Transmission properties of nonlinear multimode waveguide arrays

Multimode capillary waveguide arrays containing reverse-saturable absorbers exhibit an enhancement of the nonlinear response. Experimental data are modeled by the effect of partial mode filling, influenced by fill fraction and capillary diameter

Two-Photon Accessed Excited State Absorption in bis(terpyridyl Osmium)-(Porphinato)Zinc

Two-photon absorption properties of a (terpyridyl)osmium-(porphinato)zinc (OsPZnOs) are studied in bulk and waveguides. Integration of OsPZnOs (d\u3e1300GM) in waveguides showed enhanced nonlinear performance and potential for photonic applications

Near IR Nonlinear Optics of an Organic Supermolecule

Two-photon accessed excited state absorption is shown to be an important mechanism in the near-IR nonlinear response of an organic supermolecule. This mechanism also provides an enhanced nonlinear absorption in an optical waveguide configuration

Optical limiting in solid-core photonic crystal fibers

Optical limiting in solid-core photonic crystal fibers filled with reverse-saturable absorbers has been observed. A sharp change in limiting threshold was found for materials in the fiber holes with refractive indices near n = 1.44

Predicting Landscape-Genetic Consequences of Habitat Loss, Fragmentation and Mobility for Multiple Species of Woodland Birds

Inference concerning the impact of habitat fragmentation on dispersal and gene flow is a key theme in landscape genetics. Recently, the ability of established approaches to identify reliably the differential effects of landscape structure (e.g. land-cover composition, remnant vegetation configuration and extent) on the mobility of organisms has been questioned. More explicit methods of predicting and testing for such effects must move beyond post hoc explanations for single landscapes and species. Here, we document a process for making a priori predictions, using existing spatial and ecological data and expert opinion, of the effects of landscape structure on genetic structure of multiple species across replicated landscape blocks. We compare the results of two common methods for estimating the influence of landscape structure on effective distance: least-cost path analysis and isolation-by-resistance. We present a series of alternative models of genetic connectivity in the study area, represented by different landscape resistance surfaces for calculating effective distance, and identify appropriate null models. The process is applied to ten species of sympatric woodland-dependant birds. For each species, we rank a priori the expectation of fit of genetic response to the models according to the expected response of birds to loss of structural connectivity and landscape-scale tree-cover. These rankings (our hypotheses) are presented for testing with empirical genetic data in a subsequent contribution. We propose that this replicated landscape, multi-species approach offers a robust method for identifying the likely effects of landscape fragmentation on dispersal