Laser Beam Characterization

 Since 1985 we have contributed in the characterization of the propagation and transformation of laser beams. As a result of the PhD dissertation titled "Paraxial formulation of the laser beam optics", we initiated a research work of theoretical character.  Within this line we made several contribution in the matricial treatment of the laser beam optics, and in the characterization of light beam by global figures. An important achievement in this direction was the PhD dissertation of Dr. Miguel A. Porras, titled "Laws for the propagation and transformation of laser beams by ABCD optical systems".  This line is still alive with the study of the transformation of the characteristic parameters when the the beam crosses an interface between two media.

 

Matricial Optics and Array Optics

In 1989 the Optics Department invited Prof. Wang Shaomin for a Sabatic stay in the University Complutense of Madrid. This fruitful collaboration was reinforced with a new visit of Prof. Wang Shaomin in 1992. We could learn from him the basic concepts of the matricial formalism used to describe optical arrays. This opportunity allows us to apply these systems in some technological applications where optical arrays show a clear advantage. A very interesting application was the design of an array for natural illumination in architecture. We have filed and obtained a patent for this task.  In 1998, the PhD dissertation of Dr. Hala Kamal, titled "Design and Properties of Array Optics", summarized the most of our contribution to this field. In this dissertation we found a theoretical framework for the improvement of the design of Array Optics having integration properties. Some other arrays were analyzed and tested with great success in colaboration with the Micromechanic Institute of Neuchate (MIN)l. In this collaboration with MIN we could find some interesting relations for the practical design of Moiré magnifiers working as cooperative optical arrays.

Application of the Principal Component Analysis in Optics

We have developed classification and identification procedures of noise proccesses in a video sequence. The main contributions of this research lare included in the PhD dissertation of José Manuel Lopez-Alonso titled "Characterization of Noise in Image-Forming Systems" (July, 2002). The treatment is based in the application of the Principal Component Analysis (PCA). Thanks to the contributions of Dr. López-Alonso, this technique has been succesfully applied  not only to characterize noise and noise sources in image-forming systems, but also to reveal correlation structures within sets of data of various origins: from multi-spectral images to stock exchange values. The method was applied to understand the generation of confined modes in microcavities fabricated with photonic crystals. In close collaboration with the University Autonoma of San Luis Potosí, the PCA technique has been used to treat Raman spectra in dermatology with very good results for the detection of atopic dermatitis and nickle allergy. As a side effect of the cumulated knowledge in this field we could apply this technique to analyze the semantic content of written texts. The results were included in the PhD dissertation of Paz Ferrero, titled "Definition and analysis of quantitative linguistic parameters for automatic assessment tools applicable to Spanish as a Foreign Language"

Optical Antennas and Resonant Structures

Since 1989 we have stablished a fruitfull collaboration with Prof. Glenn Boreman (now with the University of North Carolina at Charlotte, USA), who was at the time the Head of the Infrared Technology Laboratory of the CREOL / School of Optics (University of Central Florida, Orlando, Florida, USA). . Within this collaboration we have made several contributions to the analysis of infrared systems and in the most recent past in the characterization and analysis of infrared antennas. As a consequence of this collaboration we have reinforced the research ties with Prof. Javier González, now at the University Autonoma of San Luis Potosí (Mexico). Our contribution to this field has been focused on the improvement of their detection figures of merit. We have also developed a measurement station for the characterization of optical antennas in the visible and the infrared. In this area, the PhD dissertation of José María Rico-García could be considered as the first dissertation in this field in Spain. Dr. Rico-García analyzed the response of optical antennas and measured with great resolution its spatial response in the visible. Thanks to several research projects we have now a state-of-the-art measuring station for optical antennas working as light detector. Following our research interest we have analyzed the response of passive resonant structures able to modify the polarization state, or the phase of an incoming wavefront. Also, we have teamed up with Prof. Gabriel Abadal and his group (University Autónoma de Barcelona, Spain) to include optical antennas within cantilever structures to induce mechanical vibration from optical radiation.

Applied Optics for the Industry

The previous lines of research have been complemented with a continuous collaboration with the industry and institutions to implement practical solutions into everyday problems. Optics and Photonics, as enabler technologies irrigate a wide variety of areas of high-tech applications, ranging from optical inspection systems to infrared optics. The Applied Optics Complutense Group (AOCG)has consolidated an important number of contracts and grants with companies to applied optics and photonic into their products and procedures. Dr. Alda, as a member of the AOCG, participates in several projects and grants in this area.