Microlens arrays can improve light transmittance in optical devices or enhance the photoelectrical conversion efficiency of photovoltaic devices. Their surface morphology (aspect ratio and packed density) is vital to photon management in solar cells. Here, we report a 100% packed density paraboloidal microlens array (PMLA), with a large aspect ratio, fabricated by direct-write UV laser photolithography coupled with soft imprint lithography. Optical characterization shows that the PMLA structure can remarkably decrease the front-side reflectance of solar cell device. The measured electrical parameters of the solar cell device clearly and consistently demonstrate that the PMLA film can considerably improve the photoelectrical conversion efficiency. In addition, the PMLA film has superhydrophobic properties, verified by measurement of a large water contact angle, and can enhance the self-cleaning capability of solar cell devices.

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We address the dynamics of fundamental and higher-order dark solitons on the intense parabolic background in a planar graded-index waveguide with self-defocusing nonlinearity. It is shown that dark solitons on the parabolic background can propagate stably, and feature the properties similar to dark solitons for standard nonlinear Schrödinger equation. We present an approximate solution for dark soliton on a parabolic background, and discuss its motion trajectory. In addition, the interaction between neighboring dark solitons on parabolic background is investigated.

Tight confinement of light in subwavelength waveguides induces substantial dispersion of their nonlinear response. We demonstrate that this dispersion of nonlinearity can lead to the modulational instability in the regime of normal group velocity dispersion through the mechanism independent from higher order dispersions of linear waves. A simple phenomenological model describing this effect is the nonlinear Schrödinger equation with the intensity dependent group velocity dispersion.

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This paper presents the intrinsic fluorescence spectra characteristics of tryptophan, tyrosine and phenyloalanine measured with 3D fluorescence spectrophotometer. Two strong fluorescence peaks of tryptophan locate at λex/λem=230/348nm and 280/348nm, three strong fluorescence peaks of tyrosine locate at λex/λem=202/304nm, λex/λem=220/304nm and 275/304nm, and two fluorescence peaks of phenyloalanine locate at λex/λem=210/280nm and λex/λem=260/280nm were found. The linear relationship of fluorescence intensity to solution concentration were also observed in condition of low solution concentration. The influence of pH of solution to the fluorescence intensity was also measured and discussed.

BACKGROUND AND PURPOSE:The thermogenesis of BAT is believed to be controlled through some pathways initiated in the brain, though the changes in brain activity among different states of BAT-positive subjects are still unclear. We hypothesized that some significant differences of regional cerebral metabolism between various groups were related to the BAT activities regardless of temperature changes.