PHASE VARIANCE OF SQUEEZED STATES

We relate the phase uncertainty of squeezed states (ss) to two-photon phase operators. This uncertainty tends to zero for strong squeezing in vacuum ss. For displaced ss, we distinguish between amplitude squeezing and phase squeezing. For the latter case the phase uncertainty tends to zero for strong squeezing. This result follows from our definition of two-photon phase uncertainty, in contrast to the large uncertainty which is obtained in the usual definition of one-photon phase uncertainty.