Grupo de Tecnologías Ópticas y Optoelectrónicas

Our last paper published in Journal of Optics is entitled Extending the degree of polarization concept to higher-order and orbital angular momentum Poincaré spheres.

In this work, done in collaboration with Dr. Carlos Hernández-García, from University of Salamanca, we apply the density matrix formalism that describes any standard polarization state (fully or partially polarized) to describe vector beams and spatial modes with orbital angular momentum (OAM). We provide a comprehensive description of the mapping between the corresponding Poincaré spheres (PSs); namely: the polarization PS, the higher-order PS (HOPS) and the orbital angular momentum PS (OAMPS).

Whereas previous works focus on states located on the surface of these spheres, here we study vector and scalar modes lying inside the corresponding PS. We show that they can be obtained as the incoherent superposition of two orthogonal vector (or scalar) modes lying on the corresponding sphere surface. The degree of polarization (DoP) of a classical polarization state is thus extended to vector beams and OAM modes.

We used a q-plate to experimentally map any state in the polarization PS onto the HOPS, and a linear polarizer to finally project onto the OAMPS. We design a new polarization state generator, based on two geometric phase gratings and a randomly polarized laser, which generates partially polarized light in an efficient and controlled way.

Esther Nabadda received the best poster award at the Workshop on Structured Light and its Applications, organized by the Institute of Physics and the SPIE-OPTICA Student Chapter of the Friedrich Schiller University Jena –  Link

Esther presented the poster entitled «Retrieving the phase distribution of structured light beams by a self-interferometric technique».

María del Mar Sánchez-López and Esther Nabadda have participated at the Workshop on Structured Light and its Applications organized by the Institute of Physics and the SPIE-OPTICA Student Chapter of the Friedrich Schiller University Jena –  Link

María del Mar was one of the featured speakers with the talk entitled «Tailoring depolarization spatial effects with a liquid-crystal SLM».

Esther presented the poster entitled «Retrieving the phase distribution of structured light beams by a self-interferometric technique».

Ignacio Moreno appears included in the last update of the World’s Top 2% Scientists list (Ioannidis, 2022), a list made based on Elsevier Scopus data base – link.

This information has been covered in the article «Investigación de impacto mundial desde la UA y la UMH» at Diario Información – link (in Spanish).

A total of 37 researchers from UMH appear in the list. UMH news – link (in Spanish).

The last issue of UMH-Sapiens includes the section «Donde nace la Ciencia» devoted to the research Intitutes of our university.

The Institute of Bioengineering (IB-UMH) is one of them, and María del Mar Sánchez appears as its vicedirector and representing TecnOpto laboratory.

María del Mar Sánchez participated as a jury member of the Ph.D. Thesis entitled «Tunable Diffractive Liquid-Crystal Photonic Devices» presented at Universidad Politécnica de Madrid by Mario García de Blas, supervised by our colleagues Morten Geday and Xabier Quintana from CEMDATIC-UPM center.

Very interesting work on LC technology.

TecnOpto is offering a predoctoral position to develop a PhD in the field of structured light and its applications, within frame of a research project from Generalitat Valenciana (ref. CIAICO/2021/276).

The research will be developed in conjunction with our colleagues at University of Valencia and at Autonomous University of Barcelona.

If you are motivated for this research in this field, contact us writing to the email:

More details in the next link

TecnOpto participated at the EOS Annual Meeting – EOSAM2022 held in Porto from September 12th to 16th.

Ee presented a communication about our interferometric system for measuring the phase content of structured light beams within the conference Advances and Applications in Optics & Photonics, chaired by Manuel Filipe Costa and María Teresa Flores-Arias.

During the meeting, the European Optical Society General Assembly was cellebrated on September 16th. There, Ignacio Moreno became new member of the EOS Board of Directors for the next two years.

María del Mar Sánchez-López presented our work on the generation of customized depolarization patterns using a LCOS-SLM system on the session «Polarization and Vectorial Shaping and Quantum Optics», as part of the conference «Laser Beam Shaping XXII» of the SPIE Optics & Photonics 2022 held in San Diego (USA) from August 20th to 25th.

This presentation is based on our recent work published in Scientific Reports: Link

Our last paper published in Optics and Laser Technology (OLT) is entitled Mueller matrix polarimetric analysis applied to characterize the physical parameters of a twisted-nematic liquid-crystal modulator.

This work presents a complete polarimetric study of a twisted-nematic (TN) LC cell. We review the existing physical models and analyze the different modulation regimes. We extend the usual Jones matrix approach, where these microscopic physical models were developed, to the corresponding Mueller matrix approach. This polarimetric analysis is then used to obtain the effective linear and circular retardance components of the cell and to characterize its physical parameters like the twist angle, the orientation of the LC director axis and the maximum retardance. The technique simplifies previous approaches with the advantage of employing a single wavelength.

This work is part of the PhD Thesis of Esther Nabadda.