Resonant excitation of ethylene molecules in the combustion flame CVD of diamond using a wavelength tunable CO2 laser

Z. Q. Xie, J. B. Park, X. N. He, Y. Gao, Y. S. Zhou, Y. F. Lu

Research output: Chapter in Book/Report/Conference proceedingConference contribution


CO2 laser resonant excitations of precursor molecules were applied in combustion flame synthesis of diamond films. The combustion flame was produced from a mixture of ethylene (C2H4), acetylene (C2H2) and oxygen (O2). A wavelength-tunable CO2 laser with wavelength range from 9.2 to 10.9 μm was used for wavelength-matched excitation of the ethylene molecules. By irradiating the flame using CO2 laser at 10.532 μm, the ethylene molecules were resonantly excited through the CH2 wagging vibrational mode (ν7, 949.3 cm-1). Irradiation of the flame using the common CO2 laser wavelength at 10.591 μm was also carried out for comparison. It was found that diamond synthesis was more obviously enhanced by the CO2 laser resonant excitation at 10.532 μm as compared to that at 10.591 μm. Firstly, the flame was shortened by 50%, indicating a promoted reaction in the process. Secondly, the diamond grain sizes as well as the diamond film thicknesses were increased by 200~300% and 160% respectively, indicating a higher growth rate of diamond films. Finally, Raman spectra of the diamond sample showed a sharp diamond peak at 1334 cm-1 and a suppressed G-band, indicating higher diamond quality.

Original languageEnglish (US)
Title of host publicationLaser-based Micro- and Nanopackaging and Assembly IV
StatePublished - 2010
EventLaser-based Micro- and Nanopackaging and Assembly IV - San Francisco, CA, United States
Duration: Jan 26 2010Jan 28 2010

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


ConferenceLaser-based Micro- and Nanopackaging and Assembly IV
Country/TerritoryUnited States
CitySan Francisco, CA


  • Diamond
  • Resonant excitation
  • Tunable CO laser
  • Vibrational modes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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