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New paper in OLT with a new polarization grating based single shot polarimeter


OLTWe developed a quantitative analysis of the performance of a complete snapshot polarimeter based on a polarization diffraction grating (PDGr). The work has been published in the paper entitled Quantitative performance of a polarization diffraction grating polarimeter encoded onto two liquid-crystal-on-silicon displays, published at the journal Optics & Laser technology.

The PDGr is generated in a common path polarization interferometer with a Z optical architecture that uses two liquid-crystal on silicon (LCoS) displays. The programmable PDGr is capable to act as a simultaneous polarization state generator (PSG), yielding diffraction orders with different states of polarization. The same system is also shown to operate as a polarization state analyzer (PSA), therefore useful for the realization of a snapshot polarimeter. We analyze its performance using quantitative metrics such as the conditional number.

This 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. And it will part of the PhD Thesis of Aarón Cofré.


Miércoles, 14 de junio 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

New paper in Journal of Optics about Solc filters in a reflective geometry


JOpticsWe published a new paper in Journal of Optics entitled Solc filters in a reflective geometry. It presents the realization of  birefringent Solc type filter in a reflective geometry.

This geometry reduces by half the number of required retarders, ensures the same spectral retardance function in pairs of retarders. The key element is a quarter-wave Fresnel rhomb located in between the set of retarders and a mirror. We present two cases, one with multiple-order quartz retarders, and a second one that uses two liquid-crystal retarders, this last one being therefore tunable.

This is the second paper in the PhD Thesis of Abdelgahfour Messaaddi, and it has been done in collboration with our friend Asticio Vargas form Universidad de La Frontera , Temuco (Chile) and our friend Noureddine Bennis and his coworkers at the Military University of Technology, Warsaw (Poland).


Jueves, 16 de marzo de 2017 Sin comentarios

New publication in Applied Optics about the arithmetics of q-plates


ArithmeticsA new paper entitled Arithmetics with q-plates was published in Applied Optics where we show the capability to form various q-plate equivalent systems using combinations of commercially available q-plates. We show operations like changing the sign of the q-value, or the addition and subtraction of q -plates. These operations only require simple combinations of q-plates and half-wave plates.

This work was developed in collaboration with our friends at San Diego State University.


Categories: International, Publications, Research Tags:

Domingo, 22 de enero de 2017 Sin comentarios

New paper in Optics & Laser in Engineering about a digital microscope with programmable Fourier transform filtering


olenWe published a new paper in the journal Optica & Lasers in Engineering about a digital microscope with programmable Fourier transform filtering. The paper is entitled Microscope system with on axis programmable Fourier transform filtering and was developed by Jose Luis Martínez, Pascuala Garcia and Ignacio Moreno.

In this work we demostrate such opto-digital filtering on-axis, taking advantage of phase and polarization modulation of a LCOS-display. 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 is  demonstrated by implementing different optical processing operations based on phase-only gratings such as phase-contrast, band-pass filtering, or additive and subtractive imaging. A simple Differential Interference Contrast(DIC) imaging is also obtained changing to a polarization modulation scheme.

A proposal related to this work was selected as finalist on the 2016 Educational Award by Edmund Optics.


Categories: Publications, Research Tags:

Domingo, 8 de enero de 2017 Sin comentarios

New paper describing the Women in Light Sciences and Light Technologies Exhibition in RdF


rdfA new paper entitled Investigadoras en la luz y en las tecnologías de la luz (Women in Light Sciences and Light Technologies) has been published in the Revista Española de Física (Spanish Journal of Physics).

This paper describes the exhibition with the same name that was developed to commemorate the International Year of Light, describing the life and work of 12 women that made relevant contributions to the science of light.

This paper was written by Maria del Mar and Pascuala, in collaboration with Ana J. López-Díaz, from Universidade da Coruña, and Augusto Beléndez, from Universidad de Alicante.


Sábado, 17 de diciembre de 2016 Sin comentarios

New paper in Applied Optics about a new optical encryption technique


ao2017A new paper has been published in Applied Optics entitled New key based on tilted lenses for optical encryption, that describes a novel concept based on tilted spherical lenses for optical encryption using Lohmann’s type I systems. An experiment is presented, considering a hybrid encryption/decryption process where the image is numerically encrypted but optically decrypted.

This work was developed by our friends at the University of Valencia and we contributed by developing a experimental system that demonstrates the procedure.

 


Jueves, 15 de diciembre de 2016 Sin comentarios

New paper in European Journal of Physics about vortex beams with a TNLC-SLM


ejpWe published a new paper in European Journal of Physics entitled Vortex beam generation and other advanced optics experiments reproduced with a twisted-nematic liquid-crystal display with limited phase modulation.

In this work we propose the use of twisted-nematic liquid-crystal spatial light modulators (TN-LC-SLM) as a useful tool for training students in the manipulation of light beams with phase-only masks. In particular, we focus the work on the realization of phase-only gratings and phase-only spiral phases for the generation of vortex beams, beams carrying orbital angular momentum (OAM). We include different examples, including a optimal triplicator phase grating, and its combination with spiral phase patterns and lens functions to generate a variety of vortex beams.

The paper is included in a special section of the journal devoted to “Advanced Optics”, and it is the first publication from the PhD Thesis of Aarón Cofré.


Categories: Education, International, Publications Tags:

Miércoles, 14 de diciembre de 2016 Sin comentarios