  In this stu dy, two dimensional ( 2D correlation analysis wa s utilized for
achieving a significant improvement in the signal to noise (S/N) ratio of laser
induced breakdown spectroscopy (LIBS) data . Time resolved LIBS spectra of
metallic, bimetal lic targets and the normal LIBS spectra of bimetallic targets
with varying compositions were used for the detailed analysis . The diagonal of
the matrix in the synchronous spectra was used to demonstrate the improvement
in the S/N ratio. An improvemen t in the peak intensities by few order s of
magnitude accompanied by suppression in the noise was observed. The
correlations between LIBS peaks were also visualized using 2 D plots.
Correlation strengths of atomic transitions were visualized in Aluminum (Al),
Copper (Cu), and Brass whereas correlation strengths of atomic, atomic, and
ionic transitions were visualized in Au Ag bimetallic targets with different
compositions (Au30Ag70, Au50Ag50, Au80 Ag20). The improved spectra were
subsequently used in the principal component analysis for classification
studies of four compositions of bimetallic targets Au20Ag80, Au30Ag70, Au50
Ag50, and Au80Ag20 The variance of the first three principal components were
found to be improved from the analysis. The accumulated percentage of explained
variance of 95 was achieved with the first three components from improved
spectra whereas only ~ 80 was achieved with the regular LIBS spectra from PCA
studies
