Leaves from in vitro proliferating shoots of cvs. Chandler and Hartley of Persian walnut were cultured on MS and NN media supplemented with BA and NAA. Three light conditions including darkness, low light intensity and modified light intensity were used. Most of the calli were friable and non-embryonic in all three conditions. Rate of callogenesis depended on cultivar, culture medium, light con...

The ambiguity function (AF) provides a convenient way to model how a camera with a modified aperture responds to defocus. We use the AF to design an optimal aperture distribution, which creates a depth-variant point spread function (PSF) from a sparse set of desired intensity patterns at different focal depths. Prior knowledge of the coherence state of the light is used to constrain the optimiz...

Kerr effect accounts for the change in refractive index of a material with the light intensity and appears in all known optical materials. In this work we analyze Kerr effect in structured superluminal media (e.g some specific types of resonators). We show that Kerr effect in these structures can be cancelled or even reversed (in comparison with the Kerr effect of the material composing the str...

Parity-time-symmetric (-symmetric) optical waveguide couplers offer new possibilities for fast, ultracompact, configurable, all-optical signal processing. Here, we study nonlinear properties of finite-size multimode -symmetric couplers and predict the nonlinear oscillatory dynamics that can be controlled by three parameters: input light intensity, gain and loss amplitude, and input beam profile...

Optical nonlinearities of periodically poled LiNbO(3) crystals were investigated by the single beam Z-scan technique with a continuous wave (cw) laser beam at 532 nm. The nonlinear optical absorption coefficient and refractive index change are determined to be 8.1 x 10(-6) cm/W and 2.6 x 10(-4) at 0.5 MW/cm(2) light intensity, respectively. Both sign and magnitude of the measured refractive non...

The angular and temporal distributions of light scattered around the backward direction from biological tissues are measured. An enhancement of scattered light intensity around the backward direction, which is associated with the weak photon localization, is observed. The transport mean free path l(t) and the absorption length l(a) of the light in biological tissue can be obtained from the angu...

We demonstrate the basic operation of an organic/inorganic hybrid single nanowire solar cell. End-functionalized oligo- and polythiophenes were grafted onto ZnO nanowires to produce p-n heterojunction nanowires. The hybrid nanostructures were characterized via absorption and electron microscopy to determine the optoelectronic properties and to probe the morphology at the organic/inorganic inter...

We have achieved high-precision laser beam shaping by using a binary-amplitude spatial light modulator, a digital micromirror device (DMD), followed by an imaging telescope that contains a pinhole low-pass filter (LPF). An error diffusion algorithm was used to design the initial DMD pixel pattern based on the measured input beam profile. This pattern was iteratively refined by simulating the op...

SCRIPPS INSTITUTION OF OCEANOGRAPHY,* UNIVERSITY OF CALIFORNIA, LA JOLLA, CALIFORNIA Communicated by Carl L. Hubbs, August 5, 1955 An investigation of the behavior of the sonic-scattering layer in the region of the San Diego Trough has proved that it is closely associated with the degree of submarine illumination.' This finding could not have been predicted by extrapolating from light measureme...

Molecular orientation fluctuations in ferroelectric smectic liquid crystals produce space charges, due to the divergence of the spontaneous polarization. These space charges interact with mobile ions, so that one must consider the coupled dynamics of the orientation and ionic degrees of freedom. Previous theory and light scattering experiments on thin free-standing films of ferroelectric liquid...