In constructing the percept of transparency, the visual system must decompose the light intensity at each image location into two components one for the partially transmissivc surface, the other for the underlying surface seen through it. Theories of perceptual transparency have typically assumed that this decomposition is defined quantitatively in terms of the inverse of some physical model (t...

We describe theoretically and study experimentally nonlinear surface waves at the edge of a modulated waveguide array with a surface defect and a self-defocusing nonlinearity. We fabricate such structures in a LiNbO(3) crystal and demonstrate the beam switching to different output waveguides with a change of the light intensity due to nonlinear coupling between the linear surface modes supporte...

1. Chlorella pyrenoidosa has been grown in a continuous-culture apparatus under various light intensities provided by incandescent lamps, other conditions of culture being maintained constant. The harvested cells were analyzed for cell number, dry weight, nitrogen, and chlorophyll per unit cell volume. 2. Cell nitrogen and cell volume are parallel measures of cellular material over the range of...

In nonlinear optics we are frequently measuring the functional dependence of a physical parameter on light intensity. This immediately presents a problem, since by their nature real optical beams have a varying transverse intensity profile. Any nonlinear measurement will inherently be different at the center of the beam than it is at the edges. A spatially integrated whole-beam measurement must...

A liquid crystal network whose chromophores are functionalized by photochromic dye exhibits light-induced mechanical behaviour. As a result, the micro-scaled thermotropic traits of the network and the macroscopic phase behaviour are both influenced as light alternates the shape of the dyes. In this paper, we present an analysis of this photomechanical behaviour based on the proposed multiscale ...

When orientation is attained under the influence of beams of parallel light opposed at 180 degrees the deflection theta from a path at right angles to the beams is given by tan See PDF for Equation, where I(1) and I(2) are the photic intensities and H is the average angle between the photoreceptive surfaces. This expression is independent of the units in which I is measured, and holds whether t...

We observed an anomalous linear photogalvanic effect (ALPGE) in undoped InGaAs/AlGaAs multiple quantum well and studied its wavelength dependence in details. This effect is believed to originate from the optical momentum alignment effect and the inhomogeneity of light intensity. We find that the spot location with the maximum ALPGE current is wavelength independent. And the normalized ALPGE cur...

The localized coupling between piezoelectric and photoexcitation effects of a ZnO micro/nanowire device has been studied for the first time with the goal of designing and controlling the electrical transport characteristics of the device. The piezoelectric effect tends to raise the height of the local Schottky barrier (SB) at the metal-ZnO contact, while photoexcitation using a light that has e...

The metronomic predictability of the environment has elicited strong selection pressures for the evolution of endogenous circadian clocks. Circadian clocks drive molecular and behavioural rhythms that approximate the 24 h periodicity of our environment. Found almost ubiquitously among phyla, circadian clocks allow preadaptation to rhythms concomitant with the natural cycles of the Earth. Cycles...