NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Due to the lapse in federal government funding, NASA is not updating this website. We sincerely regret this inconvenience.

Back to Results
A loophole-free Bell's inequality experimentThe proof of Nature's nonlocality through Bell-type experiments is a topic of longstanding interest. Nevertheless, no experiments performed thus far have avoided the so-called 'detection loophole,' arising from low detector efficiencies and angular-correlation difficulties. In fact, most, if not all, of the systems employed to date can never close this loophole, even with perfect detectors. In addition, another loophole involving the non-rapid, non-random switching of various parameter settings exists in all past experiments. We discuss a proposal for a potentially loophole-free Bell's inequality experiment. The source of the EPR-correlated pairs consists of two simultaneously-pumped type-2 phase-matched nonlinear crystals and a polarizing beam splitter. The feasibility of such a scheme with current detector technology seems high, and will be discussed. We also present a single-crystal version, motivated by other work presented at this conference. In a separate experiment, we have measured the absolute detection efficiency and time response of four single-photon detectors. The highest observed efficiencies were 70.7 plus or minus 1.9 percent (at 633 nm, with a device from Rockwell International) and 76.4 plus or minus 2.3 percent (at 702 nm, with an EG&G counting module). Possible efficiencies as high as 90 percent were implied. The EG&G devices displayed sub-nanosecond time resolution.
Document ID
19950007555
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Kwiat, Paul G.
(California Univ. Berkeley, CA, United States)
Steinberg, Aephraim M.
(California Univ. Berkeley, CA, United States)
Chiao, Raymond Y.
(California Univ. Berkeley, CA, United States)
Eberhard, Philippe H.
(California Univ. Berkeley, CA, United States)
Date Acquired
September 6, 2013
Publication Date
May 1, 1994
Publication Information
Publication: NASA. Goddard Space Flight Center, Third International Workshop on Squeezed States and Uncertainty Relations
Subject Category
Thermodynamics And Statistical Physics
Accession Number
95N13968
Funding Number(s)
CONTRACT_GRANT: N00014-90-J-1259
CONTRACT_GRANT: DE-AC03-76SF-00098
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available