José Brito

Telecom-heralded single-photon absorption by a single atom

We present, characterize, and apply the architecture of a photonic quantum interface between the near infrared and telecom spectral regions. A singly resonant optical parametric oscillator (OPO) operated below threshold, in combination with external filters, generates high-rate (

Coherence and entanglement preservation of frequency-converted heralded single photons

g2.5\ifmmode\times\else\texttimes\fi{}{10}^{6}\phantom{\rule{0.222222em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}

Superresolution imaging in optical tweezers using high-speed cameras.

) narrowband photon pairs (

Three-dimensional clustered speckle fields: theory, simulations and experimental verification

\ensuremath{\sim}7

Doubly heralded single-photon absorption by a single atom

MHz bandwidth); the signal photons are tuned to resonance with an atomic transition in

Single telecom photon heralding by wavelength multiplexing in an optical fiber

{\mathrm{Ca}}^{+}

Emission and Absorption of Single Photons by Single Atoms

, while the idler photons are at telecom wavelength. Interface operation is demonstrated through high-rate absorption of single photons by a single trapped ion (

Superresolution Imaging and Force Characterization of Optical Tweezers Using High-Speed Cameras

\ensuremath{\sim}670\phantom{\rule{0.222222em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}

A clustered speckle approach to optical trapping

), heralded by coincident telecom photons.

Frequency conversion of narrowband single photons from a SPDC pair source

We report on quantum frequency conversion of near-infrared photons from a wave-length of 854 nm to the telecommunication O-band at 1310 nm with 8 % overall conversion efficiency. Entangled photon pairs at 854 nm are generated via type-II spontaneous parametric down conversion. One photon is mixed with a strong pump field in a nonlinear ridge waveguide for its conversion to 1310 nm. We demonstrate preservation of first and second order coherence of the photons in the conversion process. Based on this we infer the coherence function of the two-photon state and compare it with the actual measured one. This measurement demonstrates preservation of time-energy entanglement of the pair. With 88 % visibility we violate a Bell inequality.