Periodic Nanostructure on 65Mn Produced by Femtosecond Laser Irradiation

2010 ◽  
Vol 154-155 ◽  
pp. 490-493
Author(s):  
Dong Qing Yuan ◽  
Jian Ting Xu
Keyword(s):  
Femtosecond Laser ◽  
Laser Fluence ◽  
Pulse Length ◽  
Field Vector ◽  
Electric Polarization ◽  
Laser Wavelength ◽  
Femtosecond Laser Irradiation ◽  
Large Area ◽  
Periodic Microstructures ◽  
Processing Control

The periodic microstructures on 65Mn plate were induced by the irradiation of the femtosecond laser with the laser wavelength of 800 nm and the pulse length of 130 fs. The parallel periodic ripples structures were observed at the laser fluence of 1 J/cm2 with different pulses number( N=5,50,400,800) which lied parallel to the laser electric polarization field vector. For 400 pulses, the nano-holes arrays were generated to interrupt the consistent ripples structures.For 800 pulses, initial nano-holes evolution to the grooves, which the direction were uncertainly. Further experiments have been made to induce large area consitent ripple structures by scanning, at the laser fluence of 1 J/cm2 with speed v=500μm/s. 2D arrays were induced by accurate processing control

scholarly journals Uncertainty Analysis of Melting and Resolidification of Gold Film Irradiated by Nano- to Femtosecond Lasers Using Stochastic Method

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Nazia Afrin ◽  
Yuwen Zhang ◽  
J. K. Chen
Keyword(s):  
Femtosecond Laser ◽  
Laser Fluence ◽  
Gold Film ◽  
Control Volume ◽  
Coupling Factor ◽  
Femtosecond Laser Irradiation ◽  
Free Standing ◽  
Input Parameters ◽  
Lattice Coupling ◽  
Solid Liquid

A sample-based stochastic model is presented to investigate the effects of uncertainties of various input parameters, including laser fluence, laser pulse duration, thermal conductivity constants for electron, and electron–lattice coupling factor, on solid–liquid phase change of gold film under nano- to femtosecond laser irradiation. Rapid melting and resolidification of a free-standing gold film subject to nano- to femtosecond laser are simulated using a two-temperature model incorporated with the interfacial tracking method. The interfacial velocity and temperature are obtained by solving the energy equation in terms of volumetric enthalpy for control volume (CV). The convergence of variance (COV) is used to characterize the variability of the input parameters, and the interquartile range (IQR) is used to calculate the uncertainty of the output parameters. The IQR analysis shows that the laser fluence and the electron–lattice coupling factor have the strongest influences on the interfacial location, velocity, and temperatures.

scholarly journals Uncertainty Analysis of Melting and Resolidification of Gold Film Irradiated by Nano- to Femtosecond Lasers Using Stochastic Method

2016 ◽  
Author(s):  
Nazia Afrin ◽  
Yuwen Zhang ◽  
J. K. Chen
Keyword(s):  
Femtosecond Laser ◽  
Laser Fluence ◽  
Gold Film ◽  
Control Volume ◽  
Coupling Factor ◽  
Femtosecond Laser Irradiation ◽  
Free Standing ◽  
Input Parameters ◽  
Lattice Coupling ◽  
Solid Liquid

A sample-based stochastic model is presented to investigate the effects of uncertainties of various input parameters, including laser fluence, laser pulse duration, thermal conductivity constants for electron, and electron-lattice coupling factor, on solid-liquid phase change of gold film under nano- to femtosecond laser irradiation. Rapid melting and resolidification of a free standing gold film subject to nano- to femtosecond laser are simulated using a two-temperature model incorporated with the interfacial tracking method. The interfacial velocity and temperature are obtained by solving the energy equation in terms of volumetric enthalpy for control volume. The convergence of variance (COV) is used to characterize the variability of the input parameters, and the interquartile range (IQR) is used to calculate the uncertainty of the output parameters. The IQR analysis shows that the laser fluence and the electron-lattice coupling factor have the strongest influences on the interfacial location, velocity, and temperatures.

Biocompatibility of Titanium Dioxide Film Modified by Femtosecond Laser Irradiation

2014 ◽  
Vol 783-786 ◽  
pp. 1377-1382 ◽  
Author(s):  
Masahiro Tsukamoto ◽  
Togo Shinonaga ◽  
Akiko Nagai ◽  
Kimihiro Yamashita ◽  
Takao Hanawa ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Film Surface ◽  
Polarization Vector ◽  
Cell Spreading ◽  
Laser Wavelength ◽  
Femtosecond Laser Irradiation ◽  
Periodic Nanostructures ◽  
Cell Test

Titanium (Ti) is one of the most widely used for biomaterials, because of its excellent anti-corrosion and high mechanical properties. In addion to these properies, the bioactivity of Ti is required. Recently, coating of the titanium dioxide (TiO2) film on Ti plate surface is useful methods to obtain biocompatibility of Ti plate. If periodic nanostructures were formed on the film surface, direction of cell spreading might be controlled due to grooves direction. Then, femtosecond laser is one of the useful tools of periodic nanostructures formation. Peiriod of periodic nanostructures might be varied by changing the laser wavelength. In the experiments, the film was formed on Ti plate with an aerosol beam which was composed of submicron size TiO2 particles and helium gas. The film was irradiated with the femtosecond laser. Laser wavelengths of the laser was at 1044, 775 and 388 nm, respectively. Periodic nanostructures, lying perpendicular to the laser electric field polarization vector, were formed on the film by femtosecond laser irradiation at 1044, 775 and 388 nm, respectively. The period of the periodic nanostructures on the film produced by femtosecond laser irradiation at 1044, 775 and 388 nm was about 350, 230 and 130 nm, respectively. In the cell test, cell spreading along the grooves of the periodic nanostructures was observed although it was not done for the film without the periodic nanostructures. These results suggested that direction of cell spreading could be controlled by the periodic nanostructures formation

scholarly journals Femtosecond laser irradiation of molecular excitonic films for nanophotonic response control and large-area patterning

2019 ◽  
Vol 27 (13) ◽  
pp. 18044 ◽  
Author(s):  
Byung Hoon Woo ◽  
Yejin Son ◽  
Jiyeon Choi ◽  
Sangmin Chae ◽  
Hyo Jung Kim ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Femtosecond Laser Irradiation ◽  
Large Area ◽  
Response Control

Femtosecond Laser Ablation of Titanium and Silicon

2000 ◽  
Author(s):  
Mengqi Ye ◽  
Costas P. Grigoropoulos
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Laser Fluence ◽  
Laser System ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Femtosecond Laser Irradiation ◽  
Nanosecond Laser ◽  
Iccd Camera ◽  
Plume Emission

Abstract Femtosecond laser ablation of titanium and silicon samples has been studied via time-of-flight (TOF), emission spectroscopy and microscopy measurement. Laser pulses of around 100 fs (FWHM) at λ = 800 nm were delivered by a Ti:sapphire femtosecond laser system. A vacuum chamber with a base pressure of 10−7 torr was built for ion TOF measurement. These ion TOF spectra were utilized to determine the velocity distribution of the ejected ions. While nanosecond laser ablation typically generates ions of a few tens of eV, femtosecond laser irradiation even at moderate energy densities can produce energetic ions with energies of up to a few keV. The most probable energy of these fast ions is proportional to the laser fluence. The structure and number of peaks of the TOF spectra varies with the laser fluence. Images of plume emission were captured by an intensified CCD (ICCD) camera. The plume emission spectrum was analyzed by a spectrometer. Laser ablated craters were measured by an interferometric microscope and a scanning electron microscope (SEM). Ablation yield was expressed as a function of laser fluence, and number of shots.

scholarly journals Ablation and Patterning of Carbon Nanotube Film by Femtosecond Laser Irradiation

2019 ◽  
Vol 9 (15) ◽  
pp. 3045 ◽  
Author(s):  
Xuefeng Wu ◽  
Hailiang Yin ◽  
Qiang Li
Keyword(s):  
Carbon Nanotube ◽  
Femtosecond Laser ◽  
Pulse Energy ◽  
Short Pulse ◽  
Practical Method ◽  
High Energy ◽  
Femtosecond Laser Irradiation ◽  
High Peak Power ◽  
Film Material ◽  
Large Area

Carbon nanotube (CNT) film can be used as thin film electrodes and wearable electronic devices due to their excellent mechanical and electrical properties. The femtosecond laser has the characteristics of an ultra-short pulse duration and an ultra-high peak power, and it is one of the most suitable methods for film material processing. The ablation and patterning of CNT film are performed by a femtosecond laser with different parameters. An ablation threshold of 25 mJ/cm2 was obtained by investigating the effects of laser pulse energy and pulse number on ablation holes. Raman spectroscopy and scanning electron microscope (SEM) were used to characterize the performance of the pattern groove. The results show that the oligomer in the CNT film was removed by the laser ablation, resulting in an increase in Raman G band intensity. As the laser increased, the ablation of the CNTs was caused by the energy of photons interacting with laser-induced thermal elasticity when the pulse energy was increased enough to destroy the carbon–carbon bonds between different carbon atoms. Impurities and amorphous carbon were found at and near the cut edge while laser cutting at high energy, and considerable distortion and tensile was produced on the edge of the CNTs’ groove. Furthermore, appropriate cutting parameters were obtained without introducing defects and damage to the substrate, which provides a practical method applied to large-area patterning machining of CNT film.

RIPPLE FORMATION ON InP SURFACE IRRADIATED WITH FEMTOSECOND LASER

2005 ◽  
Vol 04 (04) ◽  
pp. 779-784 ◽  
Author(s):  
H. X. QIAN ◽  
W. ZHOU ◽  
H. Y. ZHENG
Keyword(s):  
Raman Spectroscopy ◽  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Laser Fluence ◽  
Femtosecond Laser Irradiation ◽  
Laser Polarization ◽  
Polarization Direction ◽  
Micro Raman Spectroscopy ◽  
Ripple Formation ◽  
Inp Surface

Single crystalline InP was ablated with linearly p-polarized femtosecond laser in air. Ripples with orientation parallel to the laser polarization direction were formed at low laser fluence. Analyses by EDX reveal In oxides and P oxides on the surface. Micro Raman spectroscopy of the laser irradiated surface indicates presence of stresses and possible formation of InP nanocrystals due to the femtosecond laser irradiation.

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