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arXiv · 2307.11103

Cross-spectral purity of the Stokes parameters in random nonstationary electromagnetic beams

Jyrki Laatikainen·Ari T. Friberg·Tero Setälä
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Abstract

We consider cross-spectral purity in random nonstationary electromagnetic beams in terms of the Stokes parameters representing the spectral density and the spectral polarization state. We show that a Stokes parameter being cross-spectrally pure is consistent with the property that the corresponding normalized time-integrated coherence (two-point) Stokes parameter satisfies a certain reduction formula. The current analysis differs from the previous works on cross-spectral purity of nonstationary light beams such that the purity condition is in line with Mandel's original definition. In addition, in contrast to earlier works concerning the cross-spectral purity of the polarization-state Stokes parameters, intensity-normalized coherence Stokes parameters are applied. It is consequently found that in addition to separate spatial and temporal coherence factors the reduction formula contains a third factor that depends exclusively on the polarization properties. We further show that cross-spectral purity implies a specific structure for the electromagnetic spectral spatial correlations. The results of this work constitute foundational advances in the interference of random nonstationary vectorial light.

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Jyrki Laatikainen, Ari T. Friberg, Tero Setälä. 2023-07-18. Cross-spectral purity of the Stokes parameters in random nonstationary electromagnetic beams. https://arxiv.org/abs/2307.11103

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