  We consider two kinds of superpositions of squeezed states of light. In the
case of superpositions of first kind, the squeezing and all higher order
squeezing vanishes. However, in the case of the second kind, it is possible to
achieve a maximum amount of squeezing by adjusting the parameters in the
superposition. The emergence and vanishing of squeezing for the superposition
states are explained on the basis of expectation values of the energy density.
We show that expectation values of energy density of quantum states which show
no squeezing will be always positive and that of squeezed states will be
negative for some values of spacetime-dependent phase.
