Archivo para la categoría ‘Collaborators’ XML Feed

New paper in OLEN about a new method to obtain optical correlation

CorrelationOur last work is published in the journal Optics & Lasers in Engineering, entitled Multiple-order correlations and convolutions using a spatial light modulator with extended phase range. Here we present a new type of optical convolver / optical correlator capable of encoding multiple such operations. The technique is based on obtaining higher powers of a properly designed hologram. This can be obtained in two ways. First, we can recalculate higher powers of the amplitude and phase hologram in a standard spatial light modulator (SLM). Alternatively, we can utilize a phase-only hologram and exploit the properties of an SLM with extended phase modulation range.

The work has been done in collaboration with our colleagues Prof. Jeffrey A. Davis and Prof. Don M. Cottrell, and with Benjamin Gutierrez, from San Diego State University.

Viernes, 16 de julio de 2021 Sin comentarios

New paper in Scientific Reports about generating customized depolarizated spatial light patterns

Fig SCI REPIn our recent paper in Scientific Reports entitled Customized depolarization spatial patterns with dynamic retardance functions we demonstrate a proof-of-concept of a dynamical time-dependent pixelated retarder used to emulate a controlled spatially variant depolarizing sample.

We apply an imaging Mueller polarimetric system based on a polarization camera to verify the effective depolarization effect, and the effective depolarizance results are fully described within a simple graphical approach and standard Mueller matrix decomposition methods. The technique is illustrated by means of three practical cases, including exotic structures as a spirally shaped depolarization pattern.

The work has been done in collaboration with our colleagues Angel Lizana and Juan Campos, from MIP Optilab Laboratory at the Department of Physics of Universitat Autònoma de Barcelona, in the frame of our common research project devoted to the development of advanced polarimetric systems.

This work is also part of the PhD Thesis of David Marco.

Lunes, 3 de mayo de 2021 Sin comentarios

David Marco stays one month at ALBA synchrotron

Foto2David Marco stayed for one month at ALBA synchrotron, where he collaborated in the implementation and calibration of a liquid-crystal on silicon spatial light modulator, to be used in a fluorescence microscope in one of the lines of ALBA.

David has worked with experienced reserchers of ALBA, Eva Pereiro, Dominique Heinis and Josep Nicolás.

This stay was performed within the frame of our common national research project, coordinated by Prof. Juan Campos at Universitat Autònoma de Barcelona (UAB). This project involves the Optical Metrology & Image Processing Laboratory (MIP-OptiLab), the ALBA – Laboratory of Optics and TecnOPTO Laboratory.

This stay is also part of David’s training and research development within his PhD Thesis in the TECNIT PhD Program at UMH.


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Miércoles, 24 de marzo de 2021 Sin comentarios

New paper in OSAC about a complex encoding with Nyquist diffraction gratings

CapturaA new paper is available at OSA Continuum entitled Encoding complex amplitude information onto phase-only diffractive optical elements using binary phase Nyquist gratings.

In this new workwe reexamine a simple technique for encoding complex amplitude information onto a phase-only SLM. The approach uses a two-dimensional checkerboard binary phase diffraction grating where the diffraction efficiency is spatially varied.

We provide evidence of the usefulness of the technique but also about the limitations imposed by the current LCOS technology, which do not allow fully exploiting their high resolution, affected by the fringing effect.

The work has been done in collaboration with our coleagues at San Diego State University, Prof. Jeffrey A. Davis, Prof. Don M. Cottrell and Everett Wolfe.


Viernes, 26 de febrero de 2021 Sin comentarios

New paper in Crystals with a polarimetric imaging of radial polarizers and q-plates


A new paper is available in the journal Crystals entitled Mueller matrix polarimetric imaging analysis of optical components for the generation of cylindrical vector beams, in a special issue of the journal devoted to Liquid Crystals Optical Devices.

In this work we perform a Mueller matrix imaging analysis of two commercial optical components usually employed to generate and manipulate vector beams—a radial polarizer and a liquid-crystal q-plate. These two elements generate vector beams by different polarization mechanisms—polarizance and retardance, respectively.

The quality of the vector beams relies on the quality of the device that generates them. For this purpose, we applied a customized imaging Mueller matrix polarimeter based on liquid-crystal retarders and a polarization camera. Experimental results were compared to the numerical simulations, considering the theoretical Mueller matrix.

This work was done in collaboration with our colleagues Angel Lizana and Juan Campos from the MIP-Optilab at Universitat Autònoma de Barcelona, in the frame of our coordinated national project.

Viernes, 18 de diciembre de 2020 Sin comentarios

New paper in Optics Letters about a new technique of measuring the LCOS backplane deformation

INT1A new paper is available in Optics Letters entitled Measuring the spatial deformation of a liquid-crystal on silicon display with a self-interference effect.

Here we present a simple technique to characterize the spatial non-uniformity of a LCOS-SLM, based on illuminating the display with a wavelength out of the operation range. In this situation there is a significant reflection at the output surface and a Gires–Tournois type interferometer is directly created, without any alignment requirement and insensitive to vibrations. The beam reflected at the output surface is the reference beam, while the beam reflected at the silicon backplane is modulated with the addressed gray level in order to quantitatively derive its deformation. We provide an experimental demonstration using a LCOS-SLM designed to operate in the near-infrared range but illuminated with visible light.

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

Viernes, 7 de agosto de 2020 Sin comentarios

FYLA interview with Ignacio Moreno

FYLA2FYLA is a young Spanish laser company. At TecnOPTO we have two of their supercontinuum lasers.

We use them in a variety of experiments that include the broadband characterization of optical retarders and iquid-crystal SLMs, and their use diffractive and optical information systems.

At the following link you can access the recent interview they made to Ignacio Moreno.

We thank Gaia Sardiello for her interview and collaboration.



Categories: Collaborators, Research Tags:

Viernes, 31 de julio de 2020 Sin comentarios

New paper in OSA Continuum about double ring interference with binary axicons

CbeltA new paper is available at OSA Continuum entitled Double-ring interference of binary diffractive axicons.

Here we report on the interference between the double rings generated by the Fourier transform of a binary diffractive axicon. These two rings have the same size and correspond to the +1 and -1 diffracted order beams. The interference condition between both rings can be easily changed by adding a constant phase bias. Additionally, this interference condition can be changed along the ring.

This work has been done in collaboration with our colleagues at San Diego State University Prof. Jeffrey A. Davis, Prof. Don M. Cottrell and Benjamin Gutierrez.

Lunes, 15 de junio de 2020 Sin comentarios

TecnOPTO organizes a workshop on ‘Structured Light, Polarimetry and Imaging’


On November 25th, 2019 we organized a workshop entitled ‘Structured Light, Polarimetry and Imaging‘.

The workshop was held at the Institute of Bioengineering of UMH, and we could count with the participation of experts from different groups in Spain working in these related fields. The program can be viewed at the following link.

We thank all the participants and attendees to this extremely interesting and motivating reunion.

Martes, 26 de noviembre de 2019 Sin comentarios

New paper in OLEN analyzing the diffraction efficiency of stepped gratings in large phase modulation SLMs

OLENOur new publication is available in Optics & Lasers in Engineering, entitled Diffraction efficiency of stepped gratings using high phase-modulation spatial light modulators.

We study the diffraction efficiency of linear phase (blazed) diffraction gratings displayed onto SLMs that exhibit a large phase modulation range, reaching a maximum phase modulation of 8pi or 10pi radians. We analyse these effects for their important implications in the Nyquist limit for diffractive elements

The paper has been done in collaboration with our friends at San Diego State University.

Domingo, 3 de noviembre de 2019 Sin comentarios