|
报告内容
摘要
|
As a standard method
for producing correlated photon pairs (biphotons), spontaneous parametric
down-conversion in nonlinear crystal usually has a wide bandwidth
(terahertz) and very short coherence time (pico-seconds). Within spontaneous
four-wave mixing process in cold atom ensembles, here we present a
method for producing narrow-band (megahertz) Stokes and anti-Stokes paired
photons. As detecting a Stokes photon heralds the generation of its paired
anti-Stokes photon, the biphoton source is also used as a good heralded single
photon source. With narrow-band frequency-tunable entangled biphotons, we
observe coalescence interference for both degenerate and nondegenerate
photons, and find that the path-exchange symmetry plays a more important role
in the Hong-Ou-Mandel interference than the temporal or frequency
indistinguishability. Based on a direct modulation of heralded single-photon
waveform with an arbitrary phase pattern, we demonstrate the first proof of
principle differential phase shift quantum key distribution experiment using
heralded single photons. When the single-photon waveform is modulated to
exponential growth, we experimentally demonstrate that a single photon can be
almost completely loaded into a Fabry-Perot cavity, which has a potential
application in cavity Quantum Electrodynamics field.
|
