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Photon Scattering Profiles in a turbid media were investigated through numerical simulation based on Monte Carlo-Mie method, at this present work. Using Wolfram Mathematics in the program algorithm. Photon Scattering was treated using electromagnetic spherical harmonics waves, in three-dimensional scattering. The proposal, as an alternative to the Henyey-Greensein phase approximation, was defining an unit vector that represents a phase distribution, as an equivalent function with three vector components, within the turbid media. Associating the step component, as projection using Legendre polynomials and for the transverse plane components were defining as vector bases in terms of Legendre-Hankel functions, according to Gustav Mie theory. This composite vector was defined as a step function and was evaluated within Monte Carlo algorithm, obtaining simulations of light scattering. Backscatter profiles were compared for different geometric dimensions of the spherical particles within the turbid media, including a validation of the model with an experimental Lidar signal from low clouds, obtaining physical properties of the turbid media by the proposed theoretical model.

In this paper, diffraction properties of several gratings are considered on the basis of the Fourier physical theory. Binary gratings with unequal strip width are of particular interest, as well as the case of two interlaced gratings of the same period. Under scope are absorptive gratings, phase gratings, and mixed gratings. Some variants of binary gratings, as the so called Bi-Ronchi gratings (2D-gratings), are also discussed. In particular, phase gratings with absorption (mixed gratings) are also taken into account. The interferograms generated for this type of gratings are shown in this work. As examples, the patterns for a spherical mirror are obtained for different grating parameters and different values of primary aberrations. Some of the resulting relevant properties are remarked. Related experimental works from several structures of the gratings are shown. This study can be used not only for optical testing, but also for light gratings for particle diffraction or to describe diffraction effects of micro-gratings.

In this research we implemented a two-step phase shifting system based on two cyclic-path coupled interferometers for slope measurements of transparent samples. The optical system generates two π-shifted interferograms, and the phase shift between interferograms is obtained by rotating a linear polarizer, generating four interferograms with relative π/2-phase shifts; this simplifies the number of phase steps necessary to retrieve the optical phase, since is only necessary perform a shift operating a linear polarizer. The optical phase was processed by a four-step algorithm. In order to present the capabilities of the system, results obtained for slope for transparent structures are presented.

In this research a novel interferometric system is reported, which allows the generation of four simultaneous interferograms with phase shifts of π/2. The system consists of three coupled interferometers: a rectangular Sagnac interferometer which generates a primary pattern with crossed circular polarizations, coupled to two Michelson interferometers which operate as a multiplexing system, and generating replicas of the primary pattern. The two coupled Michelson interferometers generate four patterns retaining their polarization properties, which allow independent phase shifts by placing a linear polarizer over each pattern, thereby, four interferograms with relative phase shifts of π/2 are obtained. The optical phase is calculated using the well-known four-step algorithm. With knowledge of the optical phase, different properties of the samples can be calculated or analyzed; in this case, by knowing the mean refractive index, we can calculate the mean thickness of test objects. The results obtained for static transparent samples are presented. The capability of the system to analyze dynamic events is shown when results for the calculation of a temperature field of a heat flow are presented.

In optical tomography of parallel projections, the light rays that cross the slice of the object are experimentally approached to suffer minimal refraction, i.e. take refractional limits. Generally, a media is used for immersion whose refractive index rate tied the environment to study, but the geometry of the containment vessels also affects refraction and may be the case that the approach is not subject performed. In this work we make a numerical study of the refraction of a ray of light that enters a typical experimental system for studying the thermodynamic behaviour of a paraffinic wax around their cloud point. Since it has special properties in the heat capacity and refractive index near the phase transition, these results will be used to characterize the transition and is intended to give tomographic information to the study of thermal properties obtained using the T-History calorimetric technique. In this study, we simulate the behaviour of the refraction of parallel rays crossing the T-History test system to find the optimal values of the dimensions of the containment vessels and the index of refraction of the medium for immersion, considering that the optical properties of the sample under study vary with temperature. Thus, we obtain the optimum conditions of minimum refraction technique for which reconstruction of a tomographic slice parallel projection can be applied. The distribution of the linear attenuation coefficient on the slice of the object, typically, is obtained by applying the filtered backprojection algorithm to the set of projections (sinogram) obtained experimentally, which constitutes a way to detect mobile interfacial boundaries in real time. The projections are sequentially measuring the intensity of the wave emerging from the slice of the object at different angles.

Speckle interferometry is a powerful and basic technique to test mechanical parameter. Traditional speckle interferometry is implemented in laboratory, with bulk components. On the other hand, real applications demands of more practical set-ups: compact and robust. Optical fibers present a possibility to substitute some bulk components and to access far and adverse mediums. Based on our experimental experience we discuss the advantages and disadvantages in the implementation of optical fiber in speckle interferometry. In order to observe high constrast of fringes; we tested different and conventional fiber. We compare results from different types of fibers and discussed the viability to implement it in optical speckle interferometry.

Optical tomography of phase objects could be carried out with optical derivatives at the phase detecting stage. A particularly convenient related technique is the use of a fractional derivative of fractional order 1/2, which consists of a spatial filter with square-root amplitude transmittance. An advantage of this type of filter is that it can be implemented as a real filter when dealing with phase objects. Irradiance is proportional to the phase derivative of order one, and it can be obtained. If a tomographic detection system is equiped with such a filter, phase gradient of projections can be determined, and directional derivatives of phase slices can be displayed. Slice images resulting from an experimental tomographic system for parallel projections includes a spatial filter. with square-root amplitude transmittance made from a liquid crystal display operating in amplitude modulation are shown.