K. Nyholm, 2-DIMENSIONAL IMAGING OF OH IN A FLAME BY USING DEGENERATE 4-WAVE-MIXING IN A FORWARD GEOMETRY, Applied physics. B, Lasers and optics, 64(6), 1997, pp. 707-712
The use of degenerate four-wave mixing in a three-dimensional, forward
four-wave mixing geometry for two-dimensional imaging of combustion s
pecies is reported. In this configuration, a beam of circular cross se
ction intersects in the flame the crossing area of two beams that have
been focused to form thin sheets of light. The generated signal beam
propagates in the direction that fulfills the phase matching condition
and, therefore, is spatially separated from the other beams. The thin
intersection volume of the three beams is imaged onto a detector. Thu
s, information on the signal distribution in one plane in the sample c
an be recorded. The method is demonstrated with experiments performed
on OH molecules in a premixed acetylene-oxygen flame.