Conference Agenda

Although human vision is traditionally confined to the visible spectrum, recent research has revealed that pulsed near-infrared (NIR) light can be perceived as visible due to two-photon absorption (TPA) in the photoreceptors. This nonlinear optical process enables infrared photons to effectively stimulating the visual pigments in a manner similar to conventional visible-light absorption. This expands our understanding of retinal physiology and opens new possibilities for both fundamental and applied vision research. In this presentation, I will discuss our recent investigations into TPA-mediated vision, including its impact on visual acuity and color perception. Our experimental studies demonstrate that visual resolution under TPA conditions is comparable to that of normal visible-light vision, achieved by scanning a pulsed NIR beam across the retina to form letter stimuli. Furthermore, our psychophysical experiments reveal that perceived hues shift predictably with increasing NIR wavelength (880 to 1100 nm) and radiant power (10 to 30 µW), transitioning from reddish-purple to blue, green, and yellow-green. These findings provide novel insights into the intensity-dependent interplay between single-photon (1P) and two-photon (2P) absorption processes in human vision. Beyond its fundamental implications, TPA vision presents exciting clinical and technological opportunities. It offers a potential method for retinal diagnostics that circumvents ocular opacities. Additionally, the development of TPA-based RGB displays could revolutionize display technologies. This presentation will provide an overview of our key findings, the methodologies employed, and the broader impact of TPA vision research and applications.

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For the ninth time, the European Optical Society (EOS) is organizing a special session for EU project partners to disseminate their results. The session is organized in collaboration with Photonics21 and ICFO. During this session, projects will have the opportunity to present their goals and results to the conference audience.

INVITED SPEAKERS:

Roberta Ramponi, AEIT-CORIFI (IT)
Title: Photonics21 – Empowering European Photonics Innovation

Hugo Thienpont, Vrije Universiteit Brussel (BE)
Title: PhotonHub: Accelerating Photonics for Strategic Autonomy and Industrial Growth

Heidi Ottevaere, Vrije Universiteit Brussel (BE)
Title: PHORTIFY: PHOtonics education netwoRk for nexT-gen Innovation and digital skills excellence For industrY and society

Luis Trigo Vidarte, ICFO (ES)
Title: PIXEurope Pilto Line for Advanced Photonic Integrated Circuits

For decades, hollow core fibres have been a fascinating tool for scientists, enabling long distance light guidance in any gas, as well as innovative experiments exploiting the long light:gas interaction length. For a long time, their optical performance fell much shorter than the requirements of optical communications. Recently though, thanks to nested antiresonant designs, the loss of these fibres has reached lower values than fundamentally achievable in conventional glass-guiding telecoms fibres, opening exploitation opportunities in data-transmission systems. This, added to negligible nonlinearity, very high damage threshold and ultimately low latency, has dramatically increased global interest in the technology for numerous applications involving the transmission and delivery of light. While there are still substantial challenges to be solved before they can achieve widespread commercialization, it is hard to believe that hollow core fibres will not find an application in the optical communication networks of the future. In this talk we will review state-of-the-art, opportunities and challenges of the hollow core fibre technology.

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Join us for the official group photo of EOSAM 2025 in the Auditorium.

INVITED SPEAKERS:

Lydia Sanmartí-Vila
ICFO - 360 CARLA, Spain

Homa Zarebidaki
CSEM, Switzerland

Anne-Lise Viotti
Lund University, Sweden

Martin Caldarola
Single Quantum, The Netherlands

Read more: Industrial Optics Podium Session

• EOS Special Recognition Awards
• EOS Prize for the best paper published in the online, open access Journal of the EOS, JEOS-RP
• ICO-IUPAP Early Career Scientist Prize in Optics

Ultrafast laser-driven broadband Terahertz light sources are nowadays ubiquitous tools in many scientific fields, enabling researchers to control and probe an immense variety of low energy phenomena in condensed matter and other systems. They are also being increasingly deployed in industrial settings for inspection and non destructive testing: THz waves "see through" optically opaque objects, and can provide rich spectroscopic information at a glance. While techniques to generate short, broadband THz pulses using ultrafast laser pulses and nonlinear conversion techniques have seen continuous performance progress in the last few years, their average power has traditionally moved comparatively slowly, which has prevented many of these fields from blooming. On the other hand, the increasing availability and enormous performance progress of ultrafast Ytterbium-based lasers providing multi-100-W to kilowatt average-power levels has opened up the area of high average power, laser-driven THz sources: recent results reaching average power levels in the THz domain approaching the watt-level, opening the door to a multiplicity of new and old research areas to be re-visited. We review recent progress in the generation of high-average power THz-pulses, current technological challenges in scaling THz average power, and applications areas that could potentially benefit from these novel sources.

Device density in semiconductor chips continues to increase through many innovations. For example, high-NA EUV lithography enables the printing of smaller features that allow more devices in a smaller area. In addition, many innovations are taking place in the area of 3D device integration where devices are stacked on each other.
Manufacturing state-of-the-art chips with sufficient yield requires good control of many process steps during manufacturing. Overlay, for example, is a critical parameter in chip manufacturing. Overlay describes the lateral mis-alignment between 2 overlapping layers in a device. Any misalignment (=overlay error) can result in significant yield loss and overlay must therefore be controlled to the 1 nm level. These levels of control need accurate and robust overlay metrology.
Overlay is often measured on dedicated targets using optical microscopy. However, robustly achieving sub-nanometer precision requires near-perfect microscopic imaging conditions which drives the need for high-quality imaging optics with very low aberration levels. Technically this is possible, but it leads to complex and costly optical imaging systems. In order to keep metrology costs to acceptable levels there is a need for a microscopy approach that achieves the sub-nanometer precision levels in a more cost-efficient way.

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EOS celebrates distinguished members of the society with one of the highest categories of membership of the EOS: the Fellowship.

Optical frequency combs have revolutionized time and frequency metrology by providing rulers in frequency space that measure large optical frequency differences and/or straightforwardly link microwave and optical frequencies. Such combs enable precision laser spectroscopy, tests of fundamental physics and provide the long-missing clockwork mechanism for optical clocks.

While frequency combs have become key to research areas such as attosecond science, or calibration of astronomical spectrographs, one of the most successful applications beyond their original purpose has been dual-comb interferometry. An interferometer can be formed using two frequency combs of slightly different line spacing. Dual-comb interferometers without moving parts are fundamentally different from any other type of interferometers: they perform direct frequency measurements, without geometric limitations to resolution. They outperform state-of-the-art devices in an increasing number of fields including spectroscopy and three-dimensional imaging, offering unique features such as frequency measurements, accuracy, precision, speed. This talk will provide a short introduction to optical frequency combs and will survey dual-comb interferometry and its latest exciting developments.

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