Optimal coherent filtering for single noisy photons

We introduce a filter using a noise-free quantum buffer with large optical bandwidth that can both filter temporal-spectral modes as well as interconvert them and change their frequency. We theoretically show that such quantum buffers optimally filter out temporal-spectral noise, producing identical...

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Bibliographic Details
Main Authors: Gao, S, Lazo-Arjona, O, Brecht, B, Kaczmarek, KT, Thomas, SE, Nunn, J, Ledingham, PM, Saunders, DJ, Walmsley, IA
Format: Journal article
Language:English
Published: American Physical Society 2019
Description
Summary:We introduce a filter using a noise-free quantum buffer with large optical bandwidth that can both filter temporal-spectral modes as well as interconvert them and change their frequency. We theoretically show that such quantum buffers optimally filter out temporal-spectral noise, producing identical single photons from many distinguishable noisy single-photon sources with the minimum required reduction in brightness. We then experimentally demonstrate a noise-free quantum buffer in a warm atomic system that is well matched to quantum dots. Based on these experiments, simulations show that our buffer can outperform all intensity (incoherent) filtering schemes for increasing indistinguishability.