To interpret fiber-based and camera-based measurements of remitted light from biological tissues, researchers typically use analytical models, such as the diffusion approximation to light transport theory, or stochastic models, such as Monte Carlo modeling. To achieve rapid (ideally real-time) measurement of tissue optical properties, especially in clinical situations, there is a critical need ...

The evolution of the electronic absorption edge of type I, II and III kerogen is studied by diffuse reflectance UV–Visible absorption spectroscopy. The functional form of the electronic absorption edge for all kerogens measured is in excellent agreement with the ‘‘Urbach tail’’ phenomenology. The Urbach decay width extracted from the exponential fit within the visible range is strongly correlat...

This work introduces a new vision-based approach for estimating chlorophyll contents in a plant leaf using reflectance and transmittance as base parameters. Images of the top and underside of the leaf are captured. To estimate the base parameters (reflectance/transmittance), a novel optical arrangement is proposed. The chlorophyll content is then estimated by using linear regression where the i...

Leaf Incorporating Biochemistry Exhibiting Reflectance and Transmittance Yields (LIBERTY) models the effects of leaf biochemical concentrations on reflectance spectra on the basis of Melamed theory, which has several limitations. These are: (1) the radiation components are not treated satisfactorily; (2) the directional changes of both particle and sublayer scattering ratios are not considered;...

A measurement of the angular and polarisation dependence of the reflectance of an EM1 9124B KaCsSb bialkali photocathode, with the photomultiplier immersed in water, has allowed an unambiguous determination of the KzCsSb complex refractive index (2.7 f 0.1 + i( 1.5 f 0.1) at 442 nm wavelength) and thickness (23 f 2 nm) The wavelength dependence of the refractive index has been obtained from a m...

The thermodynamics of the rapid vaporization of a liquid on a solid surface heated by an excimer laser pulse is studied experimentally. The transient temperature field is measured by monitoring the photothermal reflectance of an embedded thin film in nanosecond time resolution. The transient reflectivity is calibrated by considering a temperature gradient across the sample based on the static m...

Silicon nanowire-based solar cells on metal foil are described. The key benefits of such devices are discussed, followed by optical reflectance, current-voltage, and external quantum efficiency data for a cell design employing a thin amorphous silicon layer deposited on the nanowire array to form the p-n junction. A promising current density of 1.6 mA /cm2 for 1.8 cm2 cells was obtained, and a ...

Mesoporous materials are characterized by the density of empty or filled pores which modulates their properties, in particular, optical properties. Although pores scatter light, the scattered energy or reflectance spectra of a mesoporous layer show a behaviour that can be attributed mainly to interference created by the interfaces; however, coherent scattering is still present inside the mesopo...

Light scattering, or the so-called Yule-Nielsen effect, and ink penetration into the substrate paper play important roles in tone reproduction. We develop a framework in which the influences of both of these effects on the reflectance and tristimulus values of a halftone sample are investigated. The properties of the paper and the ink and their bilateral interaction can be parameterized by the ...

Introduction: Compositions of many of the >100 lunar pyroclastic deposits identified remotely are poorly constrained. In addition, the absorption properties of glasses, which are ubiquitous in all regolith samples, strongly influence spectra of lunar soil and hence spectral remote sensing data of the lunar surface [1,2]. Previous spectral studies of lunar synthetic glasses have not reproduced a...