0
RESEARCH PAPERS: Micro/Nanoscale Heat Transfer

Energy Transport and Nanostructuring of Dielectrics by Femtosecond Laser Pulse Trains

[+] Author and Article Information
Lan Jiang

Laser-Based Manufacturing Laboratory, Department of Mechanical and Aerospace Engineering, University of Missouri-Rolla, Rolla, MO 65409

Hai-Lung Tsai

Laser-Based Manufacturing Laboratory, Department of Mechanical and Aerospace Engineering, University of Missouri-Rolla, Rolla, MO 65409tsai@umr.edu

J. Heat Transfer 128(9), 926-933 (May 02, 2006) (8 pages) doi:10.1115/1.2241979 History: Received December 21, 2005; Revised May 02, 2006

This study analyzes single burst ablation of dielectrics by a femtosecond pulse train that consists of one or multiple pulses. It is found that (1) there exist constant-ablation-depth zones with respect to fluence for one or multiple pulses per train and (2) for the same total fluence per train, although the ablation depth decreases in multiple pulses as compared to that of a single pulse, the depth of the constant-ablation-depth zone decreases. In other words, repeatable structures at the desired smaller nanoscales can be achieved in dielectrics by using the femtosecond pulse train technology, even when the laser fluence is subject to fluctuations. The predicted trends are in agreement with published experimental data.

FIGURES IN THIS ARTICLE
<>
Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

The theoretical and experimental threshold fluences and ablation depths as a function of pulse duration by a single pulse at the fluence of 5J∕cm2 and the wavelength of 780nm

Grahic Jump Location
Figure 4

Center (r=0) laser intensity distributions: (a) single pulse per train at 5J∕cm2 per pulse (also considered as 2 pulses at 2.5J∕cm2 with 0 pulse separation); (b) 2 pulses per train at 2.5J∕cm2 per pulse (pulse separation is 50fs); (c) 2 pulses per train at 2.5J∕cm2 per pulse (pulse separation is 100fs); (d) 2 pulses per train at 2.5J∕cm2 per pulse (pulse separation is 300fs)

Grahic Jump Location
Figure 5

The reflectivity at r=0 at different pulse separation times: (a) transient reflectivity and (b) integrated reflectivity

Grahic Jump Location
Figure 6

The ablation depth as a function of total fluence per train; the separation time between pulses for double pulses is 300fs and for triple pulses is 200fs

Grahic Jump Location
Figure 7

Surface center integrated reflectivity and absorption coefficient at t=425fs (the end of the second pulse) under the double-pulse train with separation time of 300fs

Grahic Jump Location
Figure 2

Ablation crater shapes by pulse trains consisting of double pulses with the total fluence of 5J∕cm2

Grahic Jump Location
Figure 3

(a) Laser intensity distribution and (b) electron density at r=0, z=1nm for double-pulse train with the total fluence of 5J∕cm2 and pulse separation of 100fs

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In