  There have been experimental and theoretical studies on Photoluminescence
(PL) from possible exciton superfluid in semiconductor electron-hole bilayer
systems. However, the PL contains no phase information and no photon
correlations, so it can only lead to suggestive evidences. It is important to
identify smoking gun experiments which can lead to convincing evidences. Here
we study two mode phase sensitive squeezing spectrum and also two photon
correlation functions. We find the emitted photons along all tilted directions
are always in a two mode squeezed state between $ \vec{k} $ and $ - \vec{k} $.
There are always two photon bunching, the photon statistics is
super-Poissonian. Observing these unique features by possible future phase
sensitive homodyne experiment and HanburyBrown-Twiss type of experiment could
lead to conclusive evidences of exciton superfluid in these systems.
