OPTICAL HOMODYNE TOMOGRAPHY OF UNPOLARIZED LIGHT

We show how to reconstruct the quantum state of completely unpolarized light of type I [J. Lehner, U. Leonhardt, and H. Paul, Phys. Rev. A 5 3, 2727 (1996)] via optical homodyne tomography. Our analysis can be e xtended to any two-mode situation with complete two-mode randomization and, moreover, to any two-dimensional harmonic oscillator with SU(2) symmetric states. Interestingly, we have shown that the Laplace operat or applied to the quadrature distribution of unpolarized photons is or thogonal on the set of these distributions.