Toroidal surfaces are surfaces of revolution generated by revolving a plane curve about an axis in the plane of the curve. To avoid the generation of self-intersecting surfaces, the extent of the curve is restricted, so that the curve does not intersect the axis. Unlike aspherical surfaces, there is no standard mathematical representation for toroidal surfaces. In the present work we propose equations for the sagitta, the unit normal vector and the principal curvatures of a toroidal surface which are appropriate for ray tracing purposes, and also for the propagation of thin pencils of rays. In addition, we derive the equations corresponding to a revolving curve with the shape of a conic section, from which one can readily deduce the equations corresponding to a toric surface. All these equations are of considerable importance in ophthalmic lens design, where the refraction of thin pencils of rays is required, and it is commonly performed with the aid of Coddington equations.

We show experimental results to determine the depth of inhomogeneities such as glass spheres and biological human tumors, in semi-solids organic materials, like gels (phantom), using the non invasive optical technique called 3D Pulsed Digital Holography (PDH). We reported previously that this technique may be used for the detection of biological tissues¹. 3D Pulsed Digital Holography allowed us to make a quantitative analysis of the changes that the phantom suffers when it contains inhomogeneities as compared to a phantom that does not have one. The results obtained there showed quite remarkably the internal fault in semi-solids. In here we report early results obtained from three different object illumination positions that gave 3 wrapped phase maps that allowed the calculation of the depth position of the inhomogeneity within the phantom. The optical technique used looks at the phantom surface micro displacement, where measurements are correlated to the z position of the inhomogeneity inside the phantom. Likewise, the technique is able to show the deformation that the material undergoes in x, y, and z.

We present an experimental arrangement based on a Michelson interferometer, which uses a He-Ne laser as a source of illumination to obtain a pattern of fringes starting from a beat of the heart simulated by a computer. Of the pattern of fringes the original sign is reconstructed and is compared with the simulation of the heart beat.

The development of laser skin perforator device for obtaining blood samples is presented. The use of photoelectric proximity photoelectric sensor permits to determine the focal point eliminating any contact and them avoiding the risk of contamination. Perforation of about 0.2 mm - 0.5 mm in diameter can be obtained in order to take the sample of blood. The method permits to make the blood analysis not only avoiding the contamination risk but also diminishing the pain sensation in comparison with metal lancet.

This contribution explains the physics principles of titanium-sapphire laser and the technology used to produce ultra-short pulses of 100 fs, at a 76 MHz rate, 13 nJ energy per pulse with an average power of 1.1 W. The characterisation of the laser pulses and the potential applications uses indirect optical methods for them, such as, optical autocorrelation, interference and spectrometry. This contribution describes the multiple applications in several fields of science, engineering, medicine and telecommunications. Finally an optical arrangement, for the characterisation of pulsed laser and its potential applications is discussed and the measurements that can be done in the Laboratory.

The development of a single mode optical fiber standard, for the distance scale calibration of Optical Time Domain Reflectometers (ODTRs) is presented. The configuration of the standard is based on a Recirculating Delay Line (RDL) which generates a series of reflections at constant intervals of time; such reflections are used as distance references using a nominal group index of the fiber. The optical modulation-phase-shift technique was used to characterize the transit time of the reference fiber, at the 1310 nm and 1550 nm communications windows. The characterization method provides the sensibility coefficients of the two dominant influence quantities, optical signal wavelength and temperature of the fiber.

In this work we present the fabrication process of channel waveguides by ionic exchange on a glass substrate. To delimit the channel areas on the glass substrate two procedures are used. The first one is by conventional lithography, making use of an aligner, photoresist and a mask. The second consists in implementing a holographic interferometer to imprint on the photoresist layered substrate, a straight fringes interference pattern of desired period. The glass index increasing in the channels area is obtained by Na+/K+ ionic interchange. We present the near field characterization results of the waveguides fabricated by the conventional method; as well as results of the parameters optimization and grids, fabricated by the holographic method.

Light beams and light pulses (in general any wave packet) tend, in a natural way, to broad as they propagate in a linear material. Optical solitons are beams that do not suffer broadening as they propagate in a nonlinear material. Spatial optical solitons are beams where the natural diffraction is compensated by a self induced refractive index change in the media, creating its own waveguide. The importance of spatial solitons is their capacity to create its own waveguide (like optical fibers). The fact that a spatial soliton can creates a refractive index change in the media, following its intensity profile, allows that other beam can be confined inside it. As a result, light guiding light, allows thinking that spatial solitons can be used as active and passive elements of interconnection in all optical communication systems. In this work we present a phenomenological, numerical and experimental study on the generation and properties of spatial solitons in different media, but that can be describe by the nonlinear Schroedinger equation. In particular we are going to focus in that solitons that can be generated using cw light beams; this means that the response time of the nonlinearity in the media is larger than milliseconds.

Optical waveguides have been produced in Nd:YAG and Nd:YVO₄ crystals by either proton or carbon implantation. The analysis includes refractive index profiles, spectroscopic properties and particularly laser emission characteristics in the YAG guides. Typical optical barrier profiles were obtained when protons were used. In the case of YVO₄, carbon implantation produced a considerable refractive index variation in the guiding region, increasing the ordinary index and reducing the extraordinary index. The spectroscopic studies show that emission bands coming from the ⁴F_3/2 level are not significantly altered by the ion beam process, thus maintaining the crystal quality in the guiding region. The YAG waveguides exhibit good laser emission characteristics at 1 064 nm and high stability in the CW regime.

We present the results of an experimental study of dynamic amplitude and phase Bragg gratings induced in a heavy-doped Erbium fiber at the wavelengths 1 532 and 1 538 nm under the 980 nm pumping. The technique of two phase-modulated beams' coupling was applied for an experimental measurement of the changes in refractive index and gain accompanying the gratings' formation in the fiber, and an analysis based on the Kramers-Kronig Relations for the fiber absorption/gain spectra and two-pass amplifying was performed for modeling these changes.

We introduce equipment for the automatic activation of a three-phase electric motor (1Hp, 3A, 240V AC) using 2 infrared sensors monitored by a Microchip microcontroller PIC16F62x@4Mhz for the control of a filling system. This project was carried out to Fabrica de Chocolates y Dulces Costanzo, where the automatization of cacao grain supply was required for a machine in charge of cleaning the cacao from its rind. This process demanded the monitoring of the filling level to avoid the spill of toasted cacao.

A novel hydrodynamic radial polishing tool (HyDRa) is presented. It performs corrective lapping and fine polishing of diverse materials by means of a low-cost abrasive flux and a hydrodynamic suspension system that avoids contact of the tool with the working surface. With this tool it is possible to polish aspheres and free-form optics on diverse materials and sizes. The functioning principle is based on the generation of a grazing, high-velocity, low-pressure, rotational, variable density, abrasive flux with radial geometry. It has the advantage of avoiding fallen edges during the polishing process as well as reducing tool wear out and deformation. The polishing process is repeatable and achieves high degrees of precision and accuracy on optical and semiconductor surfaces. This tool is particularly useful for polishing thin substrates such as membranes and semiconductors since it can be biased for a non-interactive action on the work piece. An additional advantage of this new tool is the possibility to perform in-process interferometric measurements. Polishing results on assorted materials using HyDRa are presented.

The existent techniques to produce high number of patterns replication, is determinates with the sampling theorem from Fourier theory. Following this line with matrix array of m x m points, we propose to construct a lens with hybrid optics technology; in our case we used a sum of Fourier holograms, to obtain four or more diffracted zones than the conventional conjugate pair of Fourier hologram. These codes are engravings in the surface of the glass lens. Using polymers or by techniques of glass erosion. To obtain a hybrid system lens with a hologram incorporate as one element. This point is important because reducing and agrees more value to conventional optics lenses; the lens can be adapted to production systems for mass patterns replication, for the graphic arts industry. We showed of this proposal some preliminary results.

A low cost technique based on the UV-VIS absorption spectroscopy is presented for the quality control of the spirit drink known as tequila. It is shown that such spectra offer enough information to discriminate a given spirit drink from a group of bottled commercial tequilas. The technique was applied to white tequilas. Contrary to the reference analytic methods, such as chromatography, for this technique neither special personal training nor sophisticated instrumentations is required. By using hand-held instrumentation this technique can be applied in situ during the production process.

The fabrication of polymeric optical fibers (POFs) must consider the obtain of very transparent, homogeneous, compatible and processable materials, the possibility to conform them in structures with diverse degrees of sophistication, and the fulfillment of the operation characteristics imposed on the finally obtained fibers. To meet all of these requirements a series of problems, related to the intrinsic properties of polymers and their processing, have to be solved. In this work we address the solution given to some of the roughest problems of POF fabrication within the context of a preform drawing based system.

The use of the photoacoustic technique for real time monitoring of the efficiency and cleaning sites localization during the laser assisted removal of the spiky glochids from prickly pear fruit is proposed. Prickly pear areoles were irradiated with high energy microsecond Nd: YAG laser sequence of pulses up to the entirely removal of the glochids agglomerate. Strong selective absorption of the laser radiation leads to the formation of a high pressure plasma. The photoacoustic experiments were done in open air conditions using a standard electret transducer. Results obtained from photoacoustic signal analysis display high sensibility and signal to noise ratio for in situ monitoring of the process.

A qualitative analysis of laser breakdown experiment in prickle pear ablation is presented. The experiments were made using a pulse free-running Nd:YAG laser, and consist in irradiating both the areole and cortex zones. It was find out that the intensity of spectra captured from ablated glochids depends from number of pulses and the presence of water. The picks observed on the electronic noise can be associated with combustion products obtained during thermal laser interaction. It was demonstrated that LIBS technique can be used for on-line monitoring in laser de-thorning machine.

The optimization of an automatic laser cutting system is reported. This CO₂ laser system assisted by an O₂ gas jet is used in the cutting of Constant Velocity (CV) joint for the automotive industry. The experimental parameters varied in order to obtain cuts with low roughness were the laser power, cutting speed and oxygen pressure. A mathematical model is presented which explains many of the features of the qualitative optimization realized.

This work presents how performance of a simple Michelson interferometric configuration, allows monitoring of oxide layers growing in aluminium structures during preliminary states of oxidation processes in aqueous solutions, without any physical contact with the sample. The alternative experimental arrangement introduce a more simple alignment compared with preliminary proposals, and the obtained interferograms offer a qualitative and quantitative interpretation of important physical parameters related to specified corrosion processes. Finally, a potential improvement in order to obtain monitoring of samples through turbid solutions is discussed.

We present results of optical measurements in products or processes usually found in industrial processes, which can be used to control them. Laser light scattering was employed during semiconductor epitaxial growth by molecular beam epitaxy. With this technique, it was possible to determine growth rate, roughness and critical temperatures related to substrate degradation. With the same scattering technique, oil degradation as function of temperature was monitored for different automotive lubricants. Clear differences can be studied between monograde and multigrade oils. Optical rotation measurements as function of temperature were performed in apple juice in a pasteurization process like. Average variations related to optical rotation dependence of sugars were measured and monitored during heating and cooling process, finding a reversible behavior. As opposite behavior, sugar-protein solution was measured in a similar heating and cooling process. Final result showed a non-reversible behavior related to protein denaturation. Potential applications are discussed for metal-mechanic, electronic, food, and pharmaceutical industry. Future improvements in optical systems to make them more portable and easily implemented under typical industry conditions are mentioned.

This work proves an experimental model for the detection and location of a radiation punctual source that use plastic scintillating optical fiber (PSF). The principle it based in the conversion of the radiation to light pulses in side of the scintillating material¹, arrive times of these light pulses are measuring in the extremes of the fiber. In addition, the results give the basis for an experimental model that measures light pulses intensity in constant time acquisitions.

We show experimental results of the optical analysis carried out to conductive polymers of polyaniline generate by chemical bath method. These polymers shows changes in their optical and physical properties when they are exposed to low concentrations of aqueous ammonia. We analyze the spectral changes that presents these polymers as a function of the wavelength in the interval at [350 nm - 1100 nm], in order to determine the spectral bands with more sensitivity to ammonia. We evaluate the feasibility to employ these conductive polymers as optical sensors for remote monitoring of ammonia.

Flow visualization refers to a method used for qualitatively obtain information in the field of fluid mechanics. In this work, we show a simple single lens system using laser light illumination to observe flow dynamics using a setup similar to the schileren setup. As we will detail, it is based on a phase contrast technique in which the filter is made of a nonlinear optical material, therefore it is self-aligned and depends mainly on the illuminating intensity. Due to these characteristics, the resulting setup is extremely robust and builds up within a few milliseconds.

The combination of molecular exclusion chromatography and laser polarimetric detection has turned into a carbohydrate separation and quantification system for plant fluids of industrial value, making it possible the evaluation of the quality of sugarcane juices, agave juices and many other plant extracts. Some previous papers described a system where liquid chromatography separation and polarimetric detection using a LASERPOL 101M polarimeter with He-Ne light source allowed the collection and quantification of discrete samples for analytical purposes. In this paper, the authors are introducing a new improved system which accomplishes polarimetric measurements in a continuous flux. Chromatograms of several carbohydrates standard solutions were obtained as useful references to study juice quality of several sugarcane varieties under different physiological conditions. Results by either discrete or continuous flux systems were compared in order to test the validation of the new system. An application of the system to the diagnostics of scalded foliar is described. A computer program allowing the output of the chromatograms to a display on line and the possibility of digital storing, maxima detections, zone integration, and some other possibilities make this system very competitive and self-convincing.

Fluorescence methods are being used increasingly in the measurement of species concentrations in gases, liquids and solids. Laser induced fluorescence is spontaneous emission from atoms or molecules that have been excited by laser radiation. Here we present a time resolved fluorescence instrument that consists of a 5 μJ Nitrogen laser (337.1 nm), a sample holder, a quartz optical fiber, a spectrometer, a PMT and a PC that allows the measurement of visible fluorescence spectra (350-750 nm). Time response of the system is approximately 5 ns. The instrument has been used in the measurement of colored bond paper, antifreeze, diesel, cochineal pigment and malignant tissues. The data acquisition was achieved through computer control of a digital oscilloscope (using General Purpose Interface Bus GPIB) and the spectrometer via serial (RS232). The instrument software provides a graphic interface that lets make some data acquisition tasks like finding fluorescence spectra, and fluorescence lifetimes. The software was developed using the Lab-View 6i graphic programming package and can be easily managed in order to add more functions to it.

In holography the development and manipulation of materials is determinant for holographic register. Inside this variety of materials there exist the photopolymers and thermopolimeros, materials that have a great potential in holography. In our work we say specifically to the polyvinyl alcohol, it has a dual behavior between photo and thermosensibility. We take advantage of these characteristics for digital holograms replications. We present quantitative results as the diffraction efficiency in the holograms storage as quality parameter. Bearing in mind variations in the states of hydrolysis of the PVA, this form we determine the viability of the use this material for the production of holograms replications in mass.

The molecular dope and his concentration can be change the conductivity of the polymer in several magnitude orders. Everything will depend on the final characteristic that ensues from the process estereochemical, from the polymer and of the chemical and physical factors that they are involved process. We present in this manuscript the evolution characterization of the resistivity parameter of a solution formed by a polymer (PVA) doping with metallic salt (FeCl₃) construct a conductive polymer. We present quantitative results of the temporary evolution and behaviour of the resistivity parameters of some solution to different concentrations considering his physical and chemical properties.

Radiating doped carotenoids synthesized at INAOE by an ultraviolet beam, significant conductivity and chromatic changes are observed, being useful for several applications as would be an images recorder material of high resolution cured with UV radiation, using its transmittance modulation.

In this paper, we report preliminary results of molecular structural changes in cement and concrete caused by laser radiation at 10.6 μm. One of those structural changes is the generation of glazes. At low laser powers, the glazes are small and lined up while at high powers, the glazes are bigger and randomly distributed. In the not exposed to laser radiation concrete, the Raman spectrum presents weak peaks at 200 cm^-1, 550 cm^-1, 700 cm^-1, 750 cm^-1 and 1 150 cm^-1. However, these peaks are amplified by laser exposure and other peaks appear at 800 cm^-1 and 1050 cm^-1. The intensity of all the peaks is dependent on laser radiation power.

Flow velocimetry techniques and Temperature Sensitive Paints, (TSP), requires working with different laser beam intensities. Because velocity flow measurements needs high level laser power compared with temperature surface measurement, where lower levels of laser power is required, is necessary to adjust the system to avoid the damage of the paint due to the high intensities in laser velocimetry measurements. The use of paint of different grey levels (from white to black) as backgrounds above the TSP film deposition allows to make temperature measurements with high laser power without damaging the TSP. This work is centered in the characterization and testing improvements of the temperature surface measurements using Temperature Sensitive Paints as a part of the 3D tunneling velocimetry system.

Third-order nonlinear properties of polymer films doped with triarylmethane dyes have been measured by using third-harmonic generation (THG) for fundamental wavelengths within the range 1 100 nm - 1 600 nm. Our studies show that the triarylmethane dyes Crystal Violet and Ethyl Violet, with a multidirectional charge transfer in their 3-fold symmetry structure (octopolar dimensionality), exhibit large third-order nonlinear coefficient and low residual absorption for harmonic wavelengths, leading to a high conversion efficiencies of THG. The studied films are good candidates for ultra-fast optical correlators.

Erbium doped, SiO₂ - TiO₂ powders were fabricated using the sol gel technique. The Er³⁺ concentrations were 2%, 5% and 10% (mol), and 10%, 25%, 50%, 70% for the TiO₂. A strong, green up-conversion luminescence was found in the samples when exciting at 1532 nm and 978 nm. The recorded spectra showed less intense emissions at 410 nm and 675 nm. The excitation and emission mechanisms proposed were supported on experimental results, such as the absorption and emission spectra, the decay times and the luminescence intensity versus pump power.

The preparation and characterization of organic photorefractive polymer composites derived from (2-(p-chlorophenyl)-(3'-nitrobenzo[d])-(4''-methoxybenzo[h])-1,3-dioxa-6-aza-2-boracyclonon-6-ene, a push-pull boronate, which shows NLO properties, are described. The polymers are based in the photoconductor poly(9-vinylcarbazole) and the plasticizer 9-ethylcarbazole PVK:ECZ matrix, and C₆₀ as sensitizer. For the photorefractive performance, two different chromophore concentrations were used, in addition, the ratio of PVK:ECZ was varied to see the effect on the room temperature molecular orientation. Holographic experiments in a tilted four and two wave mixing geometry were performed by using a 10 mW He-Ne laser (632.8 nm). The experiments were performed at room temperature, with a fixed grating spacing Λ of 2.9 μm, for determining the electric field steady-state diffraction efficiency dependency and the optical gain of the composites. Acceptable photorefractive properties were observed for a polymer with a glass transition temperature T_g of 77°C. Even at this T_g, the response time was less than one second.

A micro-Raman system is used to study the β-carotene of dry and fresh carrot samples in environments with variations of the temperature between 16°C and 120°C. It is shown that the Raman peaks intensities of the dry sample diminish considerably, due to the strong degradation of the β-carotene with the increment of the temperature. Also, for the fresh sample in deionized water, the Raman peaks intensities of the β-carotene, starting from 40 to 50°C, diminish, due to its degradation and diffusion on the surface of the sample and in the water. The same tendency is observed for the β-carotene of the carrot juice.

The optical anisotropy of a semiconductor surface can have different origins, such as, local-field effects, the electro-optics effect, reconstruction, surface dislocations, and surface roughness. A comprehensive, quantitative picture on how these effects are related to surface optical anisotropies (SOA) can now be obtained thanks to the progress in the modeling of optical properties of surfaces. Linear optical spectra can now be calculated very accurately even for large and complex surface structures. This allows a much better understanding of the origin of specific SOA. In this paper we make a review focused on the microscopic origin of SOA and the present state of the art in the study of reflectance anisotropy spectroscopy of semiconductor surfaces.

It is described an Electronic Speckle Pattern Interferometer (ESPI) used for Young's modulus measuring of a new PVC material. The technique considers the construction of a small tensile testing machine that is good enough to apply loads on the polymeric specimens. A dual-illumination ESPI system is built up to measure specimen in-plane micro-displacements under the tension loads. For Young's modulus measuring, strain is required and determined by the force per area unit. Since the specimens have irregular traversal section, the self-imaging or Talbot-projected fringe technique is implemented for determining such a transversal section all along the specimen. Experimental results by using these optical techniques are shown, as well as, the measure of a new polymer Young's modulus.

Photoluminescence (PL) belongs to the group of non-destructive characterization techniques, which consists basically in causing to impact light in a region of the material under study. Then, the material absorbs part of the energy of the incident light and, as a consequence, emits light. This technique is widely employed in different areas of the Industry and Basic Research; for example, in Medicine, Chemistry, Biology, Physics and in several areas of Engineering. As excitation source it can be used lamps, lasers and even solar light. On the other hand, there are processes that can occur to extremely short time scales. In this case new techniques have been developed. Among them, we can mention Time Resolved Photoluminescence. In this technique ultra-short laser pulses are employed which have a temporal width from a few nanoseconds (x10^-9 sec) until femtoseconds (x10^-15 sec). The use of pulsed lasers has served for the development of new methods of investigation and technologies, as has been the case of Femto-Chemistry, new Surgery methods in Medicine, Micro- and Nano- machining of materials, etc. In our case, we utilize Photoluminescence and the Time Resolved Photoluminescence for the characterization of semiconductors materials that have potential applications in Optoelectronics.

We show preliminary results of the implantation of a stabilized Michelson interferometer for the characterization of ultrasonic transducers. The detection system consists of a Michelson interferometer in which a feedback system has been integrated to set the interferometer at the linear region of detection and to compensate optical phase changes introduced by environmental vibrations; this allows us to work in the most sensible region of the system and obtain output signals proportional to the detected displacements (< 10 nm). The obtained results show that it is possible to detect ultrasonic displacements close to 0,2 nm in a bandwidth of 3 MHz using a He-Ne laser with an output power of 1 mW. Preliminary characterization of ultrasonic displacements generated by an ultrasonic transducer immersed in a water tank was performed using this interferometer.

Using an array of laser microscope and a photoluminescent material, we can differentiate the upper and lower extremes of a specimen without changing the focus. It contributes a non-destructive test, which increases the perception of details at microscopic level.

In this work an interferometric experimental setup that allows measuring the oscillation frequencies of vibrating objects is presented, using the photo-EMF effect. Due to the high sensibility of the interferometers this system can detect oscillations in the order of some nanometers. At the moment, the system can work in a frequency interval from 500 Hz to 5 kHz. However the bandwidth can be enlarged in a very simple way by changing some electronic elements, such as resistor and capacitors.

Mechanical devices are normally used under conditions of dynamic motion. Due to resonance effects, this condition produces undesired modes of vibration, which are necessary to be measured for satisfactory design. This work describes the use of laser vibrometry in conjunction with fringe projection and the proper orthogonal decomposition method to analyze the dynamical behaviour of a metal plate when subjected to external vibration. In the proposed method, point velocity measurements of the metal plate obtained by a laser vibrometer are put in phase by the use of an instantaneous out-of-plane displacement image obtained by the fringe projection technique. In this case, the plate was driven by an electromagnetic shaker which in turn was fed with a range of frequencies that covered the first 4 resonant modes.

The feasibility of detecting localized defects in tubing using Wavelet based laser-induced ultrasonic-guided waves as an inspection method is examined. Ultrasonic guided waves initiated and propagating in hollow cylinders (pipes and/or tubes) are studied as an alternative, robust nondestructive in situ inspection method. Contrary to other traditional methods for pipe inspection, in which contact transducers (electromagnetic, piezoelectric) and/or coupling media (submersion liquids) are used, this method is characterized by its non-contact nature. This characteristic is particularly important in applications involving Nondestructive Evaluation (NDE) of materials because the signal being detected corresponds only to the induced wave. Cylindrical guided waves are generated using a Q-switched Nd:YAG laser and a Fiber Tip Interferometry (FTI) system is used to acquire the waves. Guided wave experimental techniques are developed for the measurement of phase velocities to determine elastic properties of the material and the location and geometry of flaws including inclusions, voids, and cracks in hollow cylinders. As compared to the traditional bulk wave methods, the use of guided waves offers several important potential advantages. Some of which includes better inspection efficiency, the applicability to in-situ tube inspection, and fewer evaluation fluctuations with increased reliability.

We present a comparative study of the light reflection in the visible region for different wood species (red cedar, pine, banak, acer negundo and walnut) and different humidity levels for each species. We observed dependence in the percentage of the light reflectance with the humidity and with the species.

We report the light reflectance of powders of nanocristalline alloys of silver (Ag) and silver oxides (Ag₂O), molybdenum and molybdenum oxides (MoO₃) and silver-molybdenum alloys (Ag₂Mo), (Ag₂Mo₂) and (Ag₂Mo₄) for different wavelengths 360 nm - 740 nm. We observed a dependence of the light reflectance with the purity of the silver and molybdenum oxide, and a displacement of the maximum of the reflectance from 450 nm to 550 nm in the presence of the molybdenum oxides.

There are several optical methods of experimental stress analysis, including moire, speckle, and photoelasticity. Among these methods, photoelasticity has advantages in that it is less expensive, simpler, and yields complete information relatively quickly. Photoelasticity methods are useful for both the inspection and measurement of the magnitude and direction of stresses in structures, which leads to improved designs and efficient damage detection. In this project we describe the photoelastic technique and show experimental results that may benefit the industry.

The Proper Orthogonal Decomposition (POD) method is applied to the vibrations analysis of a metal plate. The data obtained from the metal plate under vibrations were measured with a laser vibrometer and Fringe projection technique. The metal plate was subject to vibrations with an electrodynamical shaker in a range of frequencies from 100 to 5000 Hz. The vertical velocity displacement measurements were taken on a quarter of the plate in a rectangular grid of 7 x 8 points using a Laser Vibrometer. The plate vibration measurements were used to calculate the eigenfunctions and the eigenvalues. It was found that a large fraction of the total energy of the vibration is contained within the two first POD modes. The essential features of the deformation are thus described by only the two first eigenfunctions.

A brief review of the state of the art in quantitative photoacoustic spectroscopy for thermally thick samples is presented. We demonstrate that it is possible to find an analytical expression that allows studying the optical absorption coefficient by combining the amplitude and phase of the photoacoustic signal, obtained from the heat diffusion model, for thermally thick samples.

We present an in situ image recognition system in order to inspect the standards of quality of chocolate pops during their production. In high percent, the stick of pops is not settling in the right position and it is our predictable quality problem. The recognition system compares a reference image with the image of chocolate pop under test, in order to determine if this pop has the stick in right position. As result of this work, we obtain the parameters that can help to determine which pops meet the standards of quality.

We design a tomographic system to the slices study of transparent objects with the using parallel projection. The tomographic system is based in a common-path interferometer and this is equipped with a phase-shifting system and a rotate system. Rotate system, sample position at particular angle of projection. Through a visual interface, the projections arriving of the slice object are captured and storage. In this paper, we shown a novel technique of projections capture, which we get a both advantage, it reduces time of capture and diminishes the memory space of computer. Therefore, notably diminishes the processing time. Finally, the optical tomograph construction is discussed and some interfero-sinograms of transparent samples are shown.

Ground penetrating radars (GPR) are useful underground exploration devices. Applications are found in archaeology, mine detection, pavement evaluation, among others. Here we use a GPR to detect by an indirect way, the anomalies caused by the presence of water in the neighborhood of an underground water pipeline. By Fourier transforming a GPR profile map we interpret the signal as spatial frequencies, instead of the temporal frequencies, that composes the profile map. This allows differentiating between signals returning from a standard subsoil feature from those coming back from anomalous zones. Facilities in Mexican cities are commonly buried up to 2.5 m. Their constituent materials are PVC, concrete or metal, typically steel. GPRs are ultra-wide band devices; leak detection must be an indirect process since echoes due to the presence of underground zones with high moisture levels are masked by dense reflections (clutter). In radargrams the presence of water is visualized as anomalies in the neighborhood of the facility. Enhancement of these anomalies will give us the information required to detect leaks.

We describe a dynamic optical active apodizator based on polymer dispersed liquid crystal (PDLC). By applying a voltage, the diameter size of device can be controlled. Two different techniques to control the diameter size are reported. In the first technique the voltage dependence is accomplished by confining PDLC between two flat glass plates making a wedge. Since both plates are coated with ITO, the PDLC response to an applied voltage varies lineally with its thickness. The design and characterization of this optical device are shown.

The majority of holograms are made using interference of light and computer-generated holograms. In this work we propose a technique in real time to generate digital holograms with a VLSI digital component, being specific FPGA and a liquid crystal device. The digital design with FPGA presents great advantage for its parallel procesing that carry out by its flexible structure, high integration and velocity. The design was verified using the platform MathLab/Simulink and Xilinx System Generator.

We present a new threshold technique based on the character grey level percentage. The method is used in the binary segmentation process of characters in a license plate recognition problem. In this case, image contrast problems (i.e. shadows) are found due to variations in the illumination. These image contrast problems generate bad character segmentation such that a binary threshold adaptive algorithm is required. The grey level percentage is calculated from the image histogram. This percentage is used to find the threshold value. Results of the binary threshold process over real license plate images are presented.

The present paper discusses an improvement for the method by division of cells which is used in multiplexed computer generated holograms (CGH's). Such improvement allows increasing the final number of codified images into a single hologram. Some important properties of images are saved because they will be the key to perform the adequate operations involved in the reconstruction process. The experimental results demonstrate the effectiveness of the suggested procedure.

When a liquid is deposited on a surface, this one form a certain angle with respect to the surface, where depending on its value, it will conclude that so hard it is his adhesion with the surface. By means of the analysis of images we looked for to measure this angle of superficial tension. In order to make this measurement, we propose a technique by means of projective transformations and one method of regression to estimation parameters to conic fitting.

In the last years, Soft computing techniques, such as Genetic Algorithms, Neural Networks and Fuzzy systems, have been applied in different science areas. In this work, two applications of Genetic Algorithms in engineering and optics are presented. The Genetic Algorithms are optimization, search and learning machine techniques, which work in a random way. To achieve the problem solution by using of Genetic Algorithms, an iterative process should be developed. First, the problem to solve is modelled in a mathematical way by establishing of a fitness or objective function. After, a random initial population of strings (chromosomes) codifying problem solutions is generated, which samples the search solution space of the fitness function. Then, offspring populations are generated from previous one by using genetic operators: selection, crossover and mutation. In the selection process, possible solutions are chosen depending on their fitness function value. Then, in the crossover procedure, string segments of pairs of solutions are exchanged to generate the next population. Finally, some parameters in the offspring population are changed by mutation with a low probability. Results of the application of Genetic Algorithms to solve fringe analysis and nesting in finite materials problems are presented.

A technique for shape detection using a laser line and neural networks is presented. In this technique, an object is scanned by means of a laser line. From the scanning, a set of images is captured by a CCD camera. By processing these images, the object shape is recovered. The topographic information is extracted from an image by detecting the laser line position in the image plane. To determine the mathematical model of the relationship between the laser line position and the object surface, neural networks are applied. To carry it out, Bezier functions are used to construct the architecture of the neural networks. Using neural networks in this technique, the object shape is obtained by image processing and the parameters of the optical set-up are avoided. In this manner, the accuracy of the topographic measurements is improved. The results of this examination are presented by computer simulation and experimentally verified.

The automatic, non contact measurement of objects in industrial applications is one of the most important applications of the optical 3-D shape measurement methods. A well established 3-D shape measurement technique is triangulation with structured light. In this paper, it will outline on two important aspects of this technique: pattern-codification strategy and calibration procedure, in order to obtain a high accuracy reconstruction.

The possibility of secure communication with chaos is demonstrated experimentally with two simple unidirectionally coupled electronic circuits. A traditional approach has been used to synchronize the two chaotic systems. We also study, both numerically and experimentally, the dynamic of the systems in a wide range of the control parameter. The bifurcation diagrams represent a complex behaviour whish varied from periodic orbits to chaos of the Rossler and Shilnikov types. The results of numerical simulations are in a good agreement with experiments.

We present recent applications of robust half-quadratic regularization for solving common problems in interferogram analysis. Specifically, we review half-quadratic cost functions for: phase unwrapping noisy and discontinuous wrapped phase maps, phase refinement process for computed coarse phases, as those obtained from partial-field patterns with a full-field method for open fringes analysis, for phase retrieval from closed-fringe interferograms and phase denoising. The cases of convex and the non-convex cost functions are analyzed: The convex formulation produces unique and noise-free solutions, but such solution are deteriorated by real discontinuities in phase maps; therefore, we also present a non-convex formulation which, with an extra computational cost, shows a superior performance.

The principle purpose of this work is to providing some general analysis and interpretation in both theory and techniques concerning high accuracy of the thin metallic wire diameter measurement. The closest estimation of the magnitude requires understanding and analyzing the interaction between light and matter (wire). The wires diameter we re concern is between 30 to 500μm. The work is focus on both science and metrology. To reach this goal the simplicity and accuracy is required especially for an industrial automatic implementation control. The article is organized as follow: the section one consist of analyzing and understanding of theoretical interpretation for laser diffraction by thin metallic wire. The second section contains analysis of the experimental set-ups used for calibration and measurement. The followed section is data analysis to estimate the angular location of the minima. With some conclusions we close to achieve the work.

We present the application of the method recommended by the Commission Internationale de L'Eclairage (CIE), in the determination of the correlated color temperature for the FEL type incandescent lamps, used in the Laboratorio de Espectrorradiometria de Lamparas of the Centro Nacional de Metrologia of Mexico (CENAM) as reference standards in the measurement and calibration services for this quantity. The knowledge of the correlated color temperature of a lamp allows it to be used as a particular CIE illuminant; and therefore permits its application in the visual evaluation of colors in several industrial processes. Also, we present the uncertainty estimation for the determination of the correlated color temperature of the evaluated FEL type incandescent lamps.

We present the implementation of the ultraviolet (UV) radiation dose measurement system at the Laboratorio de Dosimetria Optica (LDOS) of the Centro Nacional de Metrologia (CENAM). The UV dose measurement ranges established so far cover from 12 Jm^-2 to 7 256 Jm^-2 and from 171 Jm^-2 to 102 842 Jm^-2, for 254 nm and 365 nm, respectively; corresponding to two emission lines of an arc Hg(Xe) lamp. Those dose ranges can be reached with exposure times from 2 s to 10 min and the reference dose uncertainty has been estimated to be of ±5,4 %.

An appropriate setting of the OTDR can help to improve the calibration reducing the uncertainty of measurements. We present some criterions for setting the Optical Time Domain Reflectometer (OTDR) for its distance scale calibration by means of a Recirculting Delay Line (RDL). The evaluation of some parameters such as location of the event, span of measurements, distance range and pulse width were carry out experimentally using a RDL calibrating system.

An experimental setup for phase extraction of two-dimensional phase distributions is presented. The system uses a common-path interferometer consisting of two windows in the input plane and a translating grating as its pupil. In the output, interference of the fields associated with replicated windows is achieved by a proper choice of the windows spacing with respect to the grating period. Because in this type of grating interferometer a grating is placed as a spatial filter, the phase changes which are needed for phase-shifting interferometry can be easily performed with translations of the grating driven by a linear actuator. Some experimental results are shown.

Traceability to national standards provides confidence in measurements results, granting a guaranty when carrying out governmental rules and when demonstrating conformity with quality requirements such as ISO 9000 or ISO/IEC 17025 (and the Mexican equivalent standards). The appropriate traceability contributes with confidence of the quality of products or services. This paper presents different ways to obtain traceability in Mexico for the optical radiation measurements, mentioning some applications, and highlighting the necessity of having traceability to the appropriate units of the SI. Additionally it present the national standards maintained by Centro Nacional de Metrologia (CENAM), the national metrology institute in Mexico, that give the technical support to Mexican measurements in this field and the international recognition that the personal of the Optics and Radiometry Division had gained in 10 years of development.

We propose a simple technique for determining the refractive indices of highly absorbing materials. This method uses two transmittance measurements at oblique incidence. A theoretical analysis of the proposed method is presented. The refractive index of water was experimentally determined with a relative error ranging from 0.12% to 1.3%. We discuss the extension of this method to spectroscopic measurements.

Full field optical interferometry known as ESPI (Electronic Speckle Pattern Interferometry), has been applied to dynamical deformations on solid and semisolid objects. Although microscopic (1 to 30 micrometers), these deformations offer enough information to know even an early crack detection of the material. In industrial and biomedical environments however there is a lot of noise bigger than the signal we try to recovery, therefore is necessary to compensate mechanical or digitally or both. In this paper we will discuss the basic operating principle of the interferometer and analyze its performance. The technique use a continue wave laser for illuminating the tested object. The transient event is recorded by an ultra fast digital image camera. Data processing is completed with a help of a spatio-temporal algorithm. Some results are presented.

The Large Millimeter Telescope (LMT)¹ is a 50 m diameter millimeter-wave telescope designed for principal operation at wavelengths between 1mm and 4mm. The LMT secondary mirror will have a diameter of approximately 2.6 meters and focal ratio of .35. The purpose of this study was to implement the incoherent fringe projection technique and the spatial phase synchronous method to measure the secondary mirror mold profiling. The obtained topography is compared with the conic surface generated synthetically. We considered that mold should be hyperboloid surface with paraxial curvature of 1764.9 mm and conic constant of -1.1474. We will discuss the preliminary results where it is obtained a RMS of 0.624 cm.

Implementation of a structured light projection technique for measuring the relief of objects, or object areas, of micrometric size (approximately 500 μm x 500 μm), is described. It is well-known that when a fringe pattern is projected on an object, the fringes are deformed according to the topography of its surface. This deformed fringe pattern is a modulated optical signal that allows us to measure the relief of the object. Through one of the oculars of a stereomicroscope, previously focused on the object under study, the fringe pattern of one the Talbot self-image is projected. The deformed fringe patterns are observed by the other ocular, in which a CCD camera is mounted to digitize them. Digitized fringe patterns are demodulated by means of a second virtual reference grating. As a result, a moire fringe pattern is obtained delivering a wrapped phase map when is digitally processed by means of a phase recover technique. Phase recovery techniques for obtaining the wrapped phase maps are phase-shifting and spatial phase synchronous. Experimental results and the conditions, under which the topography of an object section is determined, are shown. Also, comparisons over quality between the phase recovery techniques are discussed.

This paper presents the common sources of errors on illuminance measurements caused by incorrect techniques applied in those tests, causing low confidence studies. Even though the NOM-025-STPS-1999, a compulsory standard in Mexico, gives the guidelines to evaluate lighting conditions on working areas, several methods used by technicians produce results that could be wrong, with serious consequences to workers and some troubles in legal aspects. Since illuminance is the quantity to be measured, its value is strongly influenced by environmental conditions of the room to be inspected and they can change unexpectedly; also the lack of known of the metrological characteristics of measurement instruments increase significantly the errors on those measurements.

The experimental evaluation of the relative spectral response of a standard photometer is presented; the measurements were carried out by the substitution method by means a double monochromator in the range of 405 nm to 730 nm with 5 nm resolution wavelength. The experimental uncertainty and its mismatching factor f₁' are evaluated as part of the routine procedure to realize the candela unit with trazability to an absolute cryogenic radiometer which is the national standard of radiant flux at CENAM (National Center of Metrology of Mexico).

We showed the application of the three cornered hat method to estimate the absolute frequency stability of three semiconductor lasers stabilized to the D₂ line of ¹³³Cs (852 nm). We estimated the relative frequency stabilities between couples of lasers using the beat frequencies measurements and calculating the Allan variance. Neglecting the correlation terms between lasers, it is possible to establish a group of equations which relate the absolute stability in terms of the relative stability. We found stability values of about 1x10^-10 for averaging time of 1 second and 1x10^-12 for averaging time of 1 hour. The results are in agreement with the resonance spectrum linewidth of Cesium and the lasers linewidth.

This work presents the effect of the spectral bandwidth (SBW) in the measurement of neutral density filters (NDF) transmittance. The method used to evidence this effect was the convolution between the monochromator slit function and the measurement of real spectrum of the NDF.

At the moment the National Center of Metrology (CENAM) develops to the necessary technology for the creation of a frequency standard of high accuracy denominated CsF1 atomic fountain. The first stage of development of this clock consists of laser cooling and trapping neutral Cs-133 atoms. The mechanism of laser cooling and trapping of atoms requires of the accomplishment of a magneto-optical trap (MOT) in where is indispensable to maintain a strict control in its parameters of operation. In this experiment, the MOT operates with three set of red detuning |6²s_1/2, F=4|-> |6²s_3/2, F'=5| cyclical transition of Cs-133, mutually orthogonal, counterpropagating laser beams, with opposite circular polarization, intersecting at the center of a magnetic field which is generated by a pair of coil in anti-Helmholtz configuration. Additionally, a beam of light that comes from a repumping laser, tuned to the frequency of the |6²s_1/2, F=3|->|6²s_3/2, F'=4| transition of Cs-133, is injected to the MOT to maintain an atoms population in the |6²s_1/2, F=4| state. To cool and trap atoms to so low temperatures, of the order of the microkelvins on the zero absolute, by several seconds, minutes or even by several hours, provided the fundamentals tools to us to study the temporal and spatial behavior of the fluorescence of the atomic cloud and to make exact measurements in the count of such, in order to deduce the parameters of operation of the MOT that allows us to trap 10¹⁰ atoms or more. In this work the theoretical concepts as well as the experimental details of the parameters of operation of the MOT for the formation of the cold atom cloud are approached.

A new method to characterize silicon photodiodes in the visible range, 380 nm through 780 nm, is presented. This methods uses a constant spectral power source with a thermal stability of filament better than 1 K over 2 999 K, that is the operation temperature. The spectral source consists of tungsten halogen thermally stabilized light source and a monocromator with focal length of 50 cm and a diffraction grating of 150 grooves/mm. The source allows a reproducibility of 0.2 nm and 0.01 % on intensity. The test silicon photodioode's resposivity shows a maximum deviation of 1.25 % on the spectral range as compare to a similar silicon photodetector calibrated by Newport Co.

The performance of Light Emitting Diodes (LEDs), including efficiency, flux level, lifetime, and the variation of color, is advancing at a remarkable pace. LEDs are increasingly used for many applications including automotive, aviation, display, transportation and special lighting applications. White LEDs are expected for general lighting applications (solid state lighting) in the near future. Thus, accurate measurements of LEDs and appropriate standards are increasingly important. This paper reviews photometric, radiometric, and colorimetric quantities used for LEDs, and discusses the current state of optical measurements of LEDs and standardization efforts in International Commission on Illumination (CIE). The paper also touches on the issue of color quality (e.g., Color Rendering Index) of light expected from solid state lighting, and the need for a new metric. The calibration facilities and services for LEDs established at NIST are also discussed.

Laser shock processing (LSP) has been proposed as a competitive alternative technology to classical treatments for improving fatigue and wear resistance of metals. We present a configuration and results in the LSP concept for metal surfaces treatments in underwater laser irradiation at 1064 nm. A convergent lens is used to deliver 2.5 J/cm² in a 8 ns laser FWHM pulse produced by a Q-switch Nd:YAG Laser. Experimental results using a pulse density of 5 000 pulses/cm² and spots of 0.8 mm in diameter in 1040 steel samples are presented. Compressive residual stress distribution as a function of depth is assessed by the hole drilling method. High level compressive residual stresses are produced using 1064 nm wavelength. This method can be applied for surface treatment of final metal products.

This paper pretends to demonstrate the design, construction and test of an opto-electronic system measures external loads apply to a mechanical element (load cell)¹. This device works under the action of external loads and voltage differential to convert a digital signal. This function principle is related with the variation of the angle of incidence of the light signal on an electronic element sensible to light. A difference between this method and other conventional methods it is precisely that the sensible element is not exposed directly to work loads. This prototype represents an alternative method to industrial applications.

In March 2004 was accepted in the site of Gran Telescopio Canarias (GTC) in La Palma Island, Spain, the Commissioning Instrument (CI) for the GTC. During the GTC integration phase, the CI will be a diagnostic tool for performance verification. The CI features four operation modes-imaging, pupil imaging, Curvature Wave-front sensing (WFS), and high resolution Shack-Hartmann WFS. This instrument was built by the Instituto de Astronomia UNAM in Mexico City and the Centro de Ingenieria y Desarrollo Industrial (CIDESI) in Queretaro, Qro under a GRANTECAN contract after an international public bid. Some optical components were built by Centro de Investigaciones en Optica (CIO) in Leon Gto and the biggest mechanical parts were manufactured by Vatech in Morelia Mich. In this paper we made a general description of the CI and we relate how this instrument, build under international standards, was entirely made in Mexico.

GUIELOA is a Curvature type Adaptive Optics system for the 2.1 m San Pedro Martir Telescope. It performs a bimorph 19 actuators deformable mirror and a 19 lens-let array for the wave-front sensor (WFS). GUIELOA corrects effectively the first 8 Zernike polynomials of the aberrated wave-front produced by the atmospheric turbulence. For the closed loop control it performs two SPARC FORCE 5 SBC computers working in concert. The lens-let array + optical fibers send the light from defocused pupil images to 19 avalanche photo-diodes. In this work it is shown how the lens-let array was manufactured at IAUNAM with CIDESI and Centro de Investigaciones en Optica (CIO).

We present the results of the analysis and signal processing in real time of interferometric patterns produced by a Mach-Zehnder interferometric Fiber-Optic temperature sensor. The variations in temperature are seen as the displacement of the concentric rings that conform the interference pattern. The vision system allows us to get interferometric patterns by means of a CCD camera. This image is treated in real time by a program developed in Visual C++. This program allows us to determine the temperature of the sensor. To accomplish this task the displaced rings of interference pattern are counted with respect to a fixed point. The results of the analysis are used in the characterization and optimization of the sensor. The implemented system and the results of the analysis can be applied to other sensors or integrated optic devices based on phase modulation.

We present an ABCD transfer matrix spatial mode analysis of a holographic laser oscillator (HLO), carried out in order to determine the parameters for optimum optical phase conjugation of the Gaussian beam spot size. Those parameters allow a large mode size and efficient energy extraction operation of the studied HLO configurations. The HLO is formed by a nonlinear medium in a self-intersecting loop geometry incorporating a mobile intracavity lens and a feedback mirror acting as output coupler.

Most of the investigations that exist about the interferometer of Sagnac in our days, are made through fiber optic, which has the great advantage of having a big area size in very little space wound in a nucleus. The first interferometers of Sagnac, were used for very big angular speeds measures, it didn't have the advances to carry out detections of small signs, because the measurements systems like photo-detectors, amplifiers, filters, etc. didn't have the capacity of the systems that now exist. That is one reason that our experiments are based on the electronic advances, to make detections of phase changes of until less than 0.1 nm with area of 0.025 m². Besides we proposed changes in the original interferometer diagram, adding some elements that can helps to achieve a bigger sensibility, accuracy and reduction of noise. Another of the advantages of use an interferometer of Sagnac, is work directly with the beams that travel through it, because we can observe the behavior from the optic road to external physical effects, like angular velocity or speed and little movements.

Throughout all this paper we are going to analyze one application of the optical beam deflection method, the procedure for its development, as well as its ideal implementation to reach measurements of displacements that could be the most accurate and of the smaller scale possible, this condition is essential for the magnitude of the results to evaluate. We also give and introduction of the optical beam deflection method, it is characteristics and some of their latest applications as an auxiliary technique on research and commercial fields. This present work will be analyzed the laser beam deflection technique, the procedure to apply, as well as its ideal implementation in order to obtain measures of displacements that can sense to the most exact and of smaller possible scale, obtaining results from microns, micrometers and until nanometers. The importance of this work resides in that the technique although is simple and has easy implementation, the results that can hurtle they are very reliable; thanks to it, the laser beam method of deflection has been not only diffused in many fields of the science and the technology of the optics, but also in those where its application is innovating. This has ended up being a technique of huge utility on interdisciplinary use and has been used to measure physical parameters in a great variety of experiments.

Light-Emitting Diodes (LEDs) have matured to the point that they can be considered to replace the inefficient and short life incandescent lamps in many lighting applications. Though modern high power LEDs produce up 120 lumens per device, several individual LEDs must be mounted on panels to obtain practical powers. In this paper we analyze, by considering each single LED as an imperfect Lambertian emitter, the first order design of a lamp consisting of several LEDs assembled upon a spherical surface to uniformly illuminate far targets. Practical formulas are derived for the optimum LED-to-LED spacing, i.e., the optimum packaging density, of ring array configurations to achieve uniform far-field irradiance.

We present a novel approach for the combination of high power multimode diode lasers. The design considered to ensemble several pigtail multimode diode lasers in a radial position on a circular thin disk (the lid) which has a hole-concentrator at the center point. The reflect mirror which is in charge of concentrating the beams at one point and overlapping them without mutual spatial interference is a paraboloidal mirror which is sprayed by a silver thin reflectance film and it is physically covered by the lid. We simulate this device by using commercial software for optical design and we will show the complete analysis of the ray traces as well as the coupling efficiency of the system.

The basic optical set-ups used for speckle interferometry have a limited capability to study transient events due to the synchronization with the acquisition devices. This capability is explored in this work and compared with recent developed techniques such as the temporal phase unwrapping.

The existing methods for controlling laser dynamics are considered and classified depending on a type of the control and on a control goal. I describe the most important, in my opinion, theoretical and experimental results which can help in solving some real fundamental and technological problems.

When it is carried out to perform a three dimensional evaluation of displacements and strains, it has been proposed some optical systems which uses three illumination beams or the use of three sensors. The different sensitivity vectors components associated to each illumination beam; let us permit to calculate the displacement in each direction by sensitivity matrix. In the present work, simple geometries of interferometers are discussed. It is showed the sensitivity components for each source in the case of optical set-up with three divergent illuminating beams, where we analysed the sources position that makes possible measure the u, v and w components with a maximum weight factor in each direction respecting to set-up total sensitivity. The sources position is one on x-axis, the second on y-axis and the third near to z-axis. From the theoretical predictions is proposed an interferometer which is based on the ESPI technique which has the sources configuration calculated. Experimental results of displacements are presented to an elastic surface when a rotated load is applied in the centre of the target.

A fiber optic sensor (FOS) for high voltage telemetry is proposed. FOS is constituted by 100 m of multimodal fiber coupled to a transducer element based on the electro-optic effect with a double pass configuration of the light wave through a Bi₁₂TiO₂₀ (BTO) fotorrefractive crystal. To guarantee the double pass, a back-reflective prism with high stability to environmental changes of temperature is incorporate to the transducer element. The double reflection of the light wave in the prism allows the BTO to work in a wide linear region of the transfer function. To prove the feasibility of this FOS, a periodic wave of AC and a transitory event, both of high voltages, applied to an aluminium tube were measured from a distance of 1 mt. It is demonstrated that the proposed sensor is robust, linear, and stable against the variations of temperature and of high sensibility for applications of high voltage telemetry.

In this work a numeric analysis is carried out to calculate the thermal lens effect in the stability of a barside-pumped-resonator at 808 nm. The active medium is a Nd:YVO₄ crystal. It is demonstrated that the thermal effects produced by the radiative process, in certain conditions can take one of the planes to a non consistency, having as a consequence an oscillator that will work in intermittent form.

The physical and electrical needs of flash lamp pulsed Nd:YAG lasers are presented. Typical energy converters are reviewed and a SMPS HB-ZVS-MRC 2KW is presented as a solution, along with experimental results. This converter has the characteristics of high power density, high efficiency and low cost, being an excellent option to achieve a laser system of high performance.