Propagation of Non-Classical Light

Ivan V. Panyukov, E. S. Andrianov

Statistical properties of light produced in spontaneous Raman scattering on an ensemble of molecules indicate the quantum nature of this phenomenon. The scattered light is non-classical and has high non-classical intensity correlations between Stokes and anti-Stokes components. The temporal coherence of this light is well investigated, while many questions related to spatial coherence remain open. Recent experiments reveal two peculiar features of the spatial coherence of the Stokes and anti-Stokes light. First, the intensity correlations between Stokes and anti-Stokes light remain non-classical even for macroscopic samples containing many molecules. Second, these correlations decrease when signal propagates through a multi-mode optical fiber: the more propagating fiber modes at Stokes and anti-Stokes frequencies the less the correlations. Moreover, the second-order autocorrelation function of Stokes and anti-Stokes light also decreases with the number of propagating modes in multi-mode fiber. In this paper, we build a model of spontaneous Raman scattering correlations of light produced by an ensemble of molecules and propagating through weakly guiding optical fiber that quantitatively explains all these observations. We show that spacial orthogonality of the fiber modes makes the light propagating through these modes uncorrelated in the standard detection scheme. This leads to suppression of non-classical intensity correlations of the total field in the multi-mode fiber. We find the degree of non-classical correlations on fiber parameters. The obtained results pave the way for engineering of non-classical Stokes -- anti-Stokes correlations.

А. В. Белинский, Давид Николаевич Клышко

R. Loudon

The theoretical descriptions of the main varieties of non–classical light and the principal measures of their specifically quantum properties are outlined. The theories of quantum–optical propagation of the light through slabs of amplifying or attenuating materials are presented and the main features of the quantum noise effects produced by transmission are summarized. It is found that, while quantum light may have lower noise than classical coherent light, transmission through the slab generally increases the noise. Thus initial enthusiasm for practical low–noise advantages of non–classical light has been tempered by the realization that most kinds of optical propagation or processing enhance the noise to near–classical levels.

Aleksandr V. Belinsky, Давид Николаевич Клышко

Antonín Luk¿, Vlasta Peřinová

Hugo Defienne, Marco Barbieri, Bénoît Chalopin +4 more

In this work, we use wavefront shaping methods to control non-classical states of light propagating through a multiply scattering medium. We experimentally show guiding of a single-photon into a selected single-mode fiber after propagation through the medium, and demonstrate generation of a one-photon entangled state.