Shimony, AbnerJaeger, Gregg2017-09-252017-09-251994-05-01A Shimony, G Jaeger. 1994. "Complementarity and path distinguishability: Some recent results concerning photon pairs." NASA, Goddard Space Flight Center, International workshop on squeezed states and uncertainty relations 3, (Baltimore, 1993), 523 (1994).nasa:19950007548https://hdl.handle.net/2144/24004Two results concerning photon pairs, one previously reported and one new, are summarized. It was previously shown that if the two photons are prepared in a quantum state formed from bar-A and bar-A' for photon 1 and bar-B and bar-B' for photon 2, then both one- and two-particle interferometry can be studied. If upsilon(sub i) is the visibility of one-photon interference fringes (i = 1,2) and upsilon(sub 12) is the visibility of two-photon fringes (a concept which we explicitly define), then upsilon(sub i) squared + upsilon(sub 12) squared is less than or equal to 1. The second result concerns the distinguishability of the paths of photon 2, using the known 2-photon state. A proposed measure E for path distinguishability is based upon finding an optimum strategy for betting on the outcome of a path measurement. Mandel has also proposed a measure of distinguishability P(sub D), defined in terms of the density operator rho of photon 2. We show that E is greater than or equal to P(sub D) and that upsilon(sub 2) = (1 - E(exp 2))exp 1/2.No CopyrightAtomic & molecular physicsPhotonsQuantum mechanicsPhoton beamsParadoxesInterferometryInterferenceConference materials0000-0002-5725-6491 (Jaeger, G)