Gain-induced spectral non-degeneracy in type-II parametric down-conversion

• URL: http://arxiv.org/abs/2603.01656v1
• Date: Mon, 02 Mar 2026 09:39:00 GMT
• Title: Gain-induced spectral non-degeneracy in type-II parametric down-conversion
• Authors: Behnood Taheri, Denis Kopylov, Manfred Hammer, Torsten Meier, Jens Förstner, Polina Sharapova,
• Abstract summary: We demonstrate the novel effect of gain-induced spectral shifts in the type-II parametric down-conversion (PDC) process.<n>The effect, originating from the second-order dispersion terms, significantly alters the properties of PDC in the high-gain regime.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We demonstrate the novel effect of gain-induced spectral shifts in the type-II parametric down-conversion (PDC) process, which results in a transition from degenerate to non-degenerate PDC with increasing parametric gain. This effect, originating from the second-order dispersion terms, significantly alters the properties of PDC in the high-gain regime, where it leads to increased distinguishability of the generated photon pairs. The effect is established by evaluating a rigorous theoretical model, which is based on solving a system of coupled integro-differential equations for monochromatic operators. The widely used spatially-averaged approximate model fails to reproduce this important effect.

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