923 research outputs found
Experimental test of local realism using non-maximally entangled states
In this paper we describe a test of Bell inequalities using a non- maximally
entangled state, which represents an important step in the direction of
eliminating the detection loophole. The experiment is based on the creation of
a polarisation entangled state via the superposition, by use of an appropriate
optics, of the spontaneous fluorescence emitted by two non-linear crystals
driven by the same pumping laser.Comment: proc. of QCM&C, Capr
A new conception experimental test of Bell inequalities using non-maximally entangled states
We report on a test of Bell inequalities using a non-maximally entangled
state, which represents an important step in the direction of eliminating the
detection loophole. The experiment is based on the creation of a polarisation
entangled state via the superposition, by use of an appropriate optics, of the
spontaneous fluorescence emitted by two non-linear crystals driven by the same
pumping laser. The alignment has profitably taken advantage from the use of an
optical amplifier scheme, where a solid state laser is injected into the
crystals together with the pumping laser. In principle a very high total
quantum efficiency can be reached using this configuration and thus the final
version of this experiment can lead to a resolution of the detection loophole,
we carefully discuss the conditions which must be satisfied for reaching this
result.Comment: to be published in Proc. of International Workshop on Optics and
Spectroscopy (Hanoi, Vietnam
Twin-photon techniques for photo-detector calibration
The aim of this review paper is to enlighten some recent progresses in
quantum optical metrology in the part of quantum efficiency measurements of
photo-detectors performed with bi-photon states. The intrinsic correlated
nature of entangled photons from Spontaneous Parametric Down Conversion
phenomenon has opened wide horizons to a new approach for the absolute
measurement of photo-detector quantum efficiency, outgoing the requirement for
conventional standards of optical radiation; in particular the simultaneous
feature of the creation of conjugated photons led to a well known technique of
coincidence measurement, deeply understood and implemented for standard uses.
On the other hand, based on manipulation of entanglement developed for Quantum
Information protocols implementations, a new method has been proposed for
quantum efficiency measurement, exploiting polarisation entanglement in
addition to energy-momentum and time ones, that is based on conditioned
polarisation state manipulation. In this review, after a general discussion on
absolute photo-detector calibration, we compare these different methods, in
order to give an accurate operational sketch of the absolute quantum efficiency
measurement state of the art
A conclusive experiment to throw more light on "light"
We describe a new realization of Ghose, Home, Agarwal experiment on wave
particle duality of light where some limitations of the former experiment,
realized by Mizobuchi and Ohtake, are overcome. Our results clearly indicate
that wave-particle complementarity must be understood between interference and
"whelcher weg" knowledge and not in a more general sense
A Good Policy of Sustainable Tourism
We consider an extensive form game to analyze the interdependence between environmental protection of resources, the activities related with the tourism and the behavior of a local population. We answer two questions: 1) Suppose that the central planner invest in tourist activities, has he incentives to do an aggressive propagandistic campaign to convince the tourist to come for the country? 2) How good is from the environmental point of view that the local inhabitants prefer to work in tourist activities? So we analyze the situation when it's possible to obtain a sustainable tourism in a country such that the tourism is the main economic activity.Imperfect information, mixed strategies, repeated game, sustainable tourism
Toward third order ghost imaging with thermal light
Recently it has been suggested that an enhancement in the visibility of ghost
images obtained with thermal light can be achieved exploiting higher order
correlations [3]. This paper reports on the status of an higher order ghost
imaging experiment carried on at INRIM labs exploiting a pseudo-thermal source
and a CCD camera.Comment: To be published in Proceedings of Recent advances in Foundations of
Quantum Mechanics and Quantum Informatio
Experimental realization of a low-noise heralded single photon source
We present a heralded single-photon source with a much lower level of
unwanted background photons in the output channel by using the herald photon to
control a shutter in the heralded channel. The shutter is implemented using a
simple field programable gate array controlled optical switch.Comment: 4 pages, 5 figure
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