  The noise dynamics of an Optical Frequency Comb (OFC) based on a mode-locked
Ti-Sapphire laser is analyzed in terms of noise modes. A spectrally resolved
multipixel homodyne detection enables the simultaneous measurement of the
amplitude and phase noises of several optical frequency channels, from which
the covariance matrices of the amplitude and phase quadratures of the laser
field are calculated. The decomposition of these matrices into the four most
significant time/frequency modes of the field enables the tracking of the
origin of the noises and the correlations between the noise modes. In
particular, the correlations between the amplitude and phase noises are
measured. These measurements are well reproduced by a model taking into account
the correlations between the CEO phase noise and the amplitude noise induced by
the group velocity dispersion of the laser cavity.
