0
Research Papers

Ultrafast Laser Induced Structural Modification of Fused Silica—Part II: Spatially Resolved and Decomposed Raman Spectral Analysis

[+] Author and Article Information
Siniša Vukelić, Panjawat Kongsuwan, Y. Lawrence Yao

Department of Mechanical Engineering, Columbia University, New York, NY 10027

Sunmin Ryu

Department of Chemistry, Columbia University, New York, NY 10027

J. Manuf. Sci. Eng 132(6), 061013 (Dec 17, 2010) (9 pages) doi:10.1115/1.4002768 History: Received July 27, 2010; Revised August 08, 2010; Published December 17, 2010; Online December 17, 2010

Nonlinear absorption of femtosecond laser pulses enables the induction of structural changes in the interior of bulk transparent materials without affecting their surface. In the present study, femtosecond laser pulses were tightly focused within the interior of bulk fused silica specimen. Localized plasma was formed, initiating rearrangement of the random network structure. Cross sections of the induced features were examined via decomposition of spatially resolved Raman spectra and a new method for the quantitative characterization of the structure of amorphous fused silica was developed. The proposed method identifies the volume fraction distribution of ring structures within the continuous random network of the probed volume of the target material and changes of the distribution with laser process conditions. Effects of the different process conditions and the material response to different mechanisms of feature generation were discussed as well.

FIGURES IN THIS ARTICLE
<>
Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 2

Ball and stick model of the random network in the fused silica, showing threefold and fourfold ring structures (encircled)

Grahic Jump Location
Figure 3

Typical Raman spectra of as-received fused silica sample

Grahic Jump Location
Figure 4

Typical normalized Raman spectra reference and spectra from fused silica processed with pulse energy: 30 μJ at feed rates 0.04 mm/s, 0.5 mm/s, and 1 mm/s

Grahic Jump Location
Figure 5

Curve fit and decomposition of the typical Raman spectra in the fused silica treated with femtosecond laser pulses of 30 μJ energy: (a) without fluorescence at feed rate 1 mm/s and (b) taking fluorescence into account at feed rate 0.04 mm/s

Grahic Jump Location
Figure 6

Volume fraction distribution of five- and six-membered rings based on the 440 cm−1 peak in Raman spectra of cross section of laser-irradiated region pulse energy 30 μJ and feed rates: (a) 1 mm/s, (b) 0.5 mm/s, and (c) 0.04 mm/s

Grahic Jump Location
Figure 7

Volume fraction distribution of four-membered rings based on the 495 cm−1 peak in Raman spectra of cross section of laser-irradiated region pulse energy 30 μJ and feed rates: (a) 1 mm/s, (b) 0.5 mm/s, and (c) 0.04 mm/s

Grahic Jump Location
Figure 8

Volume fraction distribution of three-membered rings based on the 606 cm−1 peak in Raman spectra of cross section of laser-irradiated region pulse energy 30 μJ and feed rates: (a) 1 mm/s, (b) 0.5 mm/s, and (c) 0.04 mm/s

Grahic Jump Location
Figure 1

Schematic illustration experimental setup. The shadowed plane (cross section) shows that the laser beam is focused to the interior of our fused silica sample. Laser beam scanning direction is along y-axis.

Grahic Jump Location
Figure 9

Volume fraction change of n-membered rings along the lateral direction within cross section: (a) five- and six-membered ring structures, 440 cm−1, (b) four-membered ring structures, 495 cm−1, and (c) three-membered ring structures, 606 cm−1

Tables

Errata

Discussions

Related

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.

Related Journal Articles
Related eBook Content
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