brass, multiple laser pulses were necessary to initiate ablation in sapphire due to its poor absorption to the incident laser wavelength. Ablation rate of sapphire was lower than that of brass due to the dissipation of a portion of the laser energy due to heating and fracturing of the surface.

scholarly journals Measurements and laser-wavelength dependence of mass-ablation rate and ablation pressure in planar layered targets

1991 ◽  
Vol 9 (3) ◽  
pp. 769-778 ◽  
Author(s):  
F. Dahmani ◽  
T. Kerdja
Keyword(s):  
Steady State ◽  
Energy Transport ◽  
Laser Light ◽  
Plasma Heating ◽  
Wavelength Dependence ◽  
Ablation Rate ◽  
Laser Wavelength ◽  
Ablation Pressure ◽  
Hydrodynamical Simulations ◽  
Laser Flux

Layered-targets experiments at 1.06-μm laser light have been performed in order to measure mass-ablation rate ṁ and ablation pressure Pa as a function of absorbed laser flux Ia and laser wavelength λL at irradiances of 1011-4.5 × 1012 W/cm2. The results can be put in the forms ṁ(g/cm2-s) ≈ 4.25 × 105[Ia(W/cm2)/1014]5/9(1 μm/λL)4/9 and Pa(Mbar) ≈ 20[Ia(W/cm2)/1014]7/9(1 μm/λL)2/9, which are consistent with the estimates obtained from a steady-state self-regulated model for plasma heating and with hydrodynamical simulations. Results show also a small lateral energy transport.

Holmium: Yag Laser Angioplasty

1992 ◽  
Vol 33 (6) ◽  
pp. 538-541 ◽  
Author(s):  
S. H. Duda ◽  
M. Wehrmann ◽  
K. K. Haase ◽  
P. E. Huppert ◽  
K. R. Karsch ◽  
...  
Keyword(s):  
Laser Beam ◽  
Optical Fibers ◽  
Ablation Rate ◽  
Laser Angioplasty ◽  
Laser Wavelength ◽  
Mid Infrared ◽  
Ho:Yag Laser ◽  
Infrared Wavelength ◽  
Calcified Plaque ◽  
Free Running

This experimental study was designed to define the potential value of a mid-infrared holmium laser in the free running mode for angioplasty. Immediately after removal, fresh normal and diseased human cadaveric arteries were irradiated under saline with a Ho:YAG laser (wavelength 2.13 μm). The laser was pulsed at 3 Hz, 250 μs pulse width and fluences of 10 to 40 J/cm2. The laser beam was coupled to ring catheters with multiple low-OH quartz fibers. The tip of the delivery device was held in direct contact with the vessel surface with the laser beam oriented perpendicularly. Ablation of atherosclerotic plaque was accomplished at an ablation threshold of 10 J/cm2. The ablation rate was 2.1 to 8.3 μm/pulse. Removal of calcified plaque was only partially effective. There were marked thermal effects with vacuolizations extending up to 1505 ± 178 μm into the adjacent tissue. Laser light at the mid-infrared wavelength of 2.13 μm is supposed to be attractive as it is readily absorbed in water and can easily be transmitted through optical fibers. However, Q-switching seems to be essential to minimize thermal side effects and to make effective ablation of calcium possible.

Surface Modification of Aluminum Nitride and of Aluminum by Excimer Laser

1992 ◽  
Vol 285 ◽  
Author(s):  
A.J. Pedraza ◽  
J.-Y. Zhang ◽  
H. Esrom
Keyword(s):  
Aluminum Nitride ◽  
Excimer Laser ◽  
Substrate Surface ◽  
Ablation Rate ◽  
Laser Wavelength ◽  
Mechanism Of Decomposition ◽  
Self Consistent ◽  
A New Technique ◽  
193 Nm ◽  
Evaporation Kinetics

ABSTRACTA new technique for selective metallization of aluminum nitride (AIN) has been previously reported (1). It involves the use of an excimer laser to activate the AIN surface followed by electroless plating (Cu,Ni,Au) of the irradiated areas. The mechanism of decomposition of ALN is accompanied by ablation and the formation of an Al film on the substrate surface. Ablation rates are reported here as a function of fluence and number of pulses for three different wavelengths λ = 193 nm (ArF), λ = 248 (KrF) and λ = 351 nm (XeF).The effect of laser wavelength on the ablation rate is discussed. The ablation rates for Al were zlso measured and are compared with the AIN ablation rates. A numerical thermal model is used to analyze the mechanisms of laser ablation of both materials. The evaporation kinetics are incorporated into the model. The Clausius-Clapeyron approximation is used to make a self-consistent calculation of boiling and decomposition temperatures.

EFFECT OF LASER WAVELENGTH AND ABLATION TIME ON PULSED LASER ABLATION SYNTHESIS OF AL NANOPARTICLES IN ETHANOL

2012 ◽  
Vol 05 ◽  
pp. 58-65 ◽  
Author(s):  
A. BALADI ◽  
R. SARRAF MAMOORY
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Ablation Rate ◽  
Laser Wavelength ◽  
Aluminum Nanoparticles ◽  
Ablation Efficiency ◽  
Ablation Time ◽  
Al Nanoparticles ◽  
Ablated Mass

Aluminum nanoparticles were synthesized by pulsed laser ablation of Al targets in ethanol for 5-15 minutes using the 1064 and 533 nm wavelengths of a Nd:YAG laser with energies of 280-320 mJ per pulse. It has been found that higher wavelength leads to significantly higher ablation efficiency, and finer spherical nanoparticles are also synthesized. Besides, it was obvious that higher ablation time resulted in higher ablated mass, while lower ablation rate was observed. Finer nanoparticles, moreover, are synthesized in higher ablation times.

scholarly journals The effect of laser wavelength on the ablation rate of carbon

2014 ◽  
Vol 117 (1) ◽  
pp. 395-400 ◽  
Author(s):  
J. Hoffman ◽  
J. Chrzanowska ◽  
S. Kucharski ◽  
T. Moscicki ◽  
I. N. Mihailescu ◽  
...  
Keyword(s):  
Ablation Rate ◽  
Laser Wavelength

Imaging nanostructures on ablated kapton polymide

1993 ◽  
Vol 51 ◽  
pp. 872-873
Author(s):  
Daniel L. Callahan ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Polymer Surface ◽  
Grating Period ◽  
Laser Wavelength ◽  
Integrated Devices ◽  
Transmission Electron ◽  
Excimer Laser Irradiation ◽  
Produce Line ◽  
Line Patterns ◽  
Anisotropic Conduction

Excimer laser irradiation has been used to interferometrically ablate submicron line patterns on to Kapton polyimide. Such patterned material may exhibit highly anisotropic conduction as was predicted from previous studies showing enhanced conductivity from uniformly ablated material. We are currently exploiting this phenomenon to create integrated devices using conventional polymers as both dielectrics and conductors. Extensive scanning electron microscopy (SEM) and limited transmission electron microscopy (TEM) have been conducted in order to characterize the morphology of such patterned nanostructures as a function of processing conditions.The ablation technique employed produces an interference pattern on the polymer surface of period equal to half that of a diffraction grating period, independent of the laser wavelength. In these experiments, a 328 nm grating has been used to produce line patterns of 164 nm line-spacings as shown in Figures 1 and 2. A 200 Å Au coating has been used to both prevent charging and, perhaps more importantly, enhance contrast.

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