Using recently collected current and hydrographic data, we provide a high resolution picture of the subinertial flow and estimate the volume transport through the Luzon Strait. The distribution of the subinertial flow shows a strong westward flow around 100 m in the northern part of the Luzon Strait, while the eastward flow is confined to the deeper layers, mostly at depths around 1000 m. The total volume transport is estimated to be 6 ± 3 Sv during the period of observations from October 4 to 16, 2005. The observations also confirm that the Luzon Strait transport has a sandwiched vertical structure. The net westward volume transport in the deep (>1500 m) layer of the Luzon Strait reaches 2 Sv.

From drug delivery to chemical and biological catalysis and cosmetics, the need for efficient fabrication pathways for particles over a wide range of sizes, from a variety of materials, and in many different structures has been well established. Here we harness the inherent scalability of fibre production and an in-fibre Plateau-Rayleigh capillary instability for the fabrication of uniformly sized, structured spherical particles spanning an exceptionally wide range of sizes: from 2 mm down to 20 nm. Thermal processing of a multimaterial fibre controllably induces the instability, resulting in a well-ordered, oriented emulsion in three dimensions. The fibre core and cladding correspond to the dispersed and continuous phases, respectively, and are both frozen in situ on cooling, after which the particles are released when needed. By arranging a variety of structures and materials in a macroscopic scaled-up model of the fibre, we produce composite, structured, spherical particles, such as core-shell particles, two-compartment 'Janus' particles, and multi-sectioned 'beach ball' particles. Moreover, producing fibres with a high density of cores allows for an unprecedented level of parallelization. In principle, 10(8) 50-nm cores may be embedded in metres-long, 1-mm-diameter fibre, which can be induced to break up simultaneously throughout its length, into uniformly sized, structured spheres.

We present a technique for large-scale optimization of optical microcavities based on the frequency-averaged local density of states (LDOS), which circumvents computational difficulties posed by previous eigenproblem-based formulations and allows us to perform full topology optimization of three-dimensional (3d) leaky cavity modes. We present theoretical results for both 2d and fully 3d computations in which every pixel of the design pattern is a degree of freedom ("topology optimization"), e.g. for lithographic patterning of dielectric slabs in 3d. More importantly, we argue that such optimization techniques can be applied to design cavities for which (unlike silicon-slab single-mode cavities) hand designs are difficult or unavailable, and in particular we design minimal-volume multi-mode cavities (e.g. for nonlinear frequency-conversion applications).

The ability to produce small scale, crystalline silicon spheres is of significant technological and scientific importance, yet scalable methods for doing so have remained elusive. Here we demonstrate a silicon nanosphere fabrication process based on an optical fibre drawing technique. A silica-cladded silicon-core fibre with diameters down to 340 nm is continuously fed into a flame defining an axial thermal gradient and the continuous formation of spheres whose size is controlled by the feed speed is demonstrated. In particular, spheres of diameter o500 nm smaller than those produced under isothermal heating conditions are shown and analysed. A fibre with dual cores, p-type and n-type silicon, is drawn and processed into spheres. Spatially coherent break-up leads to the joining of the spheres into a bispherical silicon 'p-n molecule'. The resulting device is measured to reveal a rectifying I-V curve consistent with the formation of a p-n junction.

We describe an approach based on topology optimization that enables automatic discovery of wavelengthscale photonic structures for achieving high-efficiency second-harmonic generation (SHG). A key distinction from previous formulation and designs that seek to maximize Purcell factors at individual frequencies is that our method not only aims to achieve frequency matching (across an entire octave) and large radiative lifetimes, but also optimizes the equally important nonlinear-coupling figure of meritβ, involving a complicated spatial overlap-integral between modes. We apply this method to the particular problem of optimizing micropost and grating-slab cavities (one-dimensional multilayered structures) and demonstrate that a variety of material platforms can support modes with the requisite frequencies, large lifetimes Q > 10 4 , small modal volumes ∼ (λ/n) 3 , and extremely largeβ 10 −2 , leading to orders of magnitude enhancements in SHG efficiency compared to state of the art photonic designs. Such giantβ alleviate the need for ultranarrow linewidths and thus pave the way for wavelength-scale SHG devices with faster operating timescales and higher tolerance to fabrication imperfections. AbstractWe review the temporal-coupled mode equations describing second harmonic generation in doubly resonant cavities and motivate the dimensionless nonlinear couplingβ described in Eq. 3 of the main text.We provide further details on the topology optimization formulation for second harmonic generation and describe generalizations to other nonlinear processes. Finally, we present more detailed descriptions of the optimized micropost and gratings cavities.

[1] A pair of mesoscale eddies, namely, an anticyclonic eddy (AE) and a cyclonic eddy (CE), generated southwest of Taiwan was investigated using long-term moored observations augmented with satellite and reanalysis data. AE (CE) increased the upperocean current to 100 cm/s (50 cm/s) and generated temperature anomaly (T 0 ) up to 7.5 C (23.0 C). The vertical structure of AE presented a phase difference between T 0 and velocity, with the core of T 0 located south of the zero-velocity line. This phase difference induced a 228.5 6 12.0 TW (1 TW 5 10 12 W) westward eddy heat transport southwest of Taiwan. AE also presented strong nonlinearity in the upper ocean and yielded an annual mean volume transport of 0.86 6 0.15 Sv. Energy analysis showed that both baroclinic and barotropic instabilities were important for the generation and growth of the eddy pair, and contribution from wind work was relative small. In the deep sea, AE (CE) intensified the deep currents and generated large positive (negative) T 0 . The deep and surface currents flowed in opposite directions during the eddy events, which is consistent with the interpretation that the eddy pair is dominated by the first baroclinic mode. The observed deep-penetrating eddy pair could greatly influence the deep circulation of the northeastern South China Sea.

The nature of light interaction with matter can be dramatically altered in optical cavities, often inducing nonclassical behavior. In solid-state systems, excitons need to be spatially incorporated within nanostructured cavities to achieve such behavior. Although fascinating phenomena have been observed with inorganic nanostructures, the incorporation of organic molecules into the typically inorganic cavity is more challenging. Here, we present a unique optofluidic platform comprising organic molecules in solution suspended on a photonic crystal surface, which supports macroscopic Fano resonances and allows strong and tunable interactions with the molecules anywhere along the surface. We develop a theoretical framework of this system and present a rigorous comparison with experimental measurements, showing dramatic spectral and angular enhancement of emission. We then demonstrate that these enhancement mechanisms enable lasing of only a 100-nm thin layer of diluted solution of organic molecules with substantially reduced threshold intensity, which has important implications for organic light-emitting devices and molecular sensing.fluorescence enhancement | enhanced light-matter interaction O rganic molecules are pervasive in daily life: from natural proteins, to human synthesized fluorescing labels, to organic semiconductors. The interaction of light with such molecules is at the heart of important technological advances in biomolecular detection (1-4), fluorescent microscopy (5), and organic light-emitting devices (6-9), as well as more fundamental studies of cavity quantum electrodynamics (10-12) and various types of enhanced spectroscopy (13) and sensing (14). In all, it is frequently sought to alter (15-18) and often to enhance this interaction by allowing it to occur in a typically nanostructured cavity, where both the lifetime of the resonances and the optical density of states (DOS) (19) can be tailored. However, there are inherent challenges in incorporating organic molecules in such cavities: first, their dissimilar compositional structure makes it difficult to incorporate them within the highdielectric regions of the cavity, where long-lifetime resonances concentrate their electromagnetic energy. Second, micro-and nanostructured cavities typically only have a small portion of their mode volumes extending outside their high-dielectric regions, making it challenging to bring external entities precisely to within that volume. Third, patterning of organic materials at the nanoscale is extremely challenging and incompatible with inorganic processes. As a result, experimental realizations of systems of excitons of organic molecules and optical resonances are limited compared with systems of inorganic quantum nanostructures.Here, we present and study a unique dielectric surface that enables simple incorporation of organic molecules onto a macroscopic nanostructured resonant cavity. This system demonstrates strongly enhanced interaction of light with organic molecules that are brought to within 100 nm of its m...

International audienceAtmospheric forcing, which is known to have a strong influence on surface ocean dynamics and production, is typically not considered in studies of the deep sea. Our observations and models demonstrate an unexpected influence of surface-generated mesoscale eddies in the transport of hydrothermal vent efflux and of vent larvae away from the northern East Pacific Rise. Transport by these deep-reaching eddies provides a mechanism for spreading the hydrothermal chemical and heat flux into the deep-ocean interior and for dispersing propagules hundreds of kilometers between isolated and ephemeral communities. Because the eddies interacting with the East Pacific Rise are formed seasonally and are sensitive to phenomena such as El Niño, they have the potential to introduce seasonal to interannual atmospheric variations into the deep sea