Condition of Formation of Interference Pattern by Double Slit

Itamar Vidal Silva de Lima

In this thesis we investigate, experimentally and theoretically, many classical and quantum coherence effects of the light. Initially we investigate the interference patterns formation by nonlocal double slit using classical light sources and comparing the results with those using a twin photos light source generated by Spontaneous Parametric Down Conversion (SPDC). We demonstrate that the classical correlation in wave vectors, in beam splitter outs, is a sufficient condition to the interference pattern to exist. In this work we also investigate experimentally the influence of polarized nonlocal double slit and local double slit. Here is present a alternative Fano based interpretation to explain the reason why the polarization of correlated beam has not influence on pattern fringes. We presented also an investigation about the light source parameters influence on the ghost interference interference. We demonstrate experimentally the relationship between, the coherence and source size, and fringes visibility. We extended the concept of complementarity related to coherence and correlation using the changes of the reference beam coherence and observing it’s influence on the interference patterns of the local double slit. In near-field limit, we investigate the existence of conditionality in the wave vector limited by the aperture of objects placed on the classically correlated beams paths. We demonstrate that is possible to find conditionality between the light emitted through the slits apertures. All these experiments performed using the Brown Twiss intensity interferometer (HBT) served to investigate the difference between the transversal effects with quantum and classical incoherent light. Finally, we demonstrate the first experimental measurement demonstrating the polarization changes on the partially coherent light propagation induced by the coherence source changes. This phenomenom was investigated for the free space propagation and for a nonlinear medium modeled by a Kerr medium.

John Kellock Robertson

Itamar Vidal, D. P. Caetano, C. Olindo +2 more

We experimentally investigate interference pattern formation in second-order intensity correlation considering the polarization state of pseudothermal light beams. By placing a double slit in one of the beams it is shown that the interference pattern depends on the polarization state of the light after the slits. When different parts of the double slit are aligned in different beams, we found that the interference is always observed, even for the case where the beams are orthogonally polarized. Our results are analyzed using a filtering process and indistinguishability of paths interpretation. Extensions of our findings to massive particles are also discussed.

E. L. Cleveland

Xia Ruhuai

Abstract Light waves, which have almost no physical properties, are an abstract mathematical concept rather than an objective description. Confused by a set of dark and bright stripes and a sketchy schematic with little relation to the actual result, the double-slit phenomenon was misjudged as being caused by interfering light waves, but this plausible principle implies disastrous flaws. For example, (1) immediately after light passes through the double-slit device, the pattern is generated early or before interference. By changing the device-screen distance, the pattern only scales synchronously without being reconstructed by interference. The pattern with more interference points is darker, but it should be brighter. (2) Light waves can not only be subdivided into many parts but also greatly proliferate. (3) Light waves with missing leading edges outside the screen can still induce much interference. (4) Reflected light waves do not interfere. (5) The effect of polarization direction on interference should not be ignored. (6) Compared with the mathematical model, the location where the dark stripe should appear is actually the brightest spot. The formation principle of multiple regular dark stripes cannot be found. (7) To reflect the quantum property in the interference process, unless all conditions are simultaneously met, interference will not be triggered, and therefore, the principle of interference will be rejected. (8) A light source cannot be produced in a slit that may be in vacuum. (9) In the causality test, to verify the effect of collapse, the photons that have collapsed into particles should be tested again with a double-slit test. (10) The phenomenon of "observed tampering results" is obtained by observation. Has it been tampered with by observation? (11) If light is a wave, then matter and antimatter are conjoined. In conclusion, Newton's particle model is wrong, as is light wave theory.

Natalie G. Ferris