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Radical Species Generation and Their Lifetime Extension by a Femtosecond and Nanosecond Dual-Laser System
Applied Physics A: Materials Science and Processing
  • C.-H. Lin
  • Z. Liang
  • J. Zhou
  • Hai-Lung Tsai, Missouri University of Science and Technology
Abstract

For many material processes, desired radical species at excited states are produced which interact with a given substrate for a certain period of time allowing chemical reactions between them to occur and complete. Hence, it is important to maintain the population of the excited radical species for an extended period of time, i.e., their lifetime, which is defined as the time for emission intensity to decay to 1/e of the initial intensity. In this study, a femtosecond-nanosecond (fs-ns) dual-laser system was employed to generate desired radical species via the fs laser and, then, to extend the lifetime of the radical species by the ns laser with different time delays between the two fs-ns laser pulses. The proposed method is demonstrated for a N₂-CO₂ mixture with CN as the radical species. The results show that the lifetime of CN radical species can be significantly extended, particularly the (3, 3) spectral line which was extended from 30 to 200 ns. By using a wavelength-tunable ns laser, the lifetime of most radical species can be extended which may increase the process efficiency for many material processes. © 2014 Springer Verlag Berlin Heidelberg.

Department(s)
Mechanical and Aerospace Engineering
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2014 Springer Verlag, All rights reserved.
Publication Date
1-1-2014
Publication Date
01 Jan 2014
Citation Information
C.-H. Lin, Z. Liang, J. Zhou and Hai-Lung Tsai. "Radical Species Generation and Their Lifetime Extension by a Femtosecond and Nanosecond Dual-Laser System" Applied Physics A: Materials Science and Processing (2014) ISSN: 0947-8396
Available at: http://works.bepress.com/hai-lung-tsai/176/