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The existence of coronal plasmoids has been postulated for many years in order to supply material to streamers and possibly to the solar wind (SW). The W-L SoHO C2 Lasco coronagraph observations were made under the 2.2 solar radii (R0) occulting disk to look at the ultimate sources of the SW; EUV imagers are preferably devoted to the analysis of the corona on and very near the solar disk. Here, in addition to eclipse white-light (W-L) snapshots, we used the new SWAP space-borne imager designed for the systematic survey of coronal activity in the EUV lines near 17.4 nm, over a field of view (FOV) up to 2 R0. Using summed and co-aligned images, the corona can then be evaluated for the 1st time up to the limit of this FOV. At the time of the July 11, 2010, solar total eclipse a 20h continuous run of observations was collected, including images taken during eclipse totality from several ground observing locations where W-L data were collected. A plasmoid-like off-limb event was followed using the SWAP summed

Solar eclipse observations have long suggested that the white-light corona is permeated by long fine rays. By comparing photographs of the 2006 March 29 total eclipse with current-free extrapolations of photospheric field measurements and with images from the Solar and Heliospheric Observatory (SOHO), we deduce that the bulk of these linear features fall into three categories: (1) polar and low-latitude plumes that overlie small magnetic bipoles inside coronal holes, (2) helmet streamer rays that overlie large loop arcades and separate coronal holes of opposite polarity, and (3) pseudostreamer rays that overlie twin loop arcades and separate coronal holes of the same polarity. The helmet streamer rays extend outward to form the plasma sheet component of the slow solar wind, while the plumes and pseudostreamers contribute to the fast solar wind. In all three cases, the rays are formed by magnetic reconnection between closed coronal loops and adjacent open field lines. Although seemingly ubiquitous when seen projected against the sky plane, the rays are in fact rooted inside or along the boundaries of coronal holes.

The general objective of this presentation is to demonstrate the great potential of III-V semiconductor -membrane photonic devices, with a special emphasis on InP and related materials in the prospect of new developments in the field of micro-nano-photonics. Various classes devices will be presented, which will have the communality of being based on the use of high index contrast structuration of semiconductor materials. The structuration is achieved vertically for the first class, by forming thin semiconductor membranes surrounded by low optical index material, or laterally for the second class via a two-dimensional (2-D) lateral structuration of the membranes (thus, resulting in 2-D photonic crystal (PC) structures); both structurations are also combined, according to a "2.5-dimensional" approach, which should broaden considerably the combinations of functionality beyond those presently contemplated with the two first classes. The general technological scheme of the membrane approach is fully compatible with planar technology which is widely in use in the world of silicon microelectronics and with heterogeneous integration of III-V active microphotonic devices with silicon microphotonics and microelectronics (e.g., molecular bonding of InP active membranes on silica on silicon substrate). A variety of devices will be presented, featuring micro-lasers based on 2-D PC micro-cavities as well as on 2-D Bloch modes (2-D distributed-feed-back micro-laser) for in plane and surface emission.

One- and two-dimensional photonic crystal slabs have numerous applications in integrated optics. Unfortunately, due to their finite height, their in-plane guided modes can suffer outcoupling losses. Although considered as detrimental in the context of the development of photonic integrated circuits, it turns that the coupling of waveguided modes to radiative modes can be usefully exploited for the manipulation of photons in free space. It is shown in this paper that interaction of radiative and guided modes through a photonic crystal, especially under conditions where the latter correspond to extrema of the dispersion characteristics of the photonic crystal, results in resonance phenomena, which can be used practically for the development of new classes of devices, e.g., combining photonic crystal and microoptoelectromechanical systems structures.

One dimensional and two dimensional photonic crystal slabs have numerous applications in integrated optics. Unfortunately, due to their finite height, their in plane guided modes can suffer out-coupling losses. Although considered as detrimental in the context of the development of photonic integrated circuits, it turns that the coupling of wave-guided modes to radiative modes can be usefully exploited for the manipulation of photons in free space. It is shown in this paper that interaction of radiative and guided modes through a photonic crystal, especially under conditions where the later correspond to extreme of the dispersion characteristics of the photonic crystal, results in resonance phenomena which can be used practically for the development of new classes of devices, e.g. combining photonic crystal and MOEMS (micro opto electro mechanical systems) structures: PCMOEMS.

We report the direct, room-temperature, near-field mapping and spectroscopy of the optical modes of a photonic-crystal microcavity containing quantum wells. We use a near-field optical probe to reveal the imprint of the cavity mode structure on the quantum-well emission. Furthermore, near-field spectroscopy allows us to demonstrate the strong spatial and spectral dependence of the coupling between the sources and the microcavity. This knowledge will be essential in devising future nanophotonic devices. © 2005 The American Physical Society.

The general objective of this presentation is to demonstrate the great potential of two dimensional (2D) Photonic Crystals (PC) based on InP-membranes bonded onto silica on silicon substrates, with a special emphasis on the development of various classes of 2D PC microlasers. The basic building block consists in an InP (and related material) membrane including a 2D PC formed by a lattice of holes : the membrane is bonded onto low index material, e .g. silica on silicon substrate, in the prospect of heterogeneous integration with silicon based microelectronics. Examples of devices will be presented, specifically micro-lasers based on 2D PC micro-cavities as well as on 2D in plane and surface emitting Bloch modes (2D Distributed-Feed-Back micro-laser).

New types of switching devices with spatial and spectral resolution combining photonic crystal (PC) and micro-opto-electro-mechanical structures (MOEMS) are proposed. They are based on multilayer suspended high refractive index III–V-based semiconductor membranes, some of these membranes being laterally structured to form a bidimensional PC. We present a method for fabricating these devices implying an original approach that combines micro- and nanotechnologies. The PC is patterned by using electron beam lithography and reactive ion etching. The MOEMS structure is an InP-air gaps multilayer realized by a combination of classical processing of epitaxially grown layers with a selective postprocess micromachining of sacrificial epilayers. Primary demonstrator acting as a wavelength selective and “switchable” coupler including a triangular lattice of PC holes on top of a InP–air gap pair-based Bragg reflector has been realized. We present the preliminary results on the technological fabrication and optical ch...

Graphite-lattice photonic crystal structures in InP-based heterostructures transferred onto silicon, including a multi-quantum well active layer, have been designed and fabricated. 1.5 /spl mu/m vertical emission laser operation was observed at room temperature, with very low threshold (below 50 /spl mu/W).