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arXiv · 2207.11086

Propagation of Partially Coherent Light in non-Hermitian Lattices

P. A. Brandão·J. C. A. Rocha
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Abstract

Band theory for partially coherent light is introduced by using the formalism of second-order classical coherence theory under paraxial approximation. It is demonstrated that the cross-spectral density function, describing correlations between pairs of points in the field, can have bands and gaps and form a correlation band structure. The propagation of a partially coherent beam in non-Hermitian periodic structures is considered to elucidate the interplay between the degree of coherence and the gain/loss present in the lattice. We apply the formalism to study partially coherent Bloch oscillations in lattices having parity-time symmetry and demonstrate that the oscillations can be sustained in such media but they are strongly dependent upon the spatial correlations of the beam. A transition between breathing and oscillating modes is shown to be induced by the degree of spatial coherence.

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P. A. Brandão, J. C. A. Rocha. 2022-07-22. Propagation of Partially Coherent Light in non-Hermitian Lattices. https://doi.org/10.1103/physreva.106.063503

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