  In order to obtain a classification of all possible quantum deformations of
the two-photon algebra $h_6$, we introduce its corresponding general Lie
bialgebra, which is a coboundary one. Two non-standard quantum deformations of
$h_6$, together with their associated quantum universal R-matrix, are
presented; each of them contains either a quantum harmonic oscillator
subalgebra or a quantum gl(2) subalgebra. One-boson representations for these
quantum two-photon algebras are derived and translated into Fock--Bargmann
realizations. In this way, a systematic study of `deformed' states of light in
quantum optics can be developed.
