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Progress in correlated optics

Kai Wang

Published Jan 1, 2008• 0 citations
OpenAlex

Abstract

We discuss in brief some interesting optical experiments based on intensity correlation measurement,such as ghost imaging,ghost interference,sub-wavelength interference and nonlocal double-slit interference,performed with both entangled two-photon states generated by spontaneous parametric down-conversion,and with thermal light.Some debates in this topic are also mentioned.

Related papers

Observation of Two-Photon “Ghost” Interference and Diffraction

Dmitry Strekalov, Alexander V. Sergienko, Давид Николаевич Клышко +1 more

Observations of unusual diffraction and interference by two-photon correlation measurements are reported. The signal and idler beams produced by spontaneous parametric down-conversion are sent in different directions, and detected by two distant pointlike photon counting detectors. A double slit or a single slit is inserted into the signal beam. Interference-diffraction patterns are observed in coincidences by scanning the detector in the idler beam.

Physical Review Letters•May 1, 1995•890 citations

The Physics of Ghost Imaging

Yanhua H. Shih

One of the most surprising consequences of quantum mechanics is the nonlocal multi-particle interference observable in joint-detection of distant particle-detectors. Ghost imaging is one of such phenomena. Two types of ghost imaging have been experimentally demonstrated since 1995. Type-one ghost imaging uses entangled photon pairs as the light source. The nonlocal point-to-point image-forming correlation is the result of a constructive-destructive superposition among a large number of biphoton amplitudes, a nonclassical entity corresponding to different yet indistinguishable alternative ways of producing a joint-detction event between distant photodetectors. Type-two ghost imaging uses chaotic-thermal light. The type-two image-forming correlation is the result of interferences between paired two-photon amplitudes, corresponding to two different yet indistinguishable alternative ways of triggering a join-detection event by two independent photons. A great deal of confusion about ghost imaging comes from "ghost shadow". Similar to x-ray photography, a ghost shadow can be made in coincidences by "blocking-partial blocking-unblocking" of either co-rotating laser beams or classically correlated "speckles". "Ghost shadow" is indeed a classical phenomenon. The physics of ghost imaging, however, is fundamentally different. This article is aimed at exploring the nonlocal two-photon interference nature of ghost imaging.

arXiv:0805.1166•May 7, 2008•1 citation

Two-photon double-slit interference experiment

C. K. Hong, Tae-Gon Noh

We report a two-photon double-slit interference experiment. Two correlated photons, generated by spontaneous parametric downconversion and traveling in different directions, are made to pass through a double slit in such a way that the path of one photon can be identified with that of the other photon. No single-photon interference pattern is observed even if the path is not actually identified, but a spatial interference pattern appears in the joint detection counting rates of the photon pairs. It can easily be shown that these nonlocal phenomena cannot be exhibited by any kind of classical field.

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Some topics in Quantum Imaging

Luigi A. Lugiato, A. Gatti, E. Brambilla +5 more

Abstract. The field of Quantum Imaging exploits the quantum nature of light and the intrinsic parallelism of optical signals to devise novel techniques for optical imaging and for parallel information processing at the quantum level (see [1] and references quoted therein). In this presentation, we will shortly discuss two topics in this area: the first is the so-called ghost imaging which, however, is not necessarily quantum; the second is the detection of faint amplitude objects with a sensitivity beyond the standard quantum limit, and in this case we are fully in the quantum domain. Both topics are related to the phenomenon of optical parametric down-conversion (PDC), in which a fraction of the pump photons of a laser beam, injected into a crystal with a quadratic non-linearity, are down-converted to a pair of signal and idler photons, with conservation of total energy and total momentum. A feature of paramount importance is that the signal and idler beams are spatially correlated both in the near field (position correlation) and in the far field (momentum correlation).The simultaneous presence of position and momentum correlation implies quantum entanglement, as it has been also observed experimentally [2]. 1. Ghost Imaging

Journal of Physics Conference Series•Feb 1, 2010•0 citations

The physics of ghost imaging

Yanhua H. Shih

One of the most surprising consequences of quantum mechanics is the nonlocal behavior of a multi-particle system. Although questions regarding fundamental issues of quantum theory still exist, nonclassical surprises have started to play important roles in practical applications. Ghost imaging is one of these exciting areas. Two types of ghost imaging have been experimentally demonstrated since 1995. Type-one ghost imaging uses entangled photon pairs and type-two ghost imaging uses chaotic light. The unique point-to-point image-forming correlation between the object and image planes in ghost imaging is the result of a constructive-destructive interference which involves the nonlocal superposition of two-photon amplitudes, a nonclassical entity corresponding to different yet indistinguishable alternative ways of triggering a joint-detection event. This talk will explore and analyze the quantum nature of ghost imaging. It is true that classical challenges have never stopped. Quantum? Classical? A hot debate is currently focused on ghost imaging. This talk will defend the quantum mechanical point of view.

International Conference on Quantum Information•Jan 1, 2008•13 citations

Spatial coherence and entanglement of light

H. Di Lorenzo Pires

In this thesis we investigate diverse aspects of spatial coherence of light. Non-classical fields containing two photons can be generated by a nonlinear optical process known as spontaneous parametric down conversion (SPDC). Among the questions we consider are: What is so special about spatial entanglement? How is it revealed in the fourth-order correlations? What are the differences between a highly entangled and a classically correlated state? How can the number of modes be manipulated and measured? For a two-photon system, we measure both intensities and two-photon correlations. To get deeper insights into how coherence affects interference, we also investigate completely classical sources.

•Sep 13, 2011•0 citations
We discuss in brief some interesting optical experiments based on intensity correlation measurement,such as ghost imaging,ghost interference,sub-wavelength interference and nonlocal double-slit interference,performed with both entangled two-photon states generated by spontaneous parametric down-conversion,and with thermal light.Some debates in this topic are also mentioned.
One of the most surprising consequences of quantum mechanics is the nonlocal multi-particle interference observable in joint-detection of distant particle-detectors. Ghost imaging is one of such phenomena. Two types of ghost imaging have been experimentally demonstrated since 1995. Type-one ghost imaging uses entangled photon pairs as the light source. The nonlocal point-to-point image-forming correlation is the result of a constructive-destructive superposition among a large number of biphoton amplitudes, a nonclassical entity corresponding to different yet indistinguishable alternative ways of producing a joint-detction event between distant photodetectors. Type-two ghost imaging uses chaotic-thermal light. The type-two image-forming correlation is the result of interferences between paired two-photon amplitudes, corresponding to two different yet indistinguishable alternative ways of triggering a join-detection event by two independent photons. A great deal of confusion about ghost imaging comes from "ghost shadow". Similar to x-ray photography, a ghost shadow can be made in coincidences by "blocking-partial blocking-unblocking" of either co-rotating laser beams or classically correlated "speckles". "Ghost shadow" is indeed a classical phenomenon. The physics of ghost imaging, however, is fundamentally different. This article is aimed at exploring the nonlocal two-photon interference nature of ghost imaging.
We report a two-photon double-slit interference experiment. Two correlated photons, generated by spontaneous parametric downconversion and traveling in different directions, are made to pass through a double slit in such a way that the path of one photon can be identified with that of the other photon. No single-photon interference pattern is observed even if the path is not actually identified, but a spatial interference pattern appears in the joint detection counting rates of the photon pairs. It can easily be shown that these nonlocal phenomena cannot be exhibited by any kind of classical field.
Abstract. The field of Quantum Imaging exploits the quantum nature of light and the intrinsic parallelism of optical signals to devise novel techniques for optical imaging and for parallel information processing at the quantum level (see [1] and references quoted therein). In this presentation, we will shortly discuss two topics in this area: the first is the so-called ghost imaging which, however, is not necessarily quantum; the second is the detection of faint amplitude objects with a sensitivity beyond the standard quantum limit, and in this case we are fully in the quantum domain. Both topics are related to the phenomenon of optical parametric down-conversion (PDC), in which a fraction of the pump photons of a laser beam, injected into a crystal with a quadratic non-linearity, are down-converted to a pair of signal and idler photons, with conservation of total energy and total momentum. A feature of paramount importance is that the signal and idler beams are spatially correlated both in the near field (position correlation) and in the far field (momentum correlation).The simultaneous presence of position and momentum correlation implies quantum entanglement, as it has been also observed experimentally [2]. 1. Ghost Imaging
One of the most surprising consequences of quantum mechanics is the nonlocal behavior of a multi-particle system. Although questions regarding fundamental issues of quantum theory still exist, nonclassical surprises have started to play important roles in practical applications. Ghost imaging is one of these exciting areas. Two types of ghost imaging have been experimentally demonstrated since 1995. Type-one ghost imaging uses entangled photon pairs and type-two ghost imaging uses chaotic light. The unique point-to-point image-forming correlation between the object and image planes in ghost imaging is the result of a constructive-destructive interference which involves the nonlocal superposition of two-photon amplitudes, a nonclassical entity corresponding to different yet indistinguishable alternative ways of triggering a joint-detection event. This talk will explore and analyze the quantum nature of ghost imaging. It is true that classical challenges have never stopped. Quantum? Classical? A hot debate is currently focused on ghost imaging. This talk will defend the quantum mechanical point of view.
In this thesis we investigate diverse aspects of spatial coherence of light. Non-classical fields containing two photons can be generated by a nonlinear optical process known as spontaneous parametric down conversion (SPDC). Among the questions we consider are: What is so special about spatial entanglement? How is it revealed in the fourth-order correlations? What are the differences between a highly entangled and a classically correlated state? How can the number of modes be manipulated and measured? For a two-photon system, we measure both intensities and two-photon correlations. To get deeper insights into how coherence affects interference, we also investigate completely classical sources.