Grupo de Tecnologías Ópticas y Optoelectrónicas

On May 17th 2023, Pascuala Garcia-Martinez was interviewed at «Oscilador Armónico”, the podcast broadcast about physics made at IFIC – Instituto de Física Corpuscular, a joint center of CSIC and teh University of Valencia.

The full interview is now available at the following link.

The program of that day was entitled «Óptica, Fotónica y la Física de la Luz»  and along the interview, Pascuala talked about the International Day of Light, some of the many applications that Optics and Photonics has nowadays, and about her work and research.

We had the honor to receive the visit of Prof. Miguel Alonso, Directeur Adjoint de la Recherche del Institute Fresnel, Marseille (France), Professor at the Institute of Optics, University of Rochester (USA) and Editor-in-Chief of the journal Optics Letters.

We invited Prof. Alonso to a combined visit to the Faculty of Physics of the University of Valencia (UV), where he dekivered the conference «The geometry hidden in Optics» and to the Institute of Bioengineering at UMH.

David Marco, who is now finishing a two-year postdoctoral stay at Marseille to work with Prof. Alonso, also joined in the visit. This reunion was held within the frame of a joint project (CIAICO/2021/276) of Generalitat Valenciana, also with the participation of Pascuala Garcia-Martínez and Eugenio Roldán from UV.

The picture shows us, from left to right Shang Gao, Esther Nabadda, David Marco, Miguel Alonso, María del Mar Sánchez-López and Ignacio Moreno.

A new paper is now published in Optical Engineering entitled Multiplexing onto a spatial light modulator using random binary patterns. In this paper we analyze the random approach for encoding a variety of independent outputs from a multiplexed computer-generated diffractive element displayed on a SLM. Although the technique was demonstrated years ago, nowadays it can be applied with high-resolution SLMs with a very large number of pixels, thus allowing for a larger number of multiplexed functions without significant degradation. Nevertheless, we show that the technique is quite sensitive to the pixel crosstalk caused by the fringing field of modern LCOS SLMS, leading to a significant undesired DC order. Two alternative strategies to avoid this degradation.

The work has been done in collaborators Jeffrey A. Davis and Don M. Cottrell from San Diego State University (USA). It is the first paper published by PhD student Shang Gao.

Our new paper entitled Liquid crystal anisotropic axicon for the generation of non-diffracting Bessel beams with longitudinally varying polarization is now publised in the journal Optics and Laser Technology.

In this work we demonstrate a tunable liquid–crystal element of linear phase profile along the radial coordinate. In combination with a regular refractive axicon, it behaves as an anisotropic axicon, generating the collinear superposition of two orthogonally polarized Bessel beams with different propagation constant. This superposition results in a Bessel beam where the state of polarization (SOP) varies periodically along propagation.

The work has been done with our collaborators at the Military University of Technology, Warsaw (Poland), Noureddine Bennis, Anna Spadlo and Tomasz Jankowski, together with José Francisco Algorri, from University of Cantabria, in Santander (Spain).

We have attended SPIE-COS Photonics Asia 2023 conference, held in Beijing in October 14-16th, 2023, organized by the Chinese Optical Society and SPIE. We have participated at the conference on Holography, Diffractive Optics, and Applications XIII.

Ignacio Moreno delivered the invited talk entitled Diffraction gratings with full amplitude, phase, and polarization control: physical realization on liquid-crystal spatial light modulators. María del Mar Sánchez-López delivered the invited talk entitled Triplicator phase grating implementation in pixelated displays. PhD student Shang Gao also attended the conference.

A great opportunity to meet in person the Chinese optical community.

The SPIE proceedings of these two works are now available at:

Proceedings Volume 12768, Holography, Diffractive Optics, and Applications XIII; 127681B (2023) – Link

Proceedings Volume 12768, Holography, Diffractive Optics, and Applications XIII; 127681G (2023) – Link

We have participated in the Annual Meeting of the European Optical Society, EOSAM2023, held in Dijon (France) in September 11-15th, 2023.

David Marco delivered the talk entitled «Mapping partially polarized light to incoherent superpositions of vector beams and vortex beams with orbital angular momentum», where he presented our recent article published in Journal of Optics.

Esther Nabadda gave the talk «Complete Mueller matrix imaging polarimeter for evaluating optical components for structured light», where she presented our new imaging polarimeter system.

Finally, Ignacio Moreno participated in the event as the new EOS Secretary of the Board of Directors, and as co-chair of the Focus Session on Structured Light.

Great time in a great conference!

Esther Nabadda and Ignacio Moreno collaborated in the work entitled Connecting the microscopic depolarizing origin of samples with macroscopic measures of the Indices of Polarimetric Purity, published on the journal Optics & Lasers in Engineering. The work was leaded by our colleagues Juan Campos and Angel Lizana at UAB MIP-Optilab, in the frame of our coordinated joint research project.

In this work the indices of polarimetric purity (IPP) are analyzed as metrics to study the depolarization characteristic of media. It shows two different depolarizing origins: isotropic and anisotropic depolarization. The former, isotropic depolarization is related to pure scattering processes. Anisotropic depolarization is originated by microscopic constituent elements showing polarimetric anisotropy (dichroic and/or birefringent elements with different characteristics) and anisotropic scattering produced by these elements.

TecnOpto contributed to the experimental validation with radial polarizer and radial retarder measured with a Mueller matrix imaging polarimeter.

We have participated in the World of Photonics 2023 held in Munich (Germany) in June June 27–30, 2023.

David Marco attended CLEO-Europe conference, where he delivered the talk entitled «Mapping relations between the polarization, the higher-order and the orbital angular momentum Poincaré spheres for inner points», where he presented our recent article published in Journal of Optics.

Pascuala García-Martínez attended the SPIE Digital Optical Technologies 2023 conference, where she gave the talk «Polarization Fourier filtering with a 4f system using geometric phase lenses».

TecnOpto participated at the conference Reunión Naci0nal de Optoelectrónica – OPTOEL 2023, organized by SEDOPTICA in Sevilla in 14-16 June 2023.

We contributed wit two posters presented by our PhD Students Esther Nabadda, entitled «Mueller matrix polarimeter and birefringence imaging», and Shang Gao, entitled «Implementation of triplicator diffraction gratings in a pixelated display». Books of Abstracts.

We had the pleasure to meet there Massimo Santarsiero, one of the inventors of the triplicator grating.

A new paper is published in Optics Express entitled Dual Fourier transform processor using geometric-phase lenses by Pascuala García-Martínez and Ignacio Moreno.

This work presents a novel optical system for polarization image processing using geometric-phase (Pancharatnam-Berry) lenses. These lenses present the same focal length but opposite sign for left and right circular polarizations. Therefore, they split an input collimated beam in a converging beam and a diverging beam with opposite circular polarizations. Here we profit from these properties to build an optical Fourier filter system with polarization sensitivity. A telescopic system is used to have access to two real Fourier transform planes, one for each circular polarization. A second symmetric optical system is used to recombine the two beams onto a single final image. As a result, polarization sensitive optical Fourier filtering can be applied, as demonstrated with simple bandpass filters.