3 research outputs found
Entangled photon apparatus for the undergraduate laboratory
We present detailed instructions for constructing and operating an apparatus
to produce and detect polarization-entangled photons. The source operates by
type-I spontaneous parametric downconversion in a two-crystal geometry. Photons
are detected in coincidence by single-photon counting modules and show strong
angular and polarization correlations. We observe more than 100 entangled
photon pairs per second. A test of a Bell inequality can be performed in an
afternoon.Comment: 6 pages, 9 figure
Entangled photons, nonlocality and Bell inequalities in the undergraduate laboratory
We use polarization-entangled photon pairs to demonstrate quantum nonlocality
in an experiment suitable for advanced undergraduates. The photons are produced
by spontaneous parametric downconversion using a violet diode laser and two
nonlinear crystals. The polarization state of the photons is tunable. Using an
entangled state analogous to that described in the Einstein-Podolsky-Rosen
``paradox,'' we demonstrate strong polarization correlations of the entanged
photons. Bell's idea of a hidden variable theory is presented by way of an
example and compared to the quantum prediction. A test of the Clauser, Horne,
Shimony and Holt version of the Bell inequality finds , in
clear contradiciton of hidden variable theories. The experiments described can
be performed in an afternoon.Comment: 10 pages, 6 figure