Lasers4EU

Laserlab-Europe Talk: Nonlinear optical diode effect in a magnetic Weyl semimetal, 26 Nov 2025
2025-11-26 16:00 - 17:00 (Europe/Berlin)
Speaker: Christian Tzschaschel (University of Zurich)
Weyl semimetals have emerged as a promising quantum material system to discover novel electrical and optical phenomena, due to their combination of nontrivial quantum geometry and strong symmetry breaking. Here, I will present the observation of the nonlinear optical diode effect (NODE) in the magnetic Weyl semimetal CeAlSi, where the magnetic state of CeAlSi introduces a pronounced directionality in the nonlinear optical second-harmonic generation (SHG). By physically reversing the beam path, we show that the measured SHG intensity can change by at least a factor of six between forward and backward propagation over a wide bandwidth exceeding 250 meV. Supported by density-functional theory calculations, we establish the linearly dispersive bands emerging from Weyl nodes as the origin of the extreme bandwidth. By utilizing the electronically conductive semimetallic nature of CeAlSi, we demonstrate current-induced magnetization switching and thus electrical control of the NODE in a mesoscopic spintronic device structure. Our results advance ongoing research to identify novel nonlinear optical/transport phenomena in magnetic topological materials. The NODE further opens new pathways for the unidirectional manipulation of light such as electrically controlled optical isolators [1].
[1] CT et al., Nature Communications 15, 3017 (2024)

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Laserlab-Europe Talk: Non-invasive photoacoustic imaging for in-depth cultural heritage diagnostics, 10 Dec 2025
2025-12-10 16:00 - 17:00
Speakers: Eleanna Pirgianaki (IESL-FORTH)
In recent years, photoacoustic (PA) techniques have gained significant role in the field of cultural heritage (CH) diagnostics, proving to be powerful tools for the detailed investigation of complex and fragile objects such as paintings, documents and murals. These techniques are based on the PA effect, which involves the generation of acoustic waves as a result of the absorption of intensity-variable optical radiation. The excitation and detection of PA signals through spectroscopic or imaging modalities is non-invasive and non-destructive and provides high optical absorption sensitivity at substantial depths within opaque media, surpassing the performance of several purely optical diagnostic methods.
In this context, we present a novel reflection-mode PA system integrating near-infrared pulsed excitation light and a spherically focused air-coupled ultrasonic transducer for the detection of the generated PA waves. The system is specifically developed to detect in-depth ageing effects in painted mock-ups and to reveal hidden underdrawings, such as pencil sketches, beneath non-transparent paint layers. To assess the performance of the system in detecting degradation phenomena, PA responses were recorded from different pigmented layers that had undergone controlled thermal or photo-ageing treatments. The measurements revealed a progressive increase in the PA amplitude over time, with distinct deterioration rates observed for various types of paint.
Additionally, by employing a second-harmonic excitation wavelength at 532 nm and comparing the PA signal ratios obtained from the two excitation lines, we aimed to enhance the method’s detection sensitivity while also expanding its applicability. Beyond the investigation of ageing effects in painted mock-ups, the developed dual-wavelength PA approach enabled the identification of corrosion levels in various metals and alloys, differentiation among inks of similar visual appearance, and detection of degradation effects in artificially aged papers. Overall, these results highlight the strong potential of PA detection as a complementary diagnostic technique to traditional methods, offering highly sensitive and non-destructive insights into degradation mechanisms and subsurface features across a broad range of CH artifacts.

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Lasers4EU Activity Board meeting, 13 January 2026
2026-01-13 10:30 - 12:00
The Activity Board of the Lasers4EU project will hold its next meeting on 13 January from 10:30 to 12:00 CET.
Login details will be provided by the Laserlab-Europe Office.
Please note: this is an internal project event.

Laserlab-Europe Talk: Laser produced plasmas (LPP) and LPP SXR/EUV sources for laboratory astrochemistry, 28 January 2026
2026-01-28 16:00 - 17:00
Speaker: Andrzej Bartnik (MUT-IOE) Date: Wednesday, 28 January 2026, 16:00 CET
Many experiments relevant to various processes in Space were devoted to support interpretation of astronomic observations. The experiments concern formation of astrophysical jets, photoionized plasmas in accretion disks around compact stars, supernovae explosions, matter formed inside giant planets, formation of interstellar dust, molecular processes in interstellar ices, formation of tholins etc. It is so called laboratory astrophysics or astrochemistry.
Some of these experiments require using of high power discharge or laser systems, for some experiments, especially concerning laboratory astrochemistry, synchrotrons, VUV lamps or small scale discharge plasma systems were employed. Some experiments can be, however, performed using laser produced plasma (LPP) soft X-ray (SXR) or extreme ultraviolet (EUV) sources. Some attempts were performed using sources developed in Institute of Optoelectronics, MUT.
The sources utilize gas puff targets and nanosecond, Nd:YAG laser systems. The most intense emission in the SXR or EUV range can be obtained from Xe plasmas, however, in some cases other gases or aerosols are employed. The sources are equipped with the corresponding EUV/SXR optical systems. Some experiments are performed in an ambient gas, under low pressure. Both kind of systems, with and without optics, can be employed for investigation of molecular processes relevant to SXR/EUV induced processes in interstellar clouds, atmospheres of planets or comets. Initial experiments were performed, a series of further experiments is planned.

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Laserlab-Europe Talk: Laser processing of functional micro/nanostructures for photonics, optoelectronics, and smart surfaces, 25 Feb 2026
2026-02-25 16:00 - 17:00
Speaker: Maria Kandyla (National Hellenic Research Foundation)
The need for advanced materials and systems with new functionalities has motivated the development of micro/nanostructures on solid surfaces, which are necessary for the fabrication of functional devices for novel applications. In this talk, we will discuss the development of functional micro/nanostructures, based on laser-processed surfaces.
Coating micro/nanostructures with thin metallic films results in plasmonic substrates with enhanced electromagnetic response across the entire visible range, which are used for plasmonic optical trapping [1]. Combining silicon micro/nanostructures with thin semiconducting films results in electronic heterojunctions with increased surface area for improved optoelectronic performance [2]. Furthermore, isotype heterojunctions result in wavelength-selective, high-speed photodetectors with self-powered operation, which can be further engineered by careful selection of the electronic properties of the constituting materials [3,4]. “Smart” surfaces of controllable extreme wetting states are obtained by combining photoresponsive metal oxides with laser-processed micro/nanostructured substrates, which can reach complete water repellence without chemical modification [5]. Also, surfaces with controlled topography, either at the micro- or at the nano-scale, for targeted cell cultures for biomedical applications [6]. We will present recent advances in these fields and discuss future applications.
References

D.G. Kotsifaki, M. Kandyla, and P.G. Lagoudakis, Plasmon enhanced optical tweezers with gold-coated black silicon, Scientific Reports 6, 26275 (2016).
G. Chatzigiannakis, A. Jaros, R. Leturcq, J. Jungclaus, T. Voss, S. Gardelis, and M. Kandyla, Laser-microstructured ZnO/p-Si photodetector with enhanced and broadband responsivity across the ultraviolet-visible-near-infrared range, ACS Applied Electronic Materials 2, 2819 (2020).
G. Chatzigiannakis, A. Jaros, R. Leturcq, J. Jungclaus, T. Voss, S. Gardelis, and M. Kandyla, Broadband wavelength-selective isotype heterojunction n+-ZnO/n-Si photodetector with variable polarity, Journal of Alloys and Compounds 903, 163836 (2022).
M.D. Tsanakas, A. Jaros, Y. Fleming, M. Efthimiadou, T. Voss, R. Leturcq, S. Gardelis, and M. Kandyla, Wavelength-selective, high-speed, self-powered isotype heterojunction n+-ZnO/n-Si photodetector with engineered and tunable spectral response, Advanced Materials Technologies 10, 2401740 (2025).
M. Kanidi, A. Bardakas, A. Kerasidou, A. Anastasopoulos, C. Tsamis, and M. Kandyla, Hierarchical ‘rose-petal’ ZnO/Si surfaces with reversible wettability reaching complete water repellence without chemical modification, Applied Physics A 129, 320 (2023).

M. Kanidi, A. Papadimitropoulou, C. Charalampous, Z. Chakim, G. Tsekenis, A. Sinani, C. Riziotis, and M. Kandyla, Regulating MDA-MB-231 breast cancer cell adhesion on laser-patterned surfaces with micro- and nanotopography, Biointerphases 17, 021002 (2022).

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Lasers4EU Activity Board meeting, 2 April 2026
2026-04-02 10:00 - 12:00
The Activity Board of the Lasers4EU project will hold its next meeting on 2 April from 10:00 to 12:00 CEST.
Login details will be provided by the Laserlab-Europe Office.
Please note: this is an internal project event.

Laserlab-Europe Talk: Materials and post-processes for multi-photon lithography, 29 April 2026
2026-04-29 16:00 - 17:00
Title: Materials and post-processes for multi-photon lithography
Speaker: Dimitra Ladika (VULRC)
Date: Wednesday, 29 April 2026, 16:00-17:00 Central European Summer Time (CEST)
Multi-photon lithography (MPL) enables the fabrication of true 3D micro- and nanostructures without the need for masks or complex tooling, directly from computer-aided designs. Owing to these unique capabilities, MPL has emerged as a powerful manufacturing technique across a wide range of disciplines. The ongoing growth of MPL is closely linked to advances in material design and post-processing strategies.
In particular, the composition of MPL photoresists, including the presence or absence of photoinitiators, plays a critical role in defining fabrication thresholds, resolution, and the optical properties of the resulting structures. While photoinitiators can enhance polymerization efficiency, they may also introduce fluorescence and coloration, limiting their use in certain applications. In contrast, photoinitiator-free and doped systems offer alternative pathways toward improved optical performance. The interaction of these materials with femtosecond laser irradiation across multiple wavelengths provides additional flexibility for controlling polymerization and tailoring spectral response.
Additionally, post-processing approaches, such as calcination and surface coatings, further extend the capabilities of MPL by enabling the fabrication of fully inorganic and spectrally adaptable architectures. These strategies enhance the functionality and stability of the fabricated 3D structures without fundamentally altering the initial material platform.
Overall, these developments demonstrate the potential of material-driven approaches in MPL for applications in photonics and optoelectronics.
Registration here

Lasers4EU Access Board meeting, 5 May 2026
2026-05-05 14:30 - 16:30
The Access Board of the Lasers4EU project will meet on 5 May 2026, 14:30-16:30 CEST.
The link to connect will be shared by the Laserlab-Europe office.

This is a project internal event.

Laserlab-Europe Talk: Elucidating the Photon Migration Effects in Incubated Chicken Eggs using Time-Domain Diffuse Optics, 20 May 2026
2026-05-20 16:00 - 17:00
Title: Elucidating the Photon Migration Effects in Incubated Chicken Eggs using Time-Domain Diffuse Optics Speaker: Lennard van den Tweel (Wageningen University and Research) Date: Wednesday, 20 May 2026, 16:00 Central European Summer Time (CEST)
The early and non-invasive assessment of chicken embryonic sex and viability is of great interest. This interest is driven by the ethical dilemma surrounding the culling of non-productive day-old male chicks in layer-hen production and by the need to improve hatchery efficiency. Optical techniques are widely investigated for these applications, but are challenged by the complex optical properties and heterogeneous structure of avian eggs. Here, we show that chicken eggs display unusual photon trapping behavior due to the eggshell behaving like an integrating sphere, considerably extending photon time-of-flight. Time-domain diffuse optical spectroscopy (TD-DOS) on egg phantoms, supported by Monte Carlo simulations and post-dispersive filtering experiments, rule out fluorescence as the source for the long photon time-of-flight. These results point to diffuse reflections at the inner surface of the eggshell as the source of the long photon time-of-flight. Despite these boundary effects, the retrieval of internal bulk optical properties remains feasible via inversion of the diffusion approximation after selection of appropriate boundary conditions, as was demonstrated in incubated eggs. Finally, phantom experiments illustrate how the integrating sphere affects the temporal response of time-resolved Raman and fluorescence measurements, highlighting critical challenges in non-invasive optical characterization of avian embryos.

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Laserlab-Europe and Lasers4EU Annual and Users Meeting 2026, 26-29 May 2026
2026-05-26 - 2026-05-29 | HiLASE, Dolni Břežany, Czech Republic

Lasers4EU Training | Experimental methods and data analysis for femtosecond and attosecond spectroscopies: transient absorption spectroscopy, time-resolved photoelectron/photoion spectroscopy, 9-11 June 2026
2026-06-09 - 2026-06-11 | Max-Born-Institute, Berlin, Germany

Lasers4EU Training | Hands-on Course on MINDLAB: Manipulating and Investigating Neural Dynamics for Learning and Ageing in the Brain, 13-17 July 2026
2026-07-13 - 2026-07-17 | Castelldefels, Castelldefels, Barcelona, Spain
The core faculty of the ICFO-MINDLAB, a think tank working jointly towards a transdisciplinary understanding of the brain, offers a school to introduce cutting edge technologies to study neuroscience at the molecular, cellular and systems level to students in a combination of lectures and hands-on experience leading to group projects.
What is MINDLAB?
MINDLAB stands for “Manipulating and Investigating Neural Dynamics for Learning and Ageing in the Brain” and is an interdisciplinary creative playground rooted squarely in academic rigor, comprising of research groups from ICFO and beyond. We focus on advancing fundamental knowledge on how the mind emerges from the behavior of individual molecules, neurons and brain networks but also creating and commercializing transformational future technologies with outstanding potential to impact our society for good.
Hence, this course will expose participants to the state-of-the-art of photonics-based technologies tailored to monitor a hierarchy of scales in the study of the brain: i.e. from single molecules up to the whole organism.
The MINDLAB faculty includes world leading experts in their fields. The expertise of the core faculty is complemented by a diverse set of affiliated adjunct faculty from various research centres in Barcelona but also through clinical and corporate partners.
This year’s school coincide with the arrival of ICFO’s Summer Fellows, a group of highly motivated master-level or engineering students in their final years of study, who join ICFO research groups for three-month internships (July-September)
Hands-on sessions
Participants will engage in lab sessions focused on the latest photonics technologies. Each lab session will provide participants with an opportunity to work directly with advanced equipment and gain valuable practical skills.
The sessions will take place in the following labs:

Super resolution Light microscopy and Nanoscopy
Neurophotonics and Mechanical Systems Biology
Medical Optics
Photon Harvesting in Plants and Biomolecules
Single Molecules Biophotonics
