Experimental and theoretical investigation on fs-laser-induced nanostructure formation on thin gold films

2012 ◽  
Vol 24 (4) ◽  
pp. 042017 ◽  
Author(s):  
Dirk Wortmann ◽  
Jürgen Koch ◽  
Martin Reininghaus ◽  
Claudia Unger ◽  
Conny Hulverscheidt ◽  
...  
2020 ◽  
Vol 27 (4) ◽  
pp. 043107
Author(s):  
L. Torrisi ◽  
M. Rosinski ◽  
M. Cutroneo ◽  
A. Torrisi
Keyword(s):  
Fs Laser ◽  

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 535
Author(s):  
Seiya Nikaido ◽  
Takumi Natori ◽  
Ryo Saito ◽  
Godai Miyaji

This study reports the results of experiments on periodic nanostructure formation on diamond-like carbon (DLC) films induced with 800 nm, 7-femtosecond (fs) laser pulses at low fluence from a Ti:sapphire laser oscillator. It was demonstrated that 7-fs laser pulses with a high power density of 0.8–2 TW/cm2 at a low fluence of 5–12 mJ/cm2 can form a periodic nanostructure with a period of 60–80 nm on DLC films. The period decreases with increasing fluence of the laser pulses. The experimental results and calculations for a model target show that 7-fs pulses can produce a thinner metal-like layer on the DLC film through a nonlinear optical absorption process compared with that produced with 100-fs pulses, creating a finer nanostructure via plasmonic near-field ablation.


2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Patrick E. Hopkins ◽  
Leslie M. Phinney ◽  
Justin R. Serrano

In this work, we examine Fermi relaxation in 20 nm Au films with pump-probe themoreflectance using a thin film, intraband thermoreflectance model. Our results indicate that the Fermi relaxation of a perturbed electron system occurs approximately 1.10±0.05 ps after absorption of a 785 nm, 185 fs laser pulse. This is in agreement with reported values from electron emission experiments but is higher than the Fermi relaxation time determined from previous thermoreflectance measurements. This discrepancy arises due to thermoreflectance modeling and elucidates the importance of the use of a proper thermoreflectance model for thermophysical property determination in pump-probe experiments.


Nanoscale ◽  
2017 ◽  
Vol 9 (33) ◽  
pp. 12014-12024 ◽  
Author(s):  
Christian Frydendahl ◽  
Taavi Repän ◽  
Mathias Geisler ◽  
Sergey M. Novikov ◽  
Jonas Beermann ◽  
...  

fs-Laser pulses can be used to locally alter the morphology and optical properties of semi-continuous metal films in a simple laser writing process.


2011 ◽  
Author(s):  
R. Freiberger ◽  
J. Hauck ◽  
M. Reininghaus ◽  
D. Wortmann ◽  
L. Juschkin

Author(s):  
R. H. Morriss ◽  
J. D. C. Peng ◽  
C. D. Melvin

Although dynamical diffraction theory was modified for electrons by Bethe in 1928, relatively few calculations have been carried out because of computational difficulties. Even fewer attempts have been made to correlate experimental data with theoretical calculations. The experimental conditions are indeed stringent - not only is a knowledge of crystal perfection, morphology, and orientation necessary, but other factors such as specimen contamination are important and must be carefully controlled. The experimental method of fine-focus convergent-beam electron diffraction has been successfully applied by Goodman and Lehmpfuhl to single crystals of MgO containing light atoms and more recently by Lynch to single crystalline (111) gold films which contain heavy atoms. In both experiments intensity distributions were calculated using the multislice method of n-beam diffraction theory. In order to obtain reasonable accuracy Lynch found it necessary to include 139 beams in the calculations for gold with all but 43 corresponding to beams out of the [111] zone.


Author(s):  
Joseph D. C. Peng

The relative intensities of the ED spots in a cross-grating pattern can be calculated using N-beam electron diffraction theory. The scattering matrix formulation of N-beam ED theory has been previously applied to imperfect microcrystals of gold containing stacking disorder (coherent twinning) in the (111) crystal plane. In the present experiment an effort has been made to grow single-crystalline, defect-free (111) gold films of a uniform and accurately know thickness using vacuum evaporation techniques. These represent stringent conditions to be met experimentally; however, if a meaningful comparison is to be made between theory and experiment, these factors must be carefully controlled. It is well-known that crystal morphology, perfection, and orientation each have pronounced effects on relative intensities in single crystals.The double evaporation method first suggested by Pashley was employed with some modifications. Oriented silver films of a thickness of about 1500Å were first grown by vacuum evaporation on freshly cleaved mica, with the substrate temperature at 285° C during evaporation with the deposition rate at 500-800Å/sec.


Author(s):  
R. W. Vook ◽  
R. Cook ◽  
R. Ziemer

During recent experiments on Au films, a qualitative correlation between hole formation and deposition rate was observed. These early studies were concerned with films 80 to 1000A thick deposited on glass at -185°C and annealed at 170°C. In the present studies this earlier work was made quantitative. Deposition rates varying between 5 and 700 A/min were used. The effects of deposition rate on hole density for two films 300 and 700A thick were investigated.Au was evaporated from an outgassed W filament located 10 cm from a glass microscope slide substrate and a quartz crystal film thickness monitor. A shutter separating the filament from the substrate and monitor made it possible to obtain a constant evaporation rate before initiating deposition. The pressure was reduced to less than 1 x 10-6 torr prior to cooling the substrate with liquid nitrogen. The substrate was cooled in 15 minutes during which the pressure continued to drop to the mid 10-7 torr range, where deposition was begun.


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