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Observation of triply coincident nonlinearities in periodically poled KTiOPO4

Raphael C. Pooser·Olivier Pfister
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Abstract

We report the simultaneous quasi-phase-matching of all three possible nonlinearities for propagation along the X axis of periodocally poled (PP) KTiOPO4 (KTP) for second-harmonic generation of 745 nm pulsed light from 1490nm subpicosecond pulses in a PPKTP crystal with a 45.65 micrometer poling period. This confirms the recent Sellmeier fits of KTP by K. Kato and E. Takaoka [Appl. Opt. 41, 5040 (2002)]. Such coincident nonlinearities are of importance for realizing compact sources of multipartite continuous-variable entanglement [Pfister et al., Phys. Rev. A 70, 020302 (2004)] and we propose a new simpler method for entangling four fields, based on this triple coincidence.

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Raphael C. Pooser, Olivier Pfister. 2005-05-17. Observation of triply coincident nonlinearities in periodically poled KTiOPO4. https://doi.org/10.1364/ol.30.002635

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