In this work we present a new configuration to achieve an achromatic all-optical Fourier transform (FT) using two blazed diffractive lenses and one non-dispersive lens. Different configurations are identified by imposing constraints on the ray matrix of the optical system, minimizing the wavelength dependence of both the transversal location of the FT plane and the FT spatial scaling.
Experimental verification is carried out using geometric-phase (GP) flat diffractive lenses and an achromatic refractive lens. Furthermore, one identified novel configuration is symmetric. This symmetric triplet configuration enables a straightforward implementation in a reflective geometry that reduces the number of elements to a single GP lens combined with a mirror, thus leading to a highly-compact implementation. Experimental results are presented that validate the proposed systems.
This work is part of the PhD Thesis of Santiago Ríos.
We have an open Junior Researcher position within the Project CIAICO/2024/273 of Generalitat Valenciana “Structured Light for Advanced Imaging Systems”.
Interested? Please contact: Prof. Ignacio Moreno () and provide CV and motivation letter Due date: 12th January 2026
Tasks involved: theoretical modeling, computer simulations and laboratory experiments within the following research lines:
Design and generation of structured light,
Spatial light modulators (SLM),
Microstructured optical components,
Polarimetric/ spectral imaging and polarization interferometry.
Characteristics:
Contract duration:12 months (renewable up to a maximum of 30 months)
Gross monthly salary:1700 € (approx)
Expected starting date: February-March 2026
Application requirements:
Degree/Master in Physics, Engineering, Computing, o rsimilar.
Background in optics or optoelectronics. Programming skills.
Our last article is published in the journal Optics & Lasers in Engineering, entitled Study of symmetry and retracing properties of geometric phase gratings and lenses. Here we analyze the symmetry properties of polarization sensitive geometric phase gratings and geometric phase lenses, and compare them with the regular scalar elements.
Experimental results are included that evidence these properties with simple optical arrangements. These include experiments where the gratings are used in a transmission configuration, and others where a mirror is added to analyze a counter-propagated beam.
Ignacio Moreno coauthored a recent review paper in Applied Sciences that describes the advances accomplished in the application of polarization metrics based on the Polarizance-Reflection-Transformatin (PRT) and the Indices of Polarization Purity (IPP) to to distinguish between non-depolarization systems.
He was member of the Scientific Advisory Board and he delivered the invited talk entitled ‘Fourier transform Jones matrix approach for polarized structured light’.
Ignacio Moreno was this year one of the General Chairs of the Annual Meeting of the European Optical Society, EOSAM2025, held in Delft (The Netherlands) in 24-28 August 2025.
Ignacio delivered again a tutorial on «Spatial Light Modulators» in collaboration with the company Holoeye Photonics.
After nearly three years with us, on July 23th 2025, Shang Gao made the defense of her PhD Thesis within the UMH Doctoral Program in Bioengineering.
We thank Prof. German Torregrosa, from UMH, Prof. Elisabet Perez-Cabré, from Universitat Politècnica de Catalunya and Prof. Angel Lizana, from Universitat Autònoma de Barcelona, members of the jury.
The Thesis, entitled Study of triplicator diffraction gratings and holograms displayed onto spatial lightmodulators, was supervised by María del Mar Sánchez-López and Ignacio Moreno.
Shang’s work led to the following compendium of articles:
In this work we extend the optimum phase triplicator diffraction grating profile to a phase-only hologram. This modified hologram generates three equally-energetic orders with the highest diffraction efficiency, yielding a direct version and an inverted complex conjugate version of the target pattern in the ±1st orders, respectively, and a delta function in the DC zero order. When combined with another phase-only function, the resulting hologram yields convolution and correlation terms in the ±1st orders, respec- tively, while the target function encoded in the added phase appears in the zero order. Experimental results obtained with a high-resolution liquid-crystal phase-only spatial light modulator (SLM) demonstrate the proposed design.
In this work we demonstrate how to generate quasi-monochromatic laser beams with engineered, non-uniform transverse spatial coherence properties using an unpolarized helium–neon laser. This is achieved with a static phase modulating device that spatially modulates the laser’s two orthogonal polarization components, followed by a linear polarizer.
We demonstrate the method wih patterned geometric phase elements or and with programmable liquid-crystal spatial light modulators. The technique exploits the nanosecond-timescale variation of the laser’s emitted polarization ellipse, creating configurable non-uniform coherence patterns that maintain their spatial coherence characteristics down to nanosecond temporal windows.
This work has been leaded by David Marco during his postdoctoral stay at TecnOpto Lab during 2024.
Ignacio Moreno delivered the talk entitled «Digital control of light beams with spatial light modulators 1: liquid crystal displays» on June 3rd. The next day, Pascuala García delivered the talk «Gender perspective and equality in research».
We are grateful to our colleagues at UJI for the invitation and hospitality.
Our recent paper published in Journal of Physics – Photonics is entiled Compact achromatic optical Fourier transform system using geometric-phase lenses.
