  We analyze the quantum properties of the light generated by a three-level
laser with a closed cavity and coupled to a vacuum reservoir. The three-level
atoms available in the cavity are pumped from the bottom to the top level by
means of electron bombardment and we carry out our analysis by putting the
noise operators associated with the vacuum reservoir in normal order. The
maximum quadrature squeezing of the light generated by the laser, operating far
below threshold, is found to be 50% below the coherent-state level. We have
also established that the quadrature squeezing of the output light is equal to
that of the cavity light and has the same value in any frequency interval. This
implies that the quadrature squeezing of the laser light is an intrinsic
property of the individual photons.
