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This paper presents the research and development of two terahertz imaging systems based on photonic and electronic principles, respectively. As part of this study, a survey of ongoing research in the field of terahertz imaging is provided focusing on security applications. Existing terahertz imaging systems are reviewed in terms of the employed architecture and data processing strategies. Active multichannel measurement method is found to be promising for real-time applications among the various terahertz imaging techniques and is chosen as a basis for the imaging instruments presented in this paper. An active system operation allows for a wide dynamic range, which is important for image quality. The described instruments employ a multichannel high-sensitivity heterodyne architecture and aperture filling techniques, with close to real-time image acquisition time. In the case of the photonic imaging system, mechanical scanning is completely obsolete. We show 2-D images of simulated 3-D image data for both systems. The reconstruction algorithms are suitable for 3-D real-time operation, only limited by mechanical scanning.

A long-standing goal in the quantum information community has been to realize quantum networks between distant sites. In this tutorial we describe the experimental demonstration of three crucial components in such a network using the off-resonant Faraday interaction between macroscopic atomic ensembles and coherent light. These are the realization of (a) deterministic entanglement between atomic samples in separate environments, (b) quantum mapping of an unknown light state into an atomic memory and (c) disembodied transport of states between quantum nodes via light–atom teleportation.

Derivation of P. micra from P. wilcoxensis during middle Eocene by gradual compression of test, reduction in test size in late Eocene-early Oligocene (P. micra P. cf. naguewichiensis)