138 research outputs found
Revealing single emitter spectral dynamics from intensity correlations in an ensemble fluorescence spectrum
We show that the single emitter linewidth underlying a broadened ensemble
emission spectrum can be extracted from correlations among the stochastic
intensity fluctuations in the ensemble spectrum. Spectral correlations can be
observed at high temporal and spectral resolutions with a cross-correlated pair
of avalanche photodiodes placed at the outputs of a scanning Michelson
interferometer. As illustrated with simulations in conjunction with
Fluorescence Correlation Spectroscopy, our approach overcomes ensemble and
temporal inhomogeneous broadening to provide single emitter linewidths, even
for emitters under weak, continuous, broadband excitation.Comment: 9 pages, 5 figure
Experimental observation of Aharonov-Bohm caging using orbital angular momentum modes in optical waveguides
The discovery of artificial gauge fields, controlling the dynamics of
uncharged particles that otherwise elude the influence of standard electric or
magnetic fields, has revolutionized the field of quantum simulation. Hence,
developing new techniques to induce those fields is essential to boost quantum
simulation in photonic structures. Here, we experimentally demonstrate in a
photonic lattice the generation of an artificial gauge field by modifying the
input state, overcoming the need to modify the geometry along the evolution or
imposing the presence of external fields. In particular, we show that an
effective magnetic flux naturally appears when light beams carrying orbital
angular momentum are injected into waveguide lattices with certain
configurations. To demonstrate the existence of that flux, we measure the
resulting Aharonov-Bohm caging effect. Therefore, we prove the possibility of
switching on and off artificial gauge fields by changing the topological charge
of the input state, paving the way to access different topological regimes in
one single structure, which represents an important step forward for optical
quantum simulation
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