Alhacén: una revolución óptica

Alhacén es un punto de inflexión en la historia de la Óptica, uno de los nombres clave en el desarrollo de las teorías ópticas y un personaje de gran talla científica. Se pasa revista aquí a su figura, a sus principales aportaciones y la trascendencia de esas aportaciones. En particular, se pone el énfasis en el replanteamiento que Alhacén hace del papel de la luz en la visión y en el modelo intromisivo que propone para esta última

Interferencias de ondas esféricas por reflexiones múltiples en láminas transparentes : sensor óptico para el control automático de espesor

Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Óptica, leída el 14-02-1994Se desarrollan modelos teóricos y resultados experimentales para la construcción de un sensor óptico interferencial para el control automático del espesor de laminas transparentes. El modelo teórico permite plantear el problema en términos abstractos para muestras de geometría e índice de refracción arbitrarios, bajo diversas aproximaciones, se ha podido llegar a una relación sencilla entre el periodo espacial de las franjas del interferograma y el espesor de la muestra. También se ha desarrollado un software especifico que, basándose en un método original de reducción de franjas, permite conocer el periodo espacial de un interferograma de modo automático. A partir de estos resultados, se ha construido un dispositivo experimental simple y de bajo coste, que puede ser útil para usos industriales.Depto. de ÓpticaFac. de Ciencias FísicasTRUEpu

Industrial and technological policy of digital transformation, service and intelligent product connected. Strategies and projects of the energy sector

La política industrial es una acción coordinada de los gobiernos en los niveles europeo, nacional y autonómico, destinada a orientar los recursos de producción a los productores en ciertas industrias para ayudarles a ser más innovadores y competitivos. La digitalización, conectividad e incorporación de inteligencia a los productos y procesos, determina un potencial de competitividad para las empresas, sectores productivos y de servicios, en base a la posibilidad de realizar productos personalizados de mayor calidad y la aparición de nuevas oportunidades de negocios basadas en los servicios para ganar en competitividad. Esta situación, suscita el interés del establecimiento de un marco regulatorio multinivel, multiescala y multisectorial que constituya un facilitador del potencial de estas tecnologías en el desarrollo e Políticas Industriales. En el presente trabajo se formula un protomodelo de establecimiento de Política Industrial para conducir el proceso de innovación a través de la transformación digital del sector industrial y estrategias para su materialización en las distintas empresas. Dicho protomodelo se concreta para el sector energético.Industrial policy is a coordinated action of governments at European, national and regional levels, aimed at orienting production resources to producers in certain industries to help them become more innovative and competitive. The digitization, connectivity and incorporation of intelligence to products and processes, determines a potential for competitiveness for companies, productive sectors and services, based on the possibility of making personalized products of higher quality and the emergence of new business opportunities based in services to gain competitiveness. This situation raises the interest of establishing a multilevel, multiscale and multisectoral regulatory framework that constitutes a facilitator of the potential of these technologies in the development of Industrial Policies. In the present work, a proto model of the establishment of Industrial Policy is formulated to lead the process of innovation through the digital transformation of the industrial sector and strategies for its materialization in the different companies. Said protomodel is specific for the energy sector

Stress separation from photoelastic data by a multigrid method

An application of multigrid techniques for the separation of principal stresses in plane stress systems is presented. By establishing the equilibrium equations and determining the value of shear from photoelastic data a system of partial differential equations is obtained, which can be solved by applying a multigrid method. Multigrid methods are comparable to Fourier methods in efficiency and robustness and can be applied to processing areas of arbitrary shape

Surface plasmon resonance sensors based on uniform-waist tapered fibers in a reflective configuration

We present a configuration for surface plasmon resonance sensors based on uniform-waist tapered optical fibers and reflective elements. Once the fiber is tapered fulfilling the adiabatic criterion, a multilayer including a metallic medium is asymmetrically deposited on the uniform waist of the fiber. This feature provides the resonant excitation of multiple surface plasma waves. In addition, a mirror is produced at the fiber tip by a chemical Tollens reaction. In this way, the sensor operates in a reflective mode, more convenient for dip probes. When these sensors are spectrally interrogated, a high sensitivity of 10^4 refractive index units per nanometer is attained. These devices can be advantageously used for any kind of chemical sensing and biosensing

Hyperparabolic concentrators

We present a family of three-dimensional concentrators constructed from the photic field generated by a Lambertian emitter. The profile of these concentrators is obtained from the field lines for a two-dimensional truncated wedge and is based on the union between a hyperbola and a tilted parabola. By revolution of this profile, we obtain hyperparabolic concentrators (HPCs). In the limiting case when the focal length of the hyperbola becomes the radius of the exit aperture, the HPC becomes the well-known compound parabolic concentrator. On the other hand, when the focal length of the hyperbola becomes infinite, the HPC achieves the thermodynamic limit of concentration

A fast method to measure the irradiance response of image processing systems

A method to estimate in a fast and simple way the response of an image acquiring system (such as a charge-coupled device camera plus an image-processing board) for a monochromatic light source is presented. Two images, whose irradiances are related in a known way, are acquired, and the corresponding grey levels of the responses of the system are correlated pixel to pixel. From this correlation and the relationship between the irradiances of the images, a relative estimation of the irradiance response of the system can be obtained by means of simple algorithms. This method is fast and easy to implement and the results obtained are satisfactory

Theoretical method for the study of plasmon generation in hybrid multilayer-optical fiber structures

A theoretical method is presented for the determination of the behavior of devices based on the deposition of multilayer structures on polished optical fibers. Plasmon generation in metallic layers is modeled. The method is based on the Rayleigh expansion of the electric fields and permits us to determine their distribution over the whole structure by an application of boundary conditions. Once the distribution is known, the power transmitted by the fiber can be computed as a function of the geometrical and refractive parameters of the device. The method is versatile and can be used as a theoretical tool for the design of devices of that type used for many different purposes. We present real experimental results obtained with an operative sensor that agree with the theoretical predictions of our technique and prove its suitability

A transparent TMPyP/TiO2 composite thin film as an HCl sensitive optochemical gas sensor

Tetracationic porphyrin (TMPyP) molecules were incorporated into an optically transparent TiO2 thin film, prepared by Glancing Angle Physical Vapour Deposition (GAPVD), by simple infiltration (at pH 6.4). The preparation of optically transparent TMPyP/TiO2 composite thin films provides a method for the integration of the porphyrin molecules into photonic devices for direct monitoring of gases. Previously, UV-visible and fluorescence spectral techniques have been used to study the reversible protonation of TMPyP in aqueous solution. The optical spectrum of TMPyP shows an intense Soret band at 423 nm with a 22 nm red shift upon protonation by HCl. The experimental conditions for monitoring the concentration of HCl gas by absorption spectroscopy have been optimized. The maximum absorbance change was observed at the Soret band wavelength. A selected temperature of 80 °C and a 300 s recovery period were found to be the optimum operating parameters (response time t50 = 16.8 ± 0.7 s). The composite with smaller surface concentration of TMPyP (¿ = 0.3 × 10-9 mol cm -2) presented the best detection limit (0.1 ppm). The response of the composite sensor was highly stable for several months.Ministerio de Educación y Ciencia PET2007 0363 01/ 02, TEC201021830C0201, CSD20070000