Unpolarized light states in quantum optics

F. Rocca

Wolfgang Elsäßer, Florian Kroh, Markus Rosskopf

We investigate the polarization properties of unpolarized light, first in the temporal domain realized by $1.55 \mu \mathrm{m}$ ASE light emitted by an erbium-doped fiber amplifier and second in the spatial domain by exploiting the polarization dispersion of a Cornu depolarizer. We find novel Stokes parameter correlations and invariances for temporally unpolarized light and novel states on the Poincaré sphere for spatially unpolarized light. All these results give new fresh insight into the field of classical polarization with interesting promising quantum and sensing application perspectives.

D. S. Krähmer, Ulf Leonhardt

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 53, 2727 (1996)] via optical homodyne tomography. Our analysis can be extended 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 operator applied to the quadrature distribution of unpolarized photons is orthogonal on the set of these distributions.

V. P. Karasev, V. I. Puzyrevskii

Jonas Söderholm, Gunnar G. Bjork, Alexei S. Trifonov

We present a new derivation of the unpolarized quantum states of light, whose general form was first derived by Prakash and Chandra [6]. Our derivation makes use of some basic group theory, is straightforward, and offers some new insights.

Klaus M. Gheri, Daniel F. Walls