Grupo de Tecnologías Ópticas y Optoelectrónicas

A new paper in the journal Optics & Laser Technology entitled Spectral performance of a zero-order liquid-crystal polymer commercial q-plate for the generation of vector beams at different wavelengths.

It deals with the use of liquid-crystal polymer q-plates operated at different wavelengths. We show how a broadband spectral characterization allows identifying the wavelengths with retardance values relevant for vector beam generation (π, π/2, and 3π/2). The wavelength is then used as a tuning parameter to change the device performance from the standard half-wave q-plate to a positive or a negative quarter-wave q-plate.

We present a simple procedure to derive the polarization distribution of the generated vector beams, and show that they can produce hybrid vector beams when operated at non-design wavelenths. Therefore, these results could extend the use of commercial q-plates for multicolour vector beam applications.

This work has been done in collaboration with Prof. Jeffrey A. Davis and Isaiah Abella, from San Diego State University.

Interview to Sirona Valdueza in Diario Información: Link

Sirona is a former student of TecnOPTO, and currently a «Ramón y Cajal» researcher at Univerty of Alcalá: Link to her personal web

She has been one of the speakers at the «II Jornada La Ciencia tiene Nombre de Mujer» that was held at UMH to celebrate the International Day of Women and Girls in Science. In her talk she gave an overview of her experience as a young scientist in the field of photonics engineering with useful tips for girls willing to follow a career in STEM. More details on the program of this workshop can be found here.

Prof. Pascuala García Martínez becomes a Vicedean (Vicedecana de Estudios y Ordenación Académica) of the Faculty of Physics of the University of Valencia.

She is part of new team leaded by Prof. Jordi Vidal, who was elected as the new Dean of the Faculty of Physics in the elections held on March 12th, 2018.

Extended news link (in Spanish)

A new paper published in Optics & Lasers in Engineering presents an experimental method to calibrate a liquid crystal on silicon (LCoS) display by using split-lens configurations displayed on the device. The split-lens directly generates an interference pattern from which the phase modulation is calculated. Additionally, a micro-lens array is displayed on the LCoS, within the same experimental set-up, to implement a Shack-Hartmann wavefront sensor and retrieve the display surface deformation.

This work is entitled LCoS display phase self-calibration method based on diffractive lens schemes, and has been developed by our collaborators at Universitat Autònoma de Barcelona, with the participation of Ignacio Moreno.

Ignacio Moreno participated as invited speaker in the Workshop on Adaptive Optics for Industry and Medicine AOIM XI, organized by Pablo Artal and his group at the University of Murcia, in March 2018, 4-7.

Our latest results on the adaptive generation and detection of vector beams by means of liquid crystal spatial light modulators were presented in the talk entitled «Polarization Diffractive Elements displayed in Liquid Crystal Spatial Light Modulators».

The workshop had very interesting talks, and a great ambience.

The II Jornada La Ciencia tiene Nombre de Mujer was held on February 26th at UMH to celebrate the International Day of Woman and Girl in Science. The purpose of this second edition is to attract female students to Engineering degrees. Recognized female Engineering professionals delivered outreach talks to an audience of about 200 high-school students. Prof. Carmen Vázquez, who talked about Photonics applications in engineering, and Dr. Sirona Valdueza, former student of TecnOPTO, were among the speakers.

A new paper in Optics Express has been published entitled Random technique to encode complex valued holograms with on axis reconstruction onto phase-only displays, by José Luis Martínez-Fuentes and Ignacio Moreno.

This work presents a new technique to encode complex-valued holograms onto a phase-only display, based on a random selection determined by the amplitude level. The proposed technique offers some interesting features like on-axis hologram reconstruction, no iterative calculation, and good efficiency and good computational cost.

We provide here experimental results with computer generated holograms, as well as the generation of Hermite-Gauss and Laguerre-Gauss beams.

Pascuala García gave a conference about gender equity in a training workshop session organized by the Doctoral School of the Universitat Jaume I – UJI, in Castellón.

This session was organized by the Unidad de Igualdad of UJI in celebration of the International Day of Women and Girls in Science, on February 11th, 2018.

Related link (in Spanish).

We published a new paper in Applied Optics entitled Q-plates with a nonlinear azimuthal distribution of the principal axis: application to encoding binary data. This work has been developed with out colleagues at San Diego State University.

Here we use the optical system developed at SDSU to control two linear polarization components to encode q-plates where the angular orientation of the principal axis is varied spatially with a nonstandard distribution. We consider two cases: first, where the principal axis distribution is like an inverse-tangent function of the azimuth; and second, where it displays linear and flat segments. This last case is proposed as a new method for encoding binary data into the azimuthal lobes of the vector beam.

The use of the spatial light modulator based system allows these new and exotic q-plate designs without the difficulty of fabricating individual plates. Experimental results are presented.

Ignacio Moreno attended Photonics West, in San Francisco, in February 2018, 2nd-7th. An invited talk was presented by Jeffrey A. Davis on our mutual collaboration entitled Polarization state vector beam spectrum analyzer using q-plates encoded onto a spatial light modulator at the SPIE OPTO conference  Complex Light and Optical Forces XII, chaired by Enrique J. Galvez, David L. Andrews, and Jesper Glückstad. A related manuscript is available at the SPIE Proceedings Volume 10549, Complex Light and Optical Forces XII; 105490L (2018). Link

Ignacio Moreno, as the current President of the Spanish Society of Optics – SEDOPTICA, signed the renovation of the collaboration agreement with SPIE. The picture shows Dr. Maryellen Giger, 2018 SPIE President, signing the agreement with Ignacio.