46 research outputs found
Measurement of Coupling PDC photon sources with single-mode and multimode optical fibers
We investigate the coupling efficiency of parametric downconversion light
(PDC) into single and multi-mode optical fibers as a function of the pump beam
diameter, crystal length and walk-off. We outline two different theoretical
models for the preparation and collection of either single-mode or multi-mode
PDC light (defined by, for instance, multi-mode fibers or apertures,
corresponding to bucket detection). Moreover, we define the mode-matching
collection efficiency, important for realizing a single-photon source based on
PDC output into a well-defined single spatial mode. We also define a multimode
collection efficiency that is useful for single-photon detector calibration
applications.Comment: 13 pages, 12 figure
Resolution and sensitivity of a Fabry-Perot interferometer with a photon-number-resolving detector
With photon-number resolving detectors, we show compression of interference
fringes with increasing photon numbers for a Fabry-Perot interferometer. This
feature provides a higher precision in determining the position of the
interference maxima compared to a classical detection strategy. We also
theoretically show supersensitivity if N-photon states are sent into the
interferometer and a photon-number resolving measurement is performed.Comment: 8 pages, 12 figures, 1 table, minor extensions, title changed, new
figures added, reference correcte
Experimental Test of an Event-Based Corpuscular Model Modification as an Alternative to Quantum Mechanics
We present the first experimental test that distinguishes between an
event-based corpuscular model (EBCM) [H. De Raedt et al.: J. Comput. Theor.
Nanosci. 8 (2011) 1052] of the interaction of photons with matter and quantum
mechanics. The test looks at the interference that results as a single photon
passes through a Mach-Zehnder interferometer [H. De Raedt et al.: J. Phys. Soc.
Jpn. 74 (2005) 16]. The experimental results, obtained with a low-noise
single-photon source [G. Brida et al.: Opt. Expr. 19 (2011) 1484], agree with
the predictions of standard quantum mechanics with a reduced of 0.98
and falsify the EBCM with a reduced of greater than 20
A throughput optimal scheduling policy for a quantum switch
We study a quantum switch that creates shared end-to-end entangled quantum states to multiple sets of users that are connected to it. Each user is connected to the switch via an optical link across which bipartite Bell-state entangled states are generated in each time-slot with certain probabilities, and the switch merges entanglements of links to create end-to-end entanglements for users. One qubit of an entanglement of a link is stored at the switch and the other qubit of the entanglement is stored at the user corresponding to the link. Assuming that qubits of entanglements of links decipher after one time-slot, we characterize the capacity region, which is defined as the set of arrival rates of requests for end-to-end entanglements for which there exists a scheduling policy that stabilizes the switch. We propose a Max-Weight scheduling policy and show that it stabilizes the switch for all arrival rates that lie in the capacity region. We also provide numerical results to support our analysis
Improved implementation of nonclassicality test for a single particle
Recently a test of nonclassicality for a single qubit was proposed [R. Alicki
and N. Van Ryn, J. Phys. A: Math. Theor. 41, 062001 (2008)]. We present an
optimized experimental realization of this test leading to a 46 standard
deviation violation of classicality. This factor of 5 improvement over our
previous result was achieved by moving from the infrared to the visible where
we can take advantage of higher efficiency and lower noise photon detectors.Comment: 4 pages, 1 figur
Experimental Bounds on Classical Random Field Theories
Alternative theories to quantum mechanics motivate important fundamental
tests of our understanding and descriptions of the smallest physical systems.
Here, using spontaneous parametric downconversion as a heralded single-photon
source, we place experimental limits on a class of alternative theories,
consisting of classical field theories which result in power-dependent
normalized correlation functions. In addition, we compare our results with
standard quantum mechanical interpretations of our spontaneous parametric
downconversion source over an order of magnitude in intensity. Our data match
the quantum mechanical expectations, and do not show a statistically
significant dependence on power, limiting on quantum mechanics alternatives
which require power-dependent autocorrelation functions.Comment: 11pages, 2 figure