  First, we have generalized the notion of Franhoufer diffraction of temporal
coherent light from a single slit to the case of arbitrary n-slits. The
diffraction pattern is investigated for different values of recently [19]
introduced parameter, decoherence parameter. It is shown that for multi-slits,
the temporal decoherence effects appear for the values of decoherence parameter
equal or bigger than 1 namely the coherence length is shorter that the size of
the slits. Results of our study reproduce the previous studies for perfect
temporal case, when coherence length tends to infinity. Then to bring the
problem closer to reality, we do not fix the coherence length and consider a
Gaussian distribution function for it. Numerical study of the effects of
coherence parameters of Gaussian distribution on far field diffraction pattern
is performed.
