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Our former student Venancio Calero presents his PhD Thesis at FEMTO-ST Institute


VenancioOur former student Venacio Calero, presented his PhD Thesis entitled “Antenne à cristal photonique électro-optique pour la détection de fréquences électromagnétiques”, supervised by María Pilar Bernal and Nadège Courjal at the FEMTO-ST Institute, in Besançon (France), on December 19th, 2017.

Ignacio Moreno attended the defense and participated as a member of the jury.

 


Viernes, 5 de enero de 2018 Sin comentarios

New paper in Journal of Biophotonics about imaging biological tissues based on the indices of polarimetric purity


IPPsWe participated in a new paper published in Journal of Biophotonics entitled Polarimetric imaging of biological tissues based on the indices of polarimetric purity.

This work has been developed by our friends at Universitat Autònoma de Barcelona in the frame of the common coordinated collaboration project.

In this work we use the indices of polarimetric purity (IPPs) for the inspection of biological tissues.

Compared with standard polarimetric images of biological samples, IPP-based images lead to larger image contrast of some biological structures and to a further physical interpretation of the depolarizing mechanisms inherent to the samples.


Jueves, 4 de enero de 2018 Sin comentarios

New paper in Optical Engineering about parallel multiple imaging with a polarization diffraction grating


OptEngA new paper entitled Multichannel polarization imaging with a polarizing diffraction grating has been published in Optical Engineering. The work has been done in collaboration with our friends at the Department of Physics at San Diego State University (SDSU).

The work demonstrates a method to generate multiple imaging with polarization state diversity, based on the use of  a polarization diffraction grating design. The polarization grating is demonstrated in an SLM-based optical system developed at SDSU. We demonstrate the generation of six diffraction orders that encode six different polarization transformations. This technique can be useful for producing single-shot imaging polarimeters.

 

 


Viernes, 10 de noviembre de 2017 Sin comentarios

New paper in Optics Express about dual polarization split lenses


OptExpressWe published a new paper in Optics Express where we report the realization of polarization sensitive split lens configurations. We propose and demonstrate the generalization of the split lens concept to vectorial split lenses, leading to light patterns with customized intensity and state of polarization. We demonstrate how these polarization split lenses can be experimentally implemented by means of an optical system using two liquid crystal spatial light modulators, each one phase modulating one orthogonal polarization component.

The proposed technique is a simple method to generate structured light beams with polarization diversity, with potential applications in polarimetry, customized illuminators or quantum optics.

This work has been published in Optics Express, entitled Dual polarization split lenses. The work has been developed in collaboration with our friends at the Departamento de Ciencias Físicas, Universidad de la Frontera (Chile) and our friends at Departamento de Física de la Universitat Autònoma de Barcelona. This is the third paper resulting from the Thesis of the PhD student Aarón Cofré.


Martes, 19 de septiembre de 2017 Sin comentarios

María del Mar Sánchez gives a talk on q-plates at the Meeting of the Royal Spanish Physical Society


RSEFMaría del Mar Sanchez gave a talk about the generation of vectors beams with q-plate devices at the Meeting of the Royal Spanish Physical Society held in Santiago de Compostela in July 2017, 17th-21st, within the Symposium of Quantum & Non-linear Optics.

In this presentation, Maria del Mar reviewed some of our recent works. In the first part of the talk she presented the  performance of q-plates, and their combination to build other effective q-plates. In the second part she described the  implementation of q-plates on spatial light modulators, as well as their combination with axicon elements to create vector Bessel beams where both the topological charge and the polarization state vary upon propagation.


Categories: Collaborators, Conferences, Research Tags:

Jueves, 31 de agosto de 2017 Sin comentarios

Marcos Maestre presents his Final Degree Project on a system to control light pulses and measure slow and fast light


IMG_7139On Friday July 7th, Marcos Maestre, student of Telecommunications Engineering, has defended his Final Degree Project entitled “Control de Pulsos Ópticos en Fibra y Medida de Efectos de Luz Lenta y Luz Rápida en Interferómetros“.

In this work, an instrumental system and its control software has been developed in order to characterize electro-optical modulators and polarization interferometers based on birefringent fibers. Using this setup slow and fast light (SFL) effects have been demonstrated for optical pulses centered at 1550 nm.

The project, which has been supervised by Julia Arias and María del Mar Sánchez-López, has obtained the maximum qualification, with honours.

A related communication will be presented at OPTOEL2017 – the Spanish Meeting on Optoelectronics.


Categories: Education, Research, Students Tags:

Domingo, 23 de julio de 2017 Sin comentarios

Pascuala García presents an SLM based optical microscope at the SPIE Optical Metrology Conference in Munich


SPIE PasPascuala Garcia presented the communication entitled “On axis programmable microscope using liquid crystal spatial light modulator” at the SPIE Optical Metrology Conference, held in Munich in June 25th to 29th, 2007.

In her presentation, she showed an optical microscope system we have developed, that includes an LCOS SLM display to perform opto-digital filtering on-axis. We use a Hamamatsu SLM, free of flickering, which can be tuned to fully eliminate the zero order component of the encoded diffractive filter, therefore making use of the full space-bandwidth. The system was demonstrated by implementing different optical processing operations based on phase-only gratings such as phase-contrast, band-pass filtering, additive and subtractive imaging, or Differential Interference Contrast (DIC) imaging.

A related manuscript is available at the SPIE Proceedings in Optical Methods for Inspection, Characterization, and Imaging of Biomaterials III, edited by Pietro Ferraro, Simonetta Grilli, Monika Ritsch-Marte, Christoph K. Hitzenberger, Proc. of SPIE Vol. 10333, 103330Q (2017). Link

 


Viernes, 21 de julio de 2017 Sin comentarios

New paper in Scientific Reports, with a polarization grating design for the section of vector beams


SciRep

We published a new paper in Scientific Reports entitled Vector Beam Polarization State Spectrum Analyzer. This work has been done with our friends at San Diego State University.

In this work we present a proof of concept for a vector beam polarization state spectrum analyzer based on the combination of a polarization diffraction grating (PDG) and an encoded harmonic q-plate grating (QPG). The result is a two-dimensional polarization diffraction grating that generates six different q-plate channels with topological charges from −3 to +3 in the horizontal direction, and each is split in the vertical direction into the six polarization channels at the cardinal points of the corresponding higher-order Poincaré sphere. Consequently, 36 different channels are generated in parallel.

We show that this system can be used as a vector beam polarization state spectrum analyzer, where both the topological charge and the state of polarization of an input vector beam can be simultaneously determined in a single experiment.

Download the paper here

 


Categories: Collaborators, Publications, Research Tags:

Viernes, 26 de mayo de 2017 Sin comentarios

New paper in Journal of Biomedical Optics about a polarization gating method


JBOA new paper has been published in Journal of Biomedical Optics entitled Polarization gating based on Mueller matrices.

This work has been developed at the Department of Physics of the Autonomous University of Barcelona, with the participation of Ignacio Moreno.

It demonstrates a polarization gating method based on the experimentally measured Mueller matrices. Polarization gating refers to a collection of imaging methods based on the combination of different controlled polarization channels. Here, first the Mueller matrix is characterized, and then employed to evaluate different polarization channels. The methodology is applied on different biological samples.

 


Martes, 16 de mayo de 2017 Sin comentarios

Prof. Kristiaan Neyts visits TecnOpto-UMH


We were very pleased that Prof. Kristiaan Neyts, Head of the Liquid Crystals and Photonics Group from the Ghent University, accepted our invitation to come to Elche and impart a seminar on liquid crystals in the frame of the 3rd TECNIT PhD Workshop of our university, held in March 29th.

You can access to his seminar  LIQUID CRYSTALS: ROTATING MOLECULES FOR TUNABLE OPTICS here:


Martes, 11 de abril de 2017 Sin comentarios