C2 and CH rotational temperatures in diamond growth using CO2 laser-assisted combustion-flames

T. Gebre, J. Sun, H. Ling, Y. X. Han, M. Zao, Y. F. Lu

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

1 Scopus citations


Excited C2 and CH species occur abundantly in diamond growth using C2H2/O2, C2H 2/C2H4/O2 and C2H 4/O2 flames. The irradiation of some flames by a continuous-wave (CW) CO2 laser beam has resulted in increased optical emission intensity from the excited species and a change in the physical appearance of the flames due to resonant absorption of laser energy. Gas temperature in the flames is one of the most important parameters in the application of diamond growth. In atmospheric plasmas, the gas kinetic temperature is closely related to the rotational temperature of radical species in the plasmas. Optical emission spectroscopy (OES) was used to obtain molecular spectra of the excited C2 and CH species in the flames for a fixed gas ratio of C2H2/C2H4/O2 flame at several laser energies. The rotational temperatures of CH were calculated using the Boltzmann plot method. In addition, synthetic C2 molecular spectra were compared with the experimental spectra to obtain temperature by the intensity ratio of selected spectrum components. For each condition, the temperatures obtained using these methods were correlated with the quality, grain size, and growth speed of diamond films on cemented tungsten carbide (WC-Co) substrates. rotational temperature, CO2 laser, resonant absorption,.

Original languageEnglish (US)
Title of host publicationLaser-based Micro- and Nanopackaging and Assembly II
StatePublished - 2008
EventLaser-based Micro- and Nanopackaging and Assembly II - San Jose, CA, United States
Duration: Jan 22 2008Jan 24 2008

Publication series

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


ConferenceLaser-based Micro- and Nanopackaging and Assembly II
Country/TerritoryUnited States
CitySan Jose, CA


  • Boltzmann plot
  • Diamond-film growth

ASJC Scopus subject areas

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


Dive into the research topics of 'C2 and CH rotational temperatures in diamond growth using CO2 laser-assisted combustion-flames'. Together they form a unique fingerprint.

Cite this