OSA's Digital Library

Applied Optics

Applied Optics


  • Vol. 37, Iss. 9 — Mar. 20, 1998
  • pp: 1607–1616

Laser-Induced Incandescence: Excitation Intensity

Randall L. Vander Wal and Kirk A. Jensen  »View Author Affiliations

Applied Optics, Vol. 37, Issue 9, pp. 1607-1616 (1998)

View Full Text Article

Acrobat PDF (669 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



Assumptions of theoretical laser-induced incandescence (LII) models along with possible effects of high-intensity laser light on soot aggregates and the constituent primary particles are discussed in relation to selection of excitation laser fluence. <i>Ex situ</i> visualization of laser-heated soot by use of transmission electron microscopy reveals significant morphological changes (graphitization) induced by pulsed laser heating. Pulsed laser transmission measurements within a premixed laminar sooting flame suggest that soot vaporization occurs for laser fluences greater than 0.5 J/cm<sup>2</sup> at 1064 nm. Radial LII intensity profiles at different axial heights in a laminar ethylene gas jet diffusion flame reveal a wide range of signal levels depending on the laser fluence that is varied over an eight fold range. Results of double-pulse excitation experiments in which a second laser pulse heats <i>in situ</i> the same soot that was heated by a prior laser pulse are detailed. These two-pulse measurements suggest varying degrees of soot structural change for fluences below and above a vaporization threshold of 0.5 J/cm<sup>2</sup> at 1064 nm. Normalization of the radial-resolved LII signals based on integrated intensities, however, yields self-similar profiles. The self-similarity suggests robustness of LII for accurate relative measurement of soot volume fraction despite the morphological changes induced in the soot, variations in soot aggregate and primary particle size, and local gas temperature. Comparison of LII intensity profiles with soot volume fractions (<i>f</i><sub><i>v</i></sub>) derived by light extinction validates LII for quantitative determination of <i>f</i><sub><i>v</i></sub> upon calibration for laser fluences ranging from 0.09 to 0.73 J/cm<sup>2</sup>.

© 1998 Optical Society of America

OCIS Codes
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.1740) Instrumentation, measurement, and metrology : Combustion diagnostics
(140.0140) Lasers and laser optics : Lasers and laser optics

Randall L. Vander Wal and Kirk A. Jensen, "Laser-Induced Incandescence: Excitation Intensity," Appl. Opt. 37, 1607-1616 (1998)

Sort:  Author  |  Year  |  Journal  |  Reset


  1. R. L. Vander Wal, “Laser-induced incandescence: detection issues,” Appl. Opt. 35, 6548–6559 (1996).
  2. A. C. Eckbreth, “Effects of laser-modulated particulate incandescence on Raman scattering diagnostics,” J. Appl. Phys. 48, 4473–4483 (1977).
  3. L. A. Melton, “Soot diagnostics based on laser heating,” Appl. Opt. 23, 2201–2208 (1984).
  4. C. J. Dasch, “Continuous-wave probe laser investigation of laser vaporization of small soot particles in a flame,” Appl. Opt. 23, 2209–2215 (1984).
  5. D. L. Hofeldt, “Real-time soot concentration measurement technique for engine exhaust streams,” SAE Tech. Paper 930079 (Society of Automotive Engineers, Warrendale, Pa., 1993).
  6. J. Appel, B. Jungfleisch, M. Marquardt, R. Suntz, and H. Bockhorn, “Assessment of soot volume fractions from laser-induced incandescence by comparison with extinction measurements in laminar, premixed, flat flames,” in Twenty-Sixth Symposium (International) on Combustion (The Combustion Institute, Pittsburg, Pa., 1996), pp. 2387–2396.
  7. S. Will, S. Schraml, and A. Leipertz, “Comprehensive two-dimensional soot diagnostics based on laser-induced incandescence,” in Twenty-Sixth Symposium (International) on Combustion (The Combustion Institute, Pittsburg, Pa., 1996), pp. 2277–2284.
  8. R. L. Vander Wal, M. Y. Choi, and K.-O. Lee, “The effects of rapid heating of soot: implications when using laser-induced incandescence for soot diagnostics,” Combust. Flame 102, 200–204 (1995).
  9. C. M. Megaridis and R. A. Dobbins, “Comparison of soot growth and oxidation in smoking and non-smoking ethylene diffusion flames,” Combust. Sci. Technol. 66, 1–16 (1989).
  10. F. A. Heckman, “Microstructure of carbon black,” J. Rubber Chem. Technol. 37, 1245–1298 (1967).
  11. P.-E. Bengtsson and M. Alden, “Soot visualization strategies using laser techniques,” J. Appl. Phys. B 60, 51–59 (1995).
  12. R. L. Vander Wal and K. J. Weiland, “Laser-induced incandescence: development and characterization towards measurement of soot volume fraction,” J. Appl. Phys. B 59, 445–452 (1994).
  13. T. Ni, J. A. Pinson, S. Gupta, and R. J. Santoro, “Two-dimensional imaging of soot volume fraction by the use of laser-induced incandescence,” Appl. Opt. 34, 7083–7091 (1995).
  14. C. E. Shaddix, J. E. Harrington, and K. C. Smyth, “Quantitative measurements of enhanced soot production in a flickering methane/air flame,” Combust. Flame 99, 723–732 (1994).
  15. B. Quay, T. W. Lee, T. Ni, and R. J. Santoro, “Spatially resolved measurements of soot volume fraction using laser-induced incandescence,” Combust. Flame 97, 394–395 (1994).
  16. C. R. Shaddix and K. C. Smyth, “Laser-induced incandescence measurements of soot production in steady and flickering methane, propane and ethylene diffusion flames,” Combust. Flame 107, 418–452 (1996).
  17. M. Y. Choi and K. A. Jensen, “Calibration and correction of laser-induced incandescence for soot volume fraction measurements,” Combust. Flame 112, 485–491 (1998).
  18. P. S. Greenberg and J. C. Ku, “Soot volume fraction imaging,” Appl. Opt. 36, 5514–5522 (1997).
  19. J. M. Khosrofian and B. A. Garetz, “Measurement of a Gaussian beam diameter through the direct inversion of knife edge data,” Appl. Opt. 22, 3406–3410 (1983).
  20. R. J. Santoro, H. G. Semerjian, and R. A. Dobbins, “Soot particle measurements in diffusion flames,” Combust. Flame 51, 203–218 (1983).
  21. P. A. Marsh, A. Voet, T. J. Mullens, and L. D. Price, “Electron micrography of interplanar spacings in carbon blacks,” J. Rubber Chem. Technol. 43, 470–481 (1970).
  22. D. Ugarte, “Formation mechanisms of quasi-spherical carbon particles induced by electron bombardment,” Chem. Phys. Lett. 207, 474–479 (1993).
  23. Y. Saito, “Nanoparticles and filled nanocapsules,” Carbon 33, 979–988 (1995).
  24. R. Vander Wal, “Pulsed laser heating of soot: morphological changes,” Carbon (to be published).
  25. Z. G. Habib and P. Vervisch, “On the refractive index of soot at flame temperature,” Combust. Sci. Technol. 59, 261–274 (1988).
  26. W. H. Dalzell and A. L. Sarofim, “Optical constants of soot and their application to heat flux calculations,” J. Heat Transfer 91, 100–104 (1969).
  27. J. C. Ku and K.-H. Shim, “A comparison of solutions for light scattering and absorption by agglomerated or arbitrarily shaped particles,” J. Quant. Spectrosc. Radiat. Transfer 47, 201–220 (1992).
  28. C. M. Megardis and R. A. Dobbins, “Comparison of soot growth and oxidation in smoking and nonsmoking ethylene diffusion flames,” Combust. Sci. Technol. 66, 1–16 (1989).
  29. R. J. Santoro, Pennsylvania State University, University Park, Pa. (personal communication, October 1996).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited