PHOTON DISTRIBUTION IN 2-MODE SQUEEZED COHERENT STATES WITH COMPLEX DISPLACEMENT AND SQUEEZE PARAMETERS

Two-mode squeezed coherent states with complex squeeze and displacemen t parameters are studied, taking advantage of the SU(2) dynamical symm etry underlying two-mode systems. Expressions for the photon distribut ions in such states are derived using an SU(2) identity and the fact t hat the two-mode squeeze operator can be viewed as a rotated version o f the product of reciprocal single-mode squeeze operators. An importan t U(1) X U(1) invariance of this photon distribution is established. A s a consequence, the three phases of the complex squeeze and displacem ent parameters enter the photon distribution through just one U(1) X U (1) invariant combination. An associated Gouy effect is noted. Numeric al examples of two-mode photon distributions are shown, and interestin g new features demonstrated. Second-order coherence properties and the ir nonclassical nature are briefly studied.