We present a comprehensive derivation of the so-called diffuse to near-normal-viewing reflectance factor of an architectural paint coating and its measurement with an integrating sphere. We focus our attention to the surface correction terms and consider the case when the surface is rough. We point out limits of the standard formula with the so-called Saunderson corrections commonly used for paint coatings. We provide and discuss a corrected definition of the roughness-dependent "gloss factor" needed to describe specular-component excluded measurements. We show that as the roughness of the surface increases, the specular-excluded reflectance-factor increases, approaching its value with the specular-component included.
We present three different techniques for single-mode waveguide realization in Lithium Niobate at the 3.39μm
atmospheric transmission band, named L-band. These methods include Titanium diffusion, Ion Beam Implantation and
Photo-inscription. After describing the fabrication process and waveguide characterization, we will present an integrated
interferometer based on the Young's double slit experiment. From the recorded interferogram we recover information
about the source, namely, its peak emission lines.
Recent developments in the characterization of particle dispersions have demonstrated that complementary information on the joint particle property distribution (size-shape-chemical composition) of micron and sub-micron particles is available from multiwavelength spectrophotometric measurements. The UV-VIS transmission spectra of the microorganism suspensions reported herein were recorded using a Hewlett-Packard 8453 diode array spectrometer with an acceptance angle smaller than 2 degrees. To eliminate concentration and particle number effects, the transmission spectra were normalized with the average optical density between 230-900 nm. Experimental results demonstrate that microorganisms at various states of growth give rise to spectral differences that can be used for their identification and classification and that this technology can be used for the characterization of the joint particle property distribution for a large variety of continuous, on-line, and in-situ particle characterization applications. An interpretation model has been developed for the quantitative interpretation of spectral patterns resulting from transmission measurements of microorganism suspensions. The interpretation model is based on light scattering theory and spectral deconvolution techniques and yields the quantitative information necessary to define the probability of the detection and identification of microorganisms. A data base of 54 pathogens has been created and demonstrates that the technology can be used in the field for real-time in-situ monitoring applications.
We present a theoretical method that makes it possible to analyze 3-D integrated optical waveguides with arbitrary refractive-index profiles. With this method it is easy to obtain effective indices, propagation constants, and coupling/switching properties of planar and channel optical waveguides. This theoretical approach involves modeling the original optical waveguide by means of an equivalent optical waveguide whose eftective index is evaluated by applying a technique that we call the asymptotic eftective-index method. The numerical values show good convergence and accuracy for effective indices, propagation constants, and coupling/switching characteristics. Theoretical and experimental values are given.
We present a theoretical method which makes it possible to analyze 3-D integrated optical waveguides with arbitrary refractive index profiles. With this method it is easy to obtain effective indexes, propagation constants and coupling/switching properties of planar and channel optical waveguides. This theoretical approach involves modelling the original optical waveguide by means of an Equivalent Optical Waveguide whose effective index is evaluated by applying a technique that we call the Asymptotic Effective Index Method. The theoretical results show good convergence and accuracy for effectives indexes, propagation constants and coupling/switching characteristics.