Light field

About: Light field is a research topic. Over the lifetime, 5357 publications have been published within this topic receiving 87424 citations.

Observation of squeezed light from one atom excited with two photons

Abstract: The light field emitted by a single atom can exhibit non-classical effects such as 'squeezing', which is characterized by sub-shot noise amplitude or phase fluctuations. This phenomenon was predicted 30 years ago, but has been observed experimentally only for macroscopic and mesoscopic media down to a few tens of atoms. Ourjoumtsev et al. now report the observation of squeezed light generated from a single atom excited by laser light in a high-finesse optical resonator. In contrast to the emission of single photons, a more easily observed event, the squeezed light derives from the quantum coherence of photon pairs emitted from the system. This may offer new perspectives for photonic quantum logic with single emitters. Single quantum emitters such as atoms are well known as non-classical light sources with reduced noise in the intensity, capable of producing photons one by one at given times1. However, the light field emitted by a single atom can exhibit much richer dynamics. A prominent example2,3 is the predicted ability of a single atom to produce quadrature-squeezed light4, which has fluctuations of amplitude or phase that are below the shot-noise level. However, such squeezing is much more difficult to observe than the emission of single photons5. Squeezed beams have been generated using macroscopic and mesoscopic media down to a few tens of atoms6, but despite experimental efforts7,8,9, single-atom squeezing has so far escaped observation. Here we generate squeezed light with a single atom in a high-finesse optical resonator. The strong coupling of the atom to the cavity field induces a genuine quantum mechanical nonlinearity10, which is several orders of magnitude larger than in typical macroscopic media11,12,13. This produces observable quadrature squeezing14,15,16, with an excitation beam containing on average only two photons per system lifetime. In sharp contrast to the emission of single photons17, the squeezed light stems from the quantum coherence of photon pairs emitted from the system18. The ability of a single atom to induce strong coherent interactions between propagating photons opens up new perspectives for photonic quantum logic with single emitters19,20,21,22,23,24.

Comparison and Evaluation of Light Field Image Coding Approaches

Abstract: The recent advances in light field imaging, supported among others by the introduction of commercially available cameras, e.g., Lytro or Raytrix, are changing the ways in which visual content is captured and processed. Efficient storage and delivery systems for light field images must rely on compression algorithms. Several methods to compress light field images have been proposed recently. However, in-depth evaluations of compression algorithms have rarely been reported. This paper aims at the evaluation of perceived visual quality of light field images and at comparing the performance of a few state-of-the-art algorithms for light field image compression. First, a processing chain for light field image compression and decompression is defined for two typical use cases, professional and consumer. Then, five light field compression algorithms are compared by means of a set of objective and subjective quality assessments. An interactive methodology recently introduced by authors, as well as a passive methodology is used to perform these evaluations. The results provide a useful benchmark for future development of compression solutions for light field images.

Nonlinear optical lithography with ultra-high sub-Rayleigh resolution.

Abstract: A nonlinear optical, interferometric method for improving the resolution of a lithographic system by an arbitrarily large factor with high visibility is described. The technique is implemented experimentally for both two-fold and three-fold enhancement of the resolution with respect to the traditional Rayleigh limit. In these experiments, an N-photon-absorption recording medium is simulated by Nth harmonic generation followed by a CCD camera. This technique does not exploit quantum features of light; this fact suggests that the improved resolution achieved through use of “quantum lithography” results primarily from the nonlinear response of the recording medium and not from quantum features of the light field.

Light Field Display Device and Method

Abstract: The present invention provides a light field display device ( 300 ) comprising an array of light field display elements ( 310 ) populating a display surface, each display element ( 310 ) comprising: a beam generator ( 522 ) for generating an output beam of light; a radiance modulator ( 524 ) for modulating the radiance of the beam over time; a focus modulator ( 530 ) for modulating the focus of the beam over time; and a scanner ( 504, 506 ) for scanning the beam across a two-dimensional angular field.

Atom localization and center-of-mass wave-function determination via multiple simultaneous quadrature measurements

Abstract: We discuss localization and center-of-mass wave-function measurement of a quantum particle using multiple simultaneous dispersive interactions of the particle with different standing-wave fields. In particular, we consider objects with an internal structure consisting of a single ground state and several excited states. The transitions between ground and the corresponding excited states are coupled to the light fields in the dispersive limit, thus giving rise to a phase shift of the light field during the interaction. We show that multiple simultaneous measurements allow both an increase in the measurement or localization precision in a single direction and the performance of multidimensional measurements or localization. Further, we show that multiple measurements may relax the experimental requirements for each individual measurement.