The eigenstates of linear combinations of the Susskind and Glogower phase operators [Physics 1, 49 (1964)] for the harmonic oscillator are constructed. It is shown that such eigenstates are squeezed states.
A new set of phase operators for the electromagnetic field has been defined by an extension of squeezed-state theory. In several cases these operators have similar or the same properties as the previously defined (Susskind–Glogower) operators. However, the new operators also have unique properties of their own. The expectation values of the phase operators have been found for a squeezed state and been shown to reduce to the expected classical values in the limit of small amounts of squeezing and large field excitation.
It is pointed out that, while Suskind and Glogower claim “The phase operator for an oscillator is shown not to exist.”, they actually showed absolute phase operator, which is physically meaningless, does not exist. It is also pointed out that, they showed countably infinitely many trigonometric relative (relative between two oscillators) phase states, which form complete basis and are, in a sense, best possible quantum “phase states”, exist. In addition, continuously infinitely many phase states are constructed at classical, that is, infinitely many quanta, limit. Similarly, relative time states and operator are constructed with two oscillators with different angular velocities.