All-fiber three-path Mach-Zehnder interferometer.
We report the realization of a three-path Mach-Zehnder interferometer using single-mode fibers and two integrated 3 x 3 fiber couplers. We observed enhanced phase sensitivity, as compared with two-path interferometers, with a visibility of the interference pattern of more than 97%. This interferometer has an analog in two-photon interferometry, and we believe it to be the first nontrivial example of N x N multiport interferometers.
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G
Weihs
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M
Reck
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H
Weinfurter
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A
Zeilinger