  By the complex multimode Bogoliubov transformation, we obtain the general
forms of squeeze operators and squeezed states including squeezed vacuum
states, squeezed coherent states, squeezed Fock states and squeezed coherent
Fock states, for a general multimode boson system. We decompose the squeezed
operator into disentangling form in normal ordering to simplify the expressions
of the squeezed states. We also calculate the statistical properties of the SS.
Furthermore we prove that if it is non-degenerate, a Bogoliubov transformation
matrix can be decomposed into three basic matrix, by which we can not only
check the criterion of the minimum uncertainty state (MUS) found by Milburn,
but also prove that except the special cases, any multimode squeezed state is
MUS after the original creation and annihilation operators rotate properly. We
also discuss some special cases of the three basic matrices. Finally we give an
analytical results of a two-mode system as an example.
