Events and congress

Participation of the ALF USAL Group in RNO2024

The ALF USAL group had a prominent participation in the XIV National Optics Meeting and the V National Young Optics Meeting (RNO2024) held from July 2 to 5 in Murcia, Spain.

This event, which brings together leading experts and young talents in the field of optics, has been an exceptional platform to present the latest advances in research and development in this field.

The group contributed with a series of works that address various areas of modern optics, standing out for their innovation and scientific rigor. The presented works are summarized below:

Attosecond Structured Light (Invited)
Autor: Hernández García, C.
Diseño de guías de ondas superficiales optimizadas para sensado y extracción de luz en materiales cristalinos fabricadas mediante escritura directa con láser de femtosegundo (Oral)
Autores: Arroyo Heras, V., López Quintas, I., Vázquez De Aldana, J. R., Bonduelle, M., Martín, G., & Romero Vázquez, C.
Medida de pulsos ultracortos vectoriales con amplitude swing (Oral)
Autores: Barbero, C., Alonso, B., & Sola Larrañaga, I. J.
Towards an all-fiber source of isolated attosecond pulses driven by high-energy sub-cycle waveforms from soliton dynamics (Oral)
Autores: Fernández Galán, M., Serrano, J., Conejero Jarque, E., Borrego-Varillas, R., Lucchini, M., Reduzzi, M., Nisoli, M., Brahms, C., Travers, J. C., Hernańdez-García, C., & San Román, J.
Sistema óptico aplicado a la espectroscopía resuelta en tiempo en el rango de femtosegundo y picosegundo (Oral)
Autores: Guerras, M., Lópe Quintás, I., & Sola Larrañaga, I. J.
Intense and isolated polarization-controlled magnetic fields from structured laser beams to drive nonlinear magnetization dynamics (Oral)
Autores: Martín Domene, S., Sánchez-Tejerina, L., Martín-Hernández, R., & Hernández García, C.
Generation of extreme-ultraviolet high-topological charge spatiotemporal optical vortices (Oral)
Autores: Martín-Hernández, R., Gui, G., Plaja, L., Kapteyn, H. C., Murnane, M. M., Liao, C.-T., Porras, M. Á., & Hernandez-Garcia, C.
Self-interference of Hermite-Gaussian high-order harmonics simulated through machine learning (Oral)
Autores: Pablos-Marín, J. M., Schmidt, D., De Las Heras, A., Westlake, N., Serrano, J., Lei, Y., Kazansky, P., Adams, D., Durfee, C., & Hernández García, C.
Topological spectroscopy: High Harmonic Generation from Graphene irradiated by structured fields (Oral)
Autores: Plaja, L., García Cabrera, A., Boyero-García, R., Zurrón-Cifuentes, O., Serrano, J., San Román, J., & Hernández-García, C.
Improving pulse self-compression in photonic crystal fibers using particle swarm optimization algorithm. (Oral)
Autores: Vaquero, A., Galán, M. F., Rodríguez Frías, M. D., Conejero Jarque, E., & Méndez, C.
Macroscopic simulations of high-order harmonic generation assisted by artificial intelligence. (Oral)
Autores: Serrano, J., Pablos-Marín, J. M., & Hernández García, C.
Clean Temporal Pulses from All-Bulk Multipass Cells. (Oral)
Autores: Segundo-Staels, V., Conejero Jarque, E., & San Roman, J.
Microscopía de generación de segundo armónico en cristales microestructurados con pulsos de femtosegundo: BBO y Nd:YAG. (Oral)
Autores: Sevilla-Sierra, N., Rodríguez Vázquez de Aldana, J., Romero Vázquez, C., Mateos, X., & López Quintas, I.
PW-class laser spatio-temporal characterization (Póster)
Autores: Barbero, C., García-García, E., Mendez, C., Rodríguez Frias, M. D., López-Ripa, M., Sola Larrañaga, I. J., & Alonso Fernández, B.
Fabricación de dispositivos fotónicos funcionales mediante escritura directa con láseres de femtosegundo. (Póster)
Autores: Romero Vázquez, C., Arroyo Heras, V., Sevilla Sierra, N., López Quintás, I., & Vázquez De Aldana, J. R.

In addition to presenting their work, the researchers from the ALF USAL group also contributed to the conference by moderating several oral communication sessions:

Luis Plaja, moderator of the Quantum and Nonlinear Optics session on Wednesday, July 3
Carlos Hernández García, moderator of the Quantum and Nonlinear Optics session on Thursday, July 4

These works reflect the ALF USAL group’s commitment to scientific excellence and their ability to lead in the field of optical research. The diversity and depth of their studies presented at RNO2024 underscore their crucial role in advancing modern optics.

8 July, 2024 admin ALF results, Events and congress No comments

Participation in the XVII National Congress on Materials CNMAT24

We are pleased to announce that three researchers from the Laser Applications and Photonics Group at the University of Salamanca have participated in the XVII Edition of the National Congress on Materials (CNMAT24). The congress took place from June 25 to 28, 2024, in the city of Málaga and brought together national and international experts in the field of materials.

Researchers Pablo Moreno Pedraz, Javier Rodríguez Vázquez de Aldana, and Ignacio López Quintás presented their latest work at this prestigious event, highlighting advancements and innovative applications in the field of photonics and laser technology.

Javier Rodríguez Vázquez de Aldana participated as the moderator of the Laser Material Processing symposium and also presented the poster titled “Microstructuring of transparent crystalline materials with ultrashort pulse lasers: new developments and applications.”
Pablo Moreno Pedraz presented the work titled “Influence of the substrate and thickness on the formation of LIPSS in thin polymer films.”
Ignacio López Quintás presented the work titled “Second harmonic generation in Nd crystals microstructured by laser.”

The participation of our researchers in CNMAT24 not only reinforces our group’s position at the forefront of scientific research but also demonstrates our continuous commitment to excellence and innovation in the field of photonics and laser technology.

Congratulations to Pablo, Javier, and Ignacio for their outstanding contribution and for representing our group and the University of Salamanca so well at this important event!

28 June, 2024 admin ALF results, Events and congress No comments

PARTICIPATION OF RESEARCHERS FROM THE LASER AND PHOTONICS APPLICATIONS GROUP IN ICOAM2024

Researchers Carlos Hernández García and Rodrigo Martín-Hernández, members of the Laser and Photonics Applications Group and the ERC Attostructura project (851201), actively participated in the Seventh International Conference on Optical Angular Momentum. This prestigious conference took place from June 10 to 13, 2024, at Kruger National Park, South Africa.

The Seventh International Conference on Optical Angular Momentum (ICOAM 2024) is a prominent event in the field of optics and photonics, focusing on the study and applications of light’s angular momentum. This event gathers scientists and experts from around the world to discuss the latest advancements and share innovative research in areas such as particle manipulation, quantum optics, generation of angular momentum beams, and biomedical and communication applications.

Carlos Hernández García participated as an invited speaker with his work titled “Attosecond vortex pulse trains”.

The landscape of ultrafast structured light pulses has recently evolved thanks to the capability of high-order harmonic generation (HHG) to nonlinearly convert orbital angular momentum (OAM) from infrared to extreme-ultraviolet/soft X-rays. Up to now, HHG has been demonstrated to produce harmonic vortex pulses on the femtosecond scale through various studies, where higher-order harmonics exhibit distinct OAM content. This characteristic, a result of OAM conservation rules, has hindered the emission of vortex beams with attosecond pulse durations.

In this work, we demonstrate, both theoretically and experimentally, the generation of attosecond vortex pulse trains – a succession of light pulses each with a temporal duration of hundreds of attoseconds, and a similar helical wavefront. This achievement is realized by synthesizing a comb of high-order harmonics with identical OAM. To our knowledge, these are the first vortex pulses produced on the attosecond scale.

To achieve this, we drove HHG with an infrared bifurcated polarization tilt-angle grating, resulting from the non-collinear superposition of two counter-rotating circularly polarized beams with opposite OAM. The simultaneous conservation of linear momentum, spin angular momentum, and orbital angular momentum in the HHG process leads to two spatially-separated circularly polarized high-order harmonic beams with OAM independent of the order. Our work paves the way towards attosecond-resolved light-matter interactions at the natural timescale of electronic dynamics in atoms, molecules, or solids.

Rodrigo Martín-Hernández participated in the poster session with the work titled “How to generate spatiotemporal optical vortices in the extreme-ultraviolet/x-ray regime.”

The generation of spatiotemporal optical vortices (STOVs) in the near-infrared regime has been successfully studied in recent years, both theoretically and experimentally. However, their extension to higher-frequency regimes has not yet been demonstrated. Over the last decade, it has been shown that high-order harmonic generation (HHG) can successfully transfer longitudinal optical vortices from the near-infrared to the extreme-ultraviolet (EUV) and X-ray regimes. Following an immediate analogy, one might think that HHG driven by STOVs would result in high-frequency STOVs with high topological charge. However, this scenario offers much richer possibilities.

In this work, we explore the nonlinear conversion of STOVs from the near-infrared to EUV/X-rays using HHG. Depending on the driving beam configuration, we identify two scenarios that lead to strongly differentiated phenomena.

Firstly, if HHG is driven by a canonical, elliptical, single-charged STOV focused on a gas target, high-frequency harmonic STOVs with the same topological charge as the driving field are generated. Our theoretical calculations unequivocally demonstrate that this result depends heavily on the non-perturbative nature of the HHG process. Thus, these results not only provide harmonic combs of low-topological charge STOVs in the EUV/X-ray range but also open the door to investigating some of the most fundamental questions about the intrinsic non-perturbative nature of the HHG process.

Secondly, if the driving beam is designed to deliver a canonical (elliptical), single-charged STOV at the gas target, high-order harmonic STOVs with high topological charge are generated. We demonstrate that in this scenario, the resulting topological charge of the harmonic STOVs increases according to the harmonic order multiplied by the fundamental topological charge, following the same well-known conversion rule as in longitudinal optical vortices.

Carlos Hernández García and Rodrigo Martín-Hernández’s participation in ICOAM 2024 underscores the Laser and Photonics Applications Group’s commitment to cutting-edge research and international collaboration in the field of optics and photonics. Their work not only contributes to the advancement of scientific knowledge but also opens new opportunities for innovative technological applications.

28 June, 2024 admin ALF results, Attostructura_En, Events and congress No comments

Attostructura participates in Pint of Science 24

Carlos Hernández García, the principal researcher of the Attostructura project, will be part of the exciting Pint of Science24 event. This international festival, held annually in bars, pubs, and other informal venues across multiple countries around the world, offers a unique experience where scientists and researchers share their knowledge in engaging and accessible talks for all audiences.

During Pint of Science, the exchange of ideas flows in a relaxed and social atmosphere, aiming to bring science closer to society and foster dialogue between experts and the general public.

Don’t miss Carlos’ participation on May 13th with his fascinating talk “Life in a Trillionth of a Second,” starting at 8:00 PM at Manolita (C/ Palominos 21). An unmissable opportunity to explore the mysteries of our universe in an informal and enjoyable setting!

10 May, 2024 admin Events and congress, Scientific outreach No comments

Researchers from the ALF group at USAL participated in the HILAS congress

Researchers from the ALF group at USAL, including Carlos Hernández García, Marina Fernández Galán, and Rodrigo Hernández Martín, participated in the High-Intensity Lasers and High-Field Phenomena (HILAS) congress, which took place from March 12th to March 14th in Vienna.

HILAS serves as a prominent platform for scientists and researchers to explore cutting-edge advancements and discoveries in the field of high-intensity lasers and high-field phenomena. The congress provides a forum for discussions, presentations, and collaborations among experts in various disciplines, including physics, optics, engineering, and materials science. Through keynote speeches, panel sessions, and workshops, HILAS facilitates the exchange of knowledge and fosters innovation in this rapidly evolving field.

The following works have been presented:

Simulating Macroscopic High-order Harmonic Generation Driven by Structured Laser Beams Using Artificial Intelligence, Carlos Hernandez-Garcia; Universidad de Salamanca, Spain.

Compact Generation of Isolated Attosecond Pulses Driven by Self-compressed Subcycle Waveforms, Marina F. Galán¹, Javier Serrano¹, Enrique Conejero Jarque¹, Rocío Borrego-Varillas², Matteo Lucchini³, Maurizio Reduzzi³ , Mauro Nisoli³ , Christian Brahms⁴, John C. Travers⁴, Carlos Hernandez-Garcia¹, Julio San Roman¹; 1 Universidad de Salamanca, Spain; 2 IFN-CNR, Italy; 3 Politecnico di Milano, Italy; 4 Heriot-Watt University, United Kingdom.

We theoretically demonstrate a compact and robust scheme for the direct generation of extreme ultraviolet isolated attosecond pulses from high-order harmonics driven by self-compressed subcycle waveforms produced in a gas-filled hollow capillary fiber.

Generation of high-order harmonic spatiotemporal optical vortices, Rodrigo Martín Hernández^1,2, Guan Gui³, Luis Plaja^1,2, Henry K. Kapteyn³, Margaret M. Murnane³, Miguel A. Porras⁴, Chen-Ting Liao^3,5, Carlos Hernandez-Garcia^1,2; 1 Grupo de Investigación en Aplicaciones del Láser y Fotónica. Departamento de Física Aplicada, Universidad de Salamanca, Spain; 2 Unidad de Excelencia en Luz y Materia Estructuradas (LUMES), Universidad de Salamanca, Spain; 3 JILA and Department of Physics, University of Colorado and NIST, USA; 4 Grupo de Sistemas Complejos, ETSIME, Universidad Politécnica de Madrid, Spain; 5 Department of Physics, Indiana University, USA.

We theoretically and experimentally demonstrate the generation of high-topological charge, extreme-ultraviolet (EUV) spatiotemporal optical vortices (STOV) from high-order harmonic generation. EUV-STOVs are unique structured light tools for exploring ultrafast topological laser-matter interactions.

15 March, 2024 admin ALF results, Events and congress No comments

Researchers from the ALF USAL group attend the congress OPA 2023

Luis Plaja and Carlos Hernández García researchers from the Laser and Photonics Applications group (ALF – USAL) have attended and participated in the Optics & Photonics Africa OPA 2023 congress that took place from November 6 to 10 in White River – South Africa.

They presented the contributions titled:

Topological high-harmonic spectroscopy: observing matter response from the topology of the harmonic field.
Short Wavelength Structured Light for Attosecond Science

At this link you can consult the press release published by the International Commission for Optics with all the information about the congress.

13 November, 2023 admin Events and congress No comments

ALF-USAL researchers participate in the annual meeting of the European Optical Society (EOSAM 2022)

From September 12 to 16, the annual meeting of the European Optical Society (EOSAM 2022) was held in Porto (Portugal). The Laser and Photonics Applications group (ALF – USAL) has participated in this conference presenting some of the most recent results of the research it is currently carrying out.

The works presented were:

Marina Fernández Galán, Enrique Conejero Jarque, Julio San Román. Pulse self-compression down to the sub-cycle regime in hollow capillary fibers with decreasing pressure gradients. TOM 8 Non-linear and Quantum Optics – Oral contribution (Abstract).
Miguel López Ripa, Iñigo J. Sola, Benjamín Alonso. Ultraestable spatiotemporal characterization of optical vortices in the visible and near infrared. TOM 13 Advances And Applications of Optics and Photonics – Oral contribution (Abstract).
Rodrigo Martín Hernández, Luis Plaja, Carlos Hernández García. Fourier-limited attosecond pulse generation with magnetically pumped high-order harmonic generation. TOM 8 Non-linear and Quantum Optics – Oral contribution (Abstract)
Luis Plaja, Ana García Cabrera, Roberto Boyero-García, Óscar Zurrón, Julio San Román, Carlos Hernández García. Multi-beam vortex generation induced by the non-linear optical anisotropy of graphene. TOM 8 Non-linear and Quantum Optics – Poster (Abstract)
Victor W. Segundo Staels, Enrique Conejero Jarque, Daniel Carlson, Michaël Hemmer, Henry C. Kapteyn, Margaret M. Murnane, Julio San Román. Supercontinuum generation in the enhanced frequency chirp regime in multipass cells. TOM 8 Non-linear and Quantum Optics – Oral contribution (Abstract)
Carlos Hernández García. Novel ultrafast structured EUV/x-ray sources from nonlinear optics. TOM 13 Advances And Applications of Optics and Photonics – Oral contribution (Abstract).

25 October, 2022 admin ALF results, Events and congress, Scientific outreach No comments

ALF-USAL researchers participate in the XXXVIII Biennial Meeting of the Royal Spanish Society of Physics (Murcia)

From July 11 to 15, the XXXVIII Biennial Meeting of the Royal Spanish Society of Physics was held. The Laser and Photonics Applications group (ALF – USAL) has participated in said biennial, presenting some of the most recent results of the research it is currently carrying out.

The works presented were:

Luis Sánchez-Tejerina, Rodrigo Martín-Hernández, Rocío Yanes, Luis Plaja, Luis López-Díaz, Carlos Hernández-García. “Magnetic order excitation by magnetic fields from sub-picosecond structured laser pulses”. S15 Novel frontiers and challenges in magnetism – Oral contribution. (Abstract)
Rodrigo Martín-Hernández, Luis Sánchez-Tejerina, Enrique Conejero Jarque, Luis Plaja , Carlos Hernández-García. “Spatial isolation of femtosecond magnetic needles driven by azimuthally-polarized laser beams“, S15 Novel frontiers and challenges in magnetism – Oral contribution. (Abstract). Prize for the best oral contribution in the Symposium “Novel Frontiers and Challenges in Magnetism” awarded by the Spanish chapter of IEEE Magnetics.
Miguel López-Ripa, Íñigo J. Sola, Benjamín Alonso. “In-line and ultraestable spatiotemporal characterization of constant and time-varying optical vortices“, S9 Quantum Optics and Nonlinear Optics – Oral contribution (Abstract)
V. W. Segundo Staels, E. Conejero Jarque, J. San Roman. “Use of gas-filled multipass cells to generate clean supercontinuum spectra“, S9 Quantum Optics and Nonlinear Optics – Oral contribution. (Abstract)
Luis Sánchez-Tejerina, Rodrigo Martín-Hernández, Rocío Yanes, Luis Plaja, Luis López-Díaz, Carlos Hernández-García. “Non-linear, purely magnetic magnetization response to femtosecond structured laser pulses“, S9 Quantum Optics and Nonlinear Optics – Oral contribution. (Abstract)
Rodrigo Martín-Hernández,Luis Plaja, Carlos Hernández-García. “Magnetically-pumped High Harmonic Generation with circularly polarized driving fields”, S9 Quantum Optics and Nonlinear Optics – Oral contribution. (Abstract)
Ana García-Cabrera, Roberto Boyero-García, Óscar Zurrón Cifuentes, Julio San Román, Carlos Hernández-García, Luis Plaja. “Multi-vortex high-harmonic beams from graphene’s anisotropy“, S9 Quantum Optics and Nonlinear Optics – Oral contribution. (Abstract)
Alba de las Heras, Alok Kumar Pandey, Julio San Román, Javier Serrano, Luis Plaja. “Extreme-ultraviolet scalar and vectorial vortices with very high topological charge“, S9 Quantum Optics and Nonlinear Optics – Oral contributionl. (Abstract). Winner of the “Young Researchers” contest in the student category.
Ignacio Lopez-Quintas, Warein Holgado, Rokas Drevinskas, Peter G. Kazansky, Íñigo J. Sola, Benjamín Alonso. “Collinear optical vortices with tailored topological charge generated by angular momentum transfer“, S9 Quantum Optics and Nonlinear Optics – Poster. (Abstract)
Javier Serrano, Carlos Hernández-García. “High-performance simulations of high-order harmonic generation based on artificial intelligence“, S9 Quantum Optics and Nonlinear Optics – Poster. (Abstract)
Rosa Ana Pérez-Herrera, Alba de las Heras, María-Baralida Tomás, Beatriz Santamaría, Clara Benedí-García, Ana I. Gómez-Varela, Verónica González-Fernández, Martina Delgado-Pinar. “The future researchers in Optics and Photonics: gender bias in the PhD theses defended in Spain in 2015-2020“, S2 Women in Physics – Oral contribution. (Abstract).

In addition, Carlos Hernández García participated in the organization of the congress as part of the scientific committee.

25 July, 2022 admin ALF results, Awards and honours, Events and congress, Scientific outreach No comments

RNO2021 – Ana García Cabrera awarded with one of the awards of this edition

The XIII National Meeting of Optics (#RNO2021) ended last week after three days full of interesting contributions and work.

It is with great regret that we say goodbye to this edition, although we do so with a bittersweet feeling since Ana García Cabrera, doctoral student and member of the GIR Aplicaciones Lásica y Fótonica was chosen as the winner of the RNO2021 award in the category of Quantum and Nonlinear Optics.

Ana presented her work “Ultrafast Talbot Spectroscopy” of which she is co-author along with Carlos Hernández – García and Luis Plaja. You can read the summary below.

Abstract:

High-order harmonic generation is an extraordinary tool that allows for the production of high-frequency coherent radiation in the form of very short pulses that can be used to unveil the properties of matter at the nanoscale. High-order harmonic generation occurs during the interaction of an intense laser with the atoms in matter. First, the laser distorts the atomic potential, releasing the electron through tunnel ionization. Then, the electron is accelerated by the laser field and redirected to rescatter with its parent ion, leading to the emission of radiation in the form of harmonics of the incident laser’s frequency. In the spatial scale where this process occurs, the electrons behave as waves and, therefore, they experience some phenomena that are typically observed in light, like the Talbot effect. The (optical) Talbot effect leads to the formation of a series of self-images of a periodic field distribution —like that in a diffraction grating— at regular distances.

In this work, we simulate an experiment of matter Talbot imaging with the ionized electronic wavefunction in a crystal during the high-order harmonic generation. The periodic wavefunction in the crystal is released by the laser field and, upon its evolution, it experiences the formation of Talbot self-images over time. The temporal modulations in the harmonic signal, caused by the matter Talbot effect, leave a trace in the harmonic spectrum that depends on the band occupation of the crystal. Therefore, we propose a new spectroscopic tool, ultrafast Talbot spectroscopy, based on the already known Talbot -Lau interferometry.

You can consult the article that she has published about this same work in the following link or download it from the institutional repository of the University of Salamanca GREDOS.

Ana García-Cabrera et al 2021 New J. Phys. 23 093011

We congratulate Ana and the rest of the congress winners and finalists!

All the details of the congress can be consulted on its website and its Twitter account (hashtag #RNO2021)

23 November, 2021 admin Awards and honours, Events and congress No comments

ALF-USAL Participation in RNO2021 – Poster Session

Several members of the Group of Applications Laser and Photonics (ALF – USAL) present the results of their research in the Poster Sessions organized during the XIII National Meeting of Optics (RNO 2021) that is taking place virtually from November 22 to 24 of 2021.

The works presented are included below:

All the details of the congress can be consulted on its website. You can also follow the event through the Twitter account of the XIII National Optics Meeting and the hashtag #RNO2021.

Structuring XUV Vector-Vortex Beams via High Harmonic Generation

Authors: Alba de las Heras, Alok Kumar Pandey, Julio San Román, Javier Serrano, Elsa Baynard, Guillaume Dovillaire, Moana Pittman, Charles G. Durfee, Luis Plaja, Sophie Kazamias, Olivier Guilbaud, y Carlos Hernández–García

Abstract: Structured light in the short-wavelength regime is emerging as a paramount tool to explore ultrafast spin and electronic dynamics. In this work, we demonstrate experimentally and theoretically the up-conversion of Vector-Vortex Beams (VVB) from the IR to the XUV regime, introducing a unique configuration of XUV coherent radiation spatially structured in its polarization and phase. The build-up of high-order harmonic generation driven by VVB is governed by the conservation of the Pancharatnam topological charge, which considers the intertwined spin and orbital angular momentum properties. The selection rule results in harmonic VVB with a high topological charge and smooth propagation dynamics.

A new post-compression scheme: nonlinear propagation in multipass cells.

Authors: Victor Segundo-Staels, Enrique Conejero Jarque y Julio San Roman1.

Abstract: The development of short, pulsed lasers has paved the way of new scientific disciplines such as the femtochemistry or the attoscience. There are several well-known schemes to generate extremely short pulses, such as the post-compression techniques. One of the most used post-compression methods consists of the spectral broadening of the pulse via its nonlinear propagation through a hollow-core capillary filled with a gas. The post-compressed pulse obtained, after passing a phase compensation stage, can reach the few- and even single-cycle regime.

We have developed a numerical model to study the nonlinear propagation of a laser pulse in an MPC. It is based on the standard Split-Step Fourier scheme in 4 dimensions, namely 3 cartesian coordinates plus the time dimension, as done by M. Hanna and co-workers7. As usual, the nonlinearities are processed in the space-time domain and linear effects in the frequency domain. Our code is written in MATLAB, employing some recent storage functions that allow us to work with big amounts of data. Normally we use a resolution grid of 128x128x512x𝑍 points, where 𝑍 is the propagation coordinate, which could be adjusted with adaptative steps based on the nonlinearity demands. With this precision we solve the propagation of tens of roundtrips in short amounts of time, which allows us to have bigger accuracy in transversal or temporal coordinates. Currently, we are able to retrieve previous results from the literature of spectral broadening in MPCs. This will allow us to study the behaviour of MPCs in different scenarios and to study the role of other nonlinear terms that could be relevant in some situations.

Generación de armónicos de orden elevado en presencia de campos magnéticos ultraintensos.

Authors: Rodrigo Martín, Luis Plaja y Carlos Hernández – García.

Abstract: El auge del estudio de haces de luz estructurados en los últimos años ha permitido demostrar nuevos esquemas en los procesos de interacción láser-materia. Un ejemplo son los haces de luz vectoriales con polarización azimutal, mostrando un campo magnético longitudinal oscilante a frecuencias ópticas. Estos campos magnéticos pueden llegar a ser del orden de giga-Tesla para intensidades máximas del haz vectorial en el rango de 10²¹ W/cm². En este trabajo se ha estudiado cómo estos campos magnéticos pueden afectar al proceso de generación de armónicos de orden elevado. Hemos observado cómo los espectros mejoran de manera notable tanto en eficiencia como en la frecuencia máxima que puede llegar a generarse. Además hemos dado una explicación desde un punto de vista fundamental de la dinámica que sufre el electrón durante su excursión por el continuo bajo el efecto del campo magnético. Por un lado, se produce una reestructuración de los niveles del continuo de manera análoga a un hilo cuántico, debido al confinamiento transversal del campo magnético. Por otro lado, la función de onda del electrón, tras la fotoionización, sufre de una dinámica de revivals o sucesivas focalizaciones que permite entender el aumento de las eficiencias y las frecuencias máximas que pueden obtenerse. Este trabajo presenta un nuevo esquema de la interacción láser-materia con la nueva generación de láseres de petavatio actualmente en construcción.

Pressures gradients in the compression of few-cycle pulses in gas filled hollow-core fibers.

Authors: Marina Fernández Galan, Julio San Román y Enrique Conejero Jarque.

Abstract: Gas-filled hollow-core fibers (HCFs) have been extensively used for generating intense ultrashort laser pulses, which are now essential tools in disciplines such as ultrafast spectroscopy or attosecond science. In this work, we have studied the generation of few-cycle pulses in HCF compressors with non-uniform pressure along the fiber. Varying the gas pressure, both dispersion and nonlinearity can be easily tuned, yielding output pulses with extremely short durations and a clean temporal profile.

Caracterización espacio temporal de vórtices ópticos ultracortos

Authors: Miguel López-Ripa, Íñigo Sola y Benjamín Alonso

Abstract: Las técnicas de caracterización espaciotemporal de pulsos ultracortos han ganado gran importancia a lo largo de las últimas décadas. En este trabajo hemos implementado un sistema de caracterización espaciotemporal compacto y ultraestable basado en interferometría por desplazamiento lateral en un montaje monolítico. Además, lo hemos empleado para caracterizar vórtices ópticos ultracortos generados usando láminas nanoestructuradas, demostrando su viabilidad y abriendo la puerta a explorar y optimizar nuevos casos de interés en aplicaciones de óptica ultrarrápida.

23 November, 2021 admin Attostructura_En, Events and congress No comments