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Special Section in Optical Engineering about Spatial Light Modulators


A special section on Spatial Light Modulators (SLMs) – Devices and Applications will be published in the journal Optical Engineering. Ignacio Moreno and María Del Mar Sanchez-Lopez are Guest Editors of this special section of the journal, together with Prof. Andrew Forbes and Prof. Yoshio Hayasaky.

The following link leads to the journal Call for Papers.

The deadline for submitting papers is September 15th, 2019. See here the flyer of the OE special section on SLMs. OE-SLMs

 


Miércoles, 14 de agosto de 2019 Sin comentarios

Maria del Mar Sanchez-Lopez visits GROC-UJI


D_3CUaiXoAA3s9lMaría del Mar Sánchez-López visited the Group of Optics of the University Jaume I de Castellón (GROC-UJI) to participate as a member of the jury of the Doctoral Thesis of Yessenia Jauregui Sanchez, supervised by Prof. Jesús Lancis and Prof. Enrique Tajahuerce.

Excellent work on single-pixel cameras and imaging through scattering media!

 


Categories: Research, Thesis Tags:

Sábado, 20 de julio de 2019 Sin comentarios

David Marco and Julio César Quiceno present their results at IONS 2019, Barcelona, June 2019


In his talk entitled “Two-dimensional geometric phase vortex grating based on the optimal triplicator design”, David presented the design and characterization of a liquid-crystal geometric phase diffraction grating that generates 3×3 diffraction orders with vortex beams of different topological charges, and showed the operation of this grating as a vortex detector. These results have recently been published in Optics Express: link to the paper.

Julio César presented a poster entitled “Hybrid vector beams generated by cascaded q-plates” where he demonstrated a q-plate-based optical system capable of generating a variety of hybrid vector beams, and showed the rotation of their polarization pattern when comparing the near field and the far field captures. This optical system is more compact than those based on SLMs whilst bearing a notable degree of versatility.

They have enjoyed the interesting conferences, scientific discussions and networking opportunities of this conference hosted by the OSA student chapter at ICFO and backed by the International OSA Network of Students. Link to the conference.

IONS

 

 


Domingo, 7 de julio de 2019 Sin comentarios

New paper in Optics Letters on breaking the Nyquist limit for diffractive lenses with high phase modulation displays


OL FIGWe published a new paper in Optics Letters entitled Encoding lenses with focal lengths lower than the Nyquist limit using high phase-modulation displays. In this work we show that focal lengths much lower than the classical Nyquist limit can be encoded onto spatial light modulators having a large phase-dynamic range.

Experimental results are included with a display showing 10π phase modulation reducing the Nyquist limit by a factor of about 1/10. We used a  Hamamatsu reflective LCoS device designed for use in the near infra-red (NIR) range, but operated with visible light in order to achieve such large modulation regimes.

The work has been done in collaboration with our friends at the Department of Physics of San Diego State University.


Jueves, 27 de junio de 2019 Sin comentarios

Carlos Hernandez seminar about Ultrafast Structured Laser Pulses


Carlos Hernandez2One day after the International Day of Light, Dr. Carlos Hernandez Garcia from USAL gave a seminar at TecnOPTO about Ultrafast Structured Laser Pulses – Extreme-Ultraviolet Vortex Beams Carrying Spin and Orbital Angular Momentum.

A great talk and a great discussion after the talk.


Categories: Research Tags:

Viernes, 17 de mayo de 2019 Sin comentarios

New paper in Optics Express about a geometric phase vortex triplicator grating


REDWe published a new paper in Optics Express entitled Optimal triplicator design applied to a geometric phase vortex grating. It shows a liquid-crystal diffraction grating based on the optimal triplicator design fabricated as a geometric phase element. We analyze the polarization properties of this special diffraction grating and then use embedded spiral phases to design geometric phase vortex diffraction gratings. The fabrication of a two-dimensional version of such a design is demonstrated using a micro-patterned half-wave retarder, where the phase distribution is encoded as the orientation of the fast axis of the retarder.

This proof-of-concept element is made of liquid crystal on BK7 substrate where the orientation of the LC is controlled via photoalignment, using a commercially available fabrication facility. Experimental results demonstrate the parallel generation of vortex beams with different topological charge and different states of polarization.

This work is part of the PhD Thesis of David Marco, and it has been done in collaboration with our friends Aarón Cofré and Asticio Vargas, from Universidad de La Frontera, Temuco, Chile.


Categories: Projects, Publications, Research, Thesis Tags:

Lunes, 6 de mayo de 2019 Sin comentarios

New paper in J. Opt. Soc. Am. B about the colors of a tunable q-plate


DzexHWoW0AAiN98Our new paper in Journal of the Optical Society of America B is entitled Using birefringence colors to evaluate a tunable liquid-crystal q-plate. Here we show a tunable liquid-crystal commercial -plate from the company Arcoptix, operative in the visible and near-IR range. We study its spectral and color birefringence properties under broadband illumination.

We first characterize the spectral retardance function of the device in a wide range from 400 to 1600 nm and determine how it changes upon applied voltage.

Then we evaluate the color transmission characteristics when inserting the -plate between crossed and parallel linear polarizers. These color properties agree with the trajectory in the CIExy chromaticity diagram as the applied voltage changes.

Finally, we demonstrate that a simple visual inspection of the transmitted birefringence color perceived when placing the -plate between crossed polarizers can be used to obtain a rapid estimation of the -plate retardance at given wavelength ranges.

This work is the first paper of the PhD Thesis of David Marco.


Categories: Projects, Publications, Research, Students, Thesis Tags:

Miércoles, 13 de febrero de 2019 Sin comentarios

Julio César Quiceno, from Universidad del Valle, Cali, joins TecnOpto


Dyz6KvlU8AAYqsiJulio César Quiceno, from Universidad del Valle, Cali, Colombia, will be visiting researcher at TecnOpto for a period of six months.

We will be working together in new projects related to vector beams.

Welcome to Elche!

 


Miércoles, 13 de febrero de 2019 Sin comentarios

New paper in Optics Express about Guoy phase effects on the propagation of vector beams


GuoyOur new paper in Optics Express entitled Gouy phase effects on propagation of pure and hybrid vector beams reports a theoretical simplified model and experimental analysis of the Gouy phase effects on vector beams. Experimental results at various axial planes, before and past the focus, are obtained by using a simplified liquid-crystal spatial light modulator-based optical system that allows the easy generation of these beams. Furthermore, a new alternative optical set-up that is devoid of moving elements is demonstrated, which simplifies this study.

We experimentally verify the differences between pure and hybrid vector beams upon propagation. While the first ones remain stable, hybrid vector beams show Gouy phase effects that demonstrate an optical activity where the local polarization states rotate by an angle that depends on the propagation distance.

This study has been conducted in collaboration with our friends at San Diego State University, Prof. Jeffrey A. Davis and Prof. Don M. Cottrell.


Martes, 29 de enero de 2019 Sin comentarios

New paper in Optical Engineering about a holographic projection system


OEng2A new paper of ours is published in the journal Optical Engineering entitled Holographic projection system with programmable control of state of polarization, focus plane, and size of the reconstruction

This work presents a holographic projection system based on the encoding of computer-generated holograms onto a spatial light modulator. We show how the size, location, and polarization state of the output can be controlled completely electronically, without physically moving any element in the system. And we show that the system is capable to produce optical logical operations by superimposing two different images encoded onto orthogonal polarization states.

The work has been done with our friends at the Department of Physics at San Diego State University.

 


Jueves, 27 de diciembre de 2018 Sin comentarios