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-MartÃnez and Eugenio Roldán from UV.
The picture shows us, from left to right Shang Gao, Esther Nabadda, David Marco, Miguel Alonso, MarÃa 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.
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.
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.
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.
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.
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.
On February 27th, 2023 we had the visit of Prof. Elisabet Perez, from the Facultat d’Ã’ptica i Optometria de Terrassa (FOOT), at Universitat Politècnica de Catalunya (UPC).
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.
