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arXiv:1012.3123 · Optics Letters

Testing spectral filters as Gaussian quantum optical channels

K. Laiho, A. Christ, K. N. Cassemiro, C. Silberhorn

Published Apr 15, 2011• 16 citations
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Abstract

We experimentally investigate the mode characteristics of multimode radiation fields propagating through frequency-dependent Gaussian channels. After manipulating the twin beams emitted from a conventional parametric downconversion source via spectral filtering, we study the changes in their mode characteristics, utilizing the joint normalized correlation functions. While filtering reduces the number of spectral modes, it also leads to an apparent mode mismatch, which destroys the perfect photon-number correlation between the twin beams, and influences the mode properties of heralded states.

DOI
10.1364/ol.36.001476

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We experimentally investigate the mode characteristics of multimode radiation fields propagating through frequency-dependent Gaussian channels. After manipulating the twin beams emitted from a conventional parametric downconversion source via spectral filtering, we study the changes in their mode characteristics, utilizing the joint normalized correlation functions. While filtering reduces the number of spectral modes, it also leads to an apparent mode mismatch, which destroys the perfect photon-number correlation between the twin beams, and influences the mode properties of heralded states.
We experimentally investigate the mode characteristics of multimode radiation fields propagating through frequency-dependent Gaussian channels. After manipulating the twin beams emitted from a conventional parametric downconversion source via spectral filtering, we study the changes in their mode characteristics, utilizing the joint normalized correlation functions. While filtering reduces the number of spectral modes, it also leads to an apparent mode mismatch, which destroys the perfect photon-number correlation between the twin beams, and influences the mode properties of heralded states. (c) 2011 Optical Society of America
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Parametric down-conversion (PDC) offers the possibility to control the fabrication of non-Gaussian states such as Fock states. However, in conventional PDC sources energy and momentum conservation introduce strict frequency and photon number correlations, which impact the fidelity of the prepared state. In our work we optimize the preparation of single-photon Fock states from the emission of waveguided PDC via spectral filtering. We study the effect of correlations via photon number resolving detection and quantum interference. Our measurements show how the reduction of mixedness due to filtering can be evaluated. Interfering the prepared photon with a coherent state we establish an experimentally measured fidelity of the produced target state of 78%. (C) 2009 Optical Society of America
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