Anisotropic charge displacement supporting isolated photorefractive optical needles

The strong asymmetry in charge distribution supporting a single non-interacting spatial needle soliton in a paraelectric photorefractive is directly observed by means of electroholographic readout. Whereas in trapping conditions a quasi-circular wave is supported, the underlying double-dipolar structure can be made to support two distinct propagation modes.Comment: 3 pages, 3 figure

Soliton electro-optic effects in paraelectrics

The combination of charge separation induced by the formation of a single photorefractive screening soliton and an applied external bias field in a paraelectric is shown to lead to a family of useful electro-optic guiding patterns and properties.Comment: 3 pages, 5 figure

Stable oscillating nonlinear beams in square-wave-biased-photorefractives

We demonstrate experimentally that in a centrosymmetric paraelectric non-stationary boundary conditions can dynamically halt the intrinsic instability of quasi-steady-state photorefractive self-trapping, driving beam evolution into a stable oscillating two-soliton-state configuration.Comment: 3 pages, 4 figs, revtex os

Effects of Baking, Roasting and Frying on Total Polyphenols and Antioxidant Activity in Colored Chickpea Seeds

ABSTRACT Chickpea lines with colored testa (seed coat) contain high levels of polyphenolic compounds that exhibit high levels of antioxidant activity. In a previous study, we showed that common processing procedures, such as soaking and cooking, decrease the levels of these bioactive compounds and subsequent overall antioxidant activity. The observed reduction in total phenolic content was due to the movement of polyphenols from the seed coat to the soaking or cooking water. Here, the effects of baking, roasting and frying processes were examined in relation to total phenolic content (TPC), total flavonoid content (TFC) and ferric-reducing ability of plasma antioxidant activity (FRAP AA) of colored chickpea seeds. Baked, fried and roasted colored chickpea seeds had significantly higher levels of TPC, TFC and FRAP AA than regular cream-and beige-colored seeds subjected to the same treatments. In contrast to our previous results with soaking and cooking, baking, frying and roasting retained most of the TPC, TFC and FRAP AA in the final products. Thus, colored chickpeas subjected to these three processing methods might be considered a functional food in addition to its traditional role of providing dietary proteins

Sparsity-based single-shot sub-wavelength coherent diffractive imaging

We present the experimental reconstruction of sub-wavelength features from the far-field intensity of sparse optical objects: sparsity-based sub-wavelength imaging combined with phase-retrieval. As examples, we demonstrate the recovery of random and ordered arrangements of 100 nm features with the resolution of 30 nm, with an illuminating wavelength of 532 nm. Our algorithmic technique relies on minimizing the number of degrees of freedom; it works in real-time, requires no scanning, and can be implemented in all existing microscopes - optical and non-optical

Spontaneous self-trapping of optical beams in metastable paraelectric crystals

We report on the observation of a new mechanism for self-trapping of optical beams: self-trapping that stems from spontaneous creation of ferroelectric crystalline clusters, seeded by a weak photorefractive diffusion field. This is an evident observation of the highly nonlinear aspects of propagation in a thermodynamically metastable system, including optically driven crystalline ordering in a medium undergoing a phase transition