  The connection between quantum optical nonclassicality and the violation of
Bell's inequalities is explored. Bell type inequalities for the electromagnetic
field are formulated for general states(arbitrary number or photons, pure or
mixed) of quantised radiation and their violation is connected to other
nonclassical properties of the field. Classical states are shown to obey these
inequalities and for the family of centered Gaussian states the direct
connection between violation of Bell-type inequalities and squeezing is
established.
