Unity-Efficiency Parametric Down-Conversion via Amplitude Amplification

We propose an optical scheme, employing optical parametric down-converters interlaced with nonlinear sign gates (NSGs), that completely converts an n-photon Fock-state pump to n signal-idler photon pairs when the down-converters’ crystal lengths are chosen appropriately. The proof of this assertion...

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Bibliographic Details
Main Authors: Sanders, Barry C., Niu, Yuezhen, Wong, Ngai Chuen, Shapiro, Jeffrey H
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: American Physical Society 2017
Online Access:http://hdl.handle.net/1721.1/109163
https://orcid.org/0000-0002-0013-416X
https://orcid.org/0000-0003-1998-6159
https://orcid.org/0000-0002-6094-5861
Description
Summary:We propose an optical scheme, employing optical parametric down-converters interlaced with nonlinear sign gates (NSGs), that completely converts an n-photon Fock-state pump to n signal-idler photon pairs when the down-converters’ crystal lengths are chosen appropriately. The proof of this assertion relies on amplitude amplification, analogous to that employed in Grover search, applied to the full quantum dynamics of single-mode parametric down-conversion. When we require that all Grover iterations use the same crystal, and account for potential experimental limitations on crystal-length precision, our optimized conversion efficiencies reach unity for 1≤n≤5, after which they decrease monotonically for n values up to 50, which is the upper limit of our numerical dynamics evaluations. Nevertheless, our conversion efficiencies remain higher than those for a conventional (no NSGs) down-converter.