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New paper in JEOS-Rapid Pub with an optical system to characterize retarders in a wide spectral range


jeosWe published a new paper in Journal of the European Optical Society – Rapid Publications, entitled Optical system for measuring the spectral retardance function in a extended range.

Here we apply a well-known technique for determining the spectral retardance of different linear retarders by measuring the transmission spectra between crossed or parallel polarizers. The system we developed allows measurements in a wide spectral range covering the visible (VIS) and near infrared (NIR) spectrum in the range from 400 to 1600 nm.

This work was made in collaboration with our friend Asticio Vargas from UFRO (Chile), and it is the first paper of the PhD thesis of Abdelghafor Messaadi.


Categories: International, Publications, Students Tags:

Lunes, 14 de noviembre de 2016 Sin comentarios

New paper in JJAP demonstrating the parallel generation of different vector beams


jjapWe published a new paper in Japanese Journal of Applied Physics entitled Parallel generation of multiple first-order vector beams with a polarization grating and a q-plate device.

In this work we demonstrated the parallel generation of multiple vector beams by combining a polarization diffraction grating with a q-plate element.

This work was made with our friends at San Diego State University (US), and in collaboration with our colleagues at the Development Division of Citizen Holdings Co (Japan).


Miércoles, 9 de noviembre de 2016 Sin comentarios

New paper in Optics Letters about the production of non-diffracting vector beams


Vector beamsWe published a new paper in Optics Letters, entitled Nondiffracting vector beams where the charge and the polarization state vary with propagation distance. The paper appeared published in the OL issue of May 2016.

In this work we  generate nondiffracting vector beams where the charge and the polarization state vary with the propagation distance. We use reflective geometry where a parallel-aligned spatial light modulator is used to spatially modulate two orthogonal linear polarizations. We encode spiral phases with equal charge but with opposite signs onto the two polarization directions to encode a vector beam and add two axicon phases. Both the charge and the phase shift between the two axicons can be varied along the focus line.

This work has been done in collaboration with our friends at San Diego State University, and was designed during the recent visit of Ignacio Moreno to SDSU in February 2016.


Categories: International, Publications Tags:

Miércoles, 18 de mayo de 2016 Sin comentarios

New paper in Optical Engineering, with a q-plate operating at the 1550 nm telecom wavelength


1550 nm peakWe published a new paper in Optical Engineering Letters, entitled Generation of vector beams at 1550 nm telecommunications wavelength using a segmented q-plate. The paper appeared published in the third issue of OE journal in 2016.

In this work we present the use of a q-plate device operating at the 1550 nm telecommunications wavelength. A prototype liquid-crystal device from Citizen Holdings Co. is demonstrated to be useful for the generation of vector beams and orbital angular momentum transfer at this important wavelength.

The device was developed for a visible wavelength, but we show here that it can be applied also for the 1550 nm wavelength, where is of interest to apply such devices to multiplex data with OAM channels.

This work was initiated during the stay of María M. Sanchez-López and Ignacio Moreno at SDSU during Summer 2015.


Categories: International, Publications Tags:

Sábado, 9 de abril de 2016 Sin comentarios

Ignacio Moreno presents an invited conference at SPIE Photonics Europe 2016


epeIgnacio Moreno presents an invited communication at the meeting SPIE Photonics Europe held in Brussels in April 2016.

The communication is entitled “Production of arbitrary polarized light beams with a liquid crystal spatial modulator”, and it was presented within the session Optical Micro- and Nanometrology. This communication reviews our recent advances in the design of polarization diffractive optical elements encoded onto a spatial light modulador system.


Categories: Conferences, International, Publications Tags:

Sábado, 9 de abril de 2016 Sin comentarios

The paper “Nondiffracting Bessel beams with polarization state that varies with propagation distance” selected by OSA for SPOTLIGHTS ON OPTICS


SpolightThe paper Nondiffracting Bessel beams with polarization state that varies with propagation distance that we published in Optics Letters last year has been selected in the section SPOTLIGHT ON OPTICS by OSA – the Optical Society of America, specifically in the section devoted to Optical Design and Instrumentation.

This section of the OSA website selects highlighted articles from OSA journals. Our paper in Optics Letters has been receiving considerable impact, since it was for three consecutive months in the TOP10 downloaded papers in the journal.

 


Categories: International, Outreach, Publications Tags:

Jueves, 7 de abril de 2016 Sin comentarios

New paper in Optics Letters with q-plates encoded onto a SLM to produce integer and fractional vector beams


ThumbnailWe published a new paper in Optics Letters entitled Generation of integer and fractional vector beams with q-plates encoded onto a spatial light modulator. The paper appeared published in the sixth issue of OL in 2016.

In this paper we generated programmable vector beams with arbitrary -plates encoded using a spatial light modulator system. Consequently, we have been able to analyze new and exotic -plate designs without the difficulty of fabricating individual plates. For instance, we showed experimental results for positive and negative integer and new fractional vector beam values.

For instance, the picture shows a fractional vector beam where the polarization changes linearly in three sectors along the polar coordinate in the plane traversal to the beam.

This work has been done during the stay of María M. Sanchez-López and Ignacio Moreno at SDSU during Summer 2015.


Martes, 22 de marzo de 2016 Sin comentarios

Ignacio Moreno writes about polarization of light in the FECYT educational unit devoted to light science


portada_unidad_d_luzIgnacio Moreno wrote the chapter entitled “Polarization of Light” in the didactic unit entitled Ciencia con Luz Propia: Aplicaciones Tecnológicas de la Luz (Science with its own Light: Technological Applications of Light).

This book has been published by FECYT – Fundación Española de Ciencia y Tecnología (Spanish Foundation for Science & Technology) and SM editorial, and can be free downloaded at the following link.

The book has been coordinated by Prof. José Antonio García, from the Department of Optics of the University of Granada, and it includes 10 chapters intended to provide tools about optics and light science for students at secondary schools, and promote the students’ interest in science and technology.

 

 


Categories: Education, Outreach, Publications Tags:

Domingo, 13 de marzo de 2016 Sin comentarios

New paper in Optics Express – Diffraction gratings generating orders with selective states of polarization


Optics ExpressWe published a new paper in Optics Express. The paper, entitled “Diffraction gratings generating orders with selective states of polarization” appears in the second issue of the journal in 2016.

In this paper we propose specially designed double anisotropic polarization diffraction gratings capable of producing a selective number of diffraction orders and with selective different states of polarization. Different polarization diffraction gratings are demonstrated, including linear polarization with horizontal, vertical and ± 45° orientations, and circular R and L polarization outputs. When illuminated with an arbitrary state of polarization, the system acts as a complete polarimeter where the intensities of the diffraction orders allow measurement of the Stokes parameters with a single shot. Experimental proof-of-concept is presented using a parallel-aligned liquid crystal display operating in a double pass architecture.

This work has been done in collaboration with our friends at San Diego State University.


Miércoles, 2 de marzo de 2016 Sin comentarios

New paper in Optics Letters – Analysis of a q-plate in a reflection geometry to double the q-value


IMagen

We published a new paper in Optics Letters entitled “Performance of a q-pate tunable retarder in reflection for the switchable generation of both first- and second-order vector beams“. The paper appeared published in the first issue of OL in 2016: link

Here we examine the performance of a tunable liquid crystal q-plate in a reflective geometry. When the device is tuned to a half-wave retardance, it operates as a q-plate with twice the value (2q) by adding a quarter-wave retarder between the mirror and the q-plate. However, when the device is tuned to a quarter-wave retardance, it acts as the original q-plate without the retarder. We show experimental results are shown. Using an input tunable polarization state generator, the system allows the switchable production of all states on both the first- and second-order Poincaré spheres.

This work has been done during the stay of Maria M. Sanchez-López and Ignacio Moreno at SDSU during Summer 2015.


Categories: International, Publications Tags:

Martes, 2 de febrero de 2016 Sin comentarios