Light field

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

Squeezing and entanglement delay using slow light

Abstract: We examine the interaction of a weak probe with N atoms in a Lambda-level configuration under the conditions of electromagnetically induced transparency (EIT). In contrast to previous works on EIT, we calculate the output state of the resultant slowly propagating light field while taking into account the effects of ground state dephasing and atomic noise for a more realistic model. In particular, we propose two experiments using slow light with a nonclassical probe field and show that two properties of the probe, entanglement and squeezing, characterizing the quantum state of the probe field, can be well-preserved throughout the passage.

Chapter 9 – Stimulated Brillouin and Stimulated Rayleigh Scattering

Abstract: Publisher Summary A light scattering process is said to be stimulated if the fluctuations are induced by the presence of the light field. Stimulated light scattering is typically very much more efficient than spontaneous light scattering. Stimulated Brillouin scattering (SBS) process leads to amplification of a Stokes wave propagating in any direction except for the propagation direction of the laser wave. However, SBS is usually observed only in the backwards direction, because the spatial overlap of the laser and Stokes beams is largest under these conditions. Electrostriction is also important both as a mechanism leading to a third-order nonlinear optical response and as a coupling mechanism that leads to stimulated Brillouin scattering. The scattering of light from isobaric density fluctuations that are driven by the process of electrostriction leads to electrostrictive stimulated Rayleigh scattering, whereas the scattering of light from isobaric density fluctuations that are driven by the process of optical absorption leads to thermal stimulated Rayleigh scattering.

Maxwell-Bloch equations for spatially inhomogeneous semiconductor lasers. II. Spatiotemporal dynamics

Abstract: The spatiotemporal dynamics of broad-area lasers is analyzed on the basis of a space- and momentum-dependent density-matrix approach. To this means the space-dependent Maxwell-Bloch equations for the semiconductor laser (derived in our preceding paper I) are solved by direct numerical integration. The space and momentum resolved dynamics of the active semiconductor medium, described by microscopic charge-carrier distributions and nonlinear polarization functions, are treated self-consistently with the spatiotemporal dynamics of the light field. Carrier transport dynamics are approximated on the basis of an ambipolar diffusion approximation consistent with the microscopic processes. Boundary-influenced macroscopic waveguiding properties of typical conventional as well as tapered broad-area laser cavities are taken into account. The dynamics of the formation and longitudinal propagation of unstable transverse optical filamentary structures are analyzed. Simultaneous spectral and spatial hole burning with dynamical spatiospectral variations on ultrashort (ps and sub-ps) time scales are observed in the charge-carrier distributions, reflecting the interplay between stimulated emission and the relaxation dynamics of the carrier distributions as well as the polarization. The transverse hole burning leads to complex spatiotemporal patterns in the macroscopic intensity picture with different optical frequencies associated with various locations of the modelike near-field patterns. \textcopyright{} 1996 The American Physical Society.

Digital Correction of Lens Aberrations In Light Field Photography

Abstract: Digital light field photography consists of recording the radiance along all rays (the 4D light field) flowing into the image plane inside the camera, and using the computer to control the final convergence of rays in final images. The light field is sampled with integral photography techniques, using a microlens array in front of the sensor inside a conventional digital camera. Previous work has shown that this approach enables refocusing of photographs after the fact. This paper explores computation of photographs with reduced lens aberrations by digitally re-sorting aberrated rays to where they should have terminated. The paper presents a test with a prototype light field camera, and simulated results across a set of 35mm format lenses.

Cavity QED effects in semiconductor microcavities

Abstract: A theoretical investigation of cavity QED effects in semiconductor microcavities containing quantum wells is presented. A model Hamiltonian is used to derive equations of motion for the quantum photon and exciton fields in the cavity. Quantum effects such as squeezing and antibunching are predicted in the light field going out of the cavity under irradiation by a coherent laser field, if exciton-phonon scattering is weak enough. Exciton-phonon scattering is shown to destroy the nonclassical effects and to yield excess noise in the output field.