SOFT MATTER PLATFORM FOR OPTICAL DEVICES VIA ENGINEERING OF NON-LINEAR TOPOLOGICAL STATES OF LIGHT

Project Information

TopoLight

Grant agreement ID: 964770

DOI

10.3030/964770

Project closed

EC signature date 22 January 2021

Start date 1 September 2021

End date 31 May 2025

Funded under

• EXCELLENT SCIENCE - Future and Emerging Technologies (FET)

Total cost

€ 3 099 353,75

EU contribution

€ 3 099 353,75

Coordinated by

UNIWERSYTET WARSZAWSKI
Poland

Periodic Reporting for period 3 - TopoLight (SOFT MATTER PLATFORM FOR OPTICAL DEVICES VIA ENGINEERING OF NON-LINEAR TOPOLOGICAL STATES OF LIGHT)

Reporting period: 2023-09-01 to 2025-05-31

Summary of the context and overall objectives of the project

TopoLight explored a new paradigm for controlling light by integrating anisotropic liquid crystals into polaritonic microcavities, enabling external electrical control over spin–orbit interactions and topological photonic states at room temperature. The project demonstrated that liquid-crystal-based platforms offer a technologically accessible route to tunable photonic devices, relying on comparatively simple fabrication approaches such as spin-coating or sputtering of organic emitters and filling cavities with liquid crystals, while avoiding the need for complex solid-state processing.

A major achievement of the consortium was the experimental realization of tunable polaritonic microlasers exhibiting engineered spin textures. TopoLight researchers reported a novel microlaser emitting two circularly polarized beams propagating at distinct angles, enabled by the formation of a persistent spin helix within a liquid-crystal-filled microcavity. This effect resulted from precise molecular alignment that produced polarization-dependent cavity modes whose resonance could be smoothly tuned with an external electric field. When the modes overlapped, the emission transitioned from linear to counter-propagating circular polarizations, revealing electrically controllable chiral light generation.

Phase coherence between the modes was confirmed through the observation of a persistent spin-helix interference pattern, consistent with theoretical predictions and linked to the inseparability of the optical states. These results establish a robust platform for manipulating polarization and topology in photonic systems.

TopoLight also advanced the broader goal of tunable photonic structures, opening pathways toward practical chiral lasers for enhanced information encoding and versatile spatial light modulators operating across polarization and spectral domains. Beyond laser technologies, the project demonstrated the potential of nonlinear polaritonic systems for fully optical neuromorphic architectures capable of high-speed, energy-efficient information processing.

While the current devices operate in pulsed regimes due to photodegradation of organic dyes, the project identified clear routes toward longer operational lifetimes through the adoption of more durable emitters such as polymers and inorganic materials, including perovskites.

Conclusions of the action: TopoLight has established an electrically controllable platform for polarization- and topology-engineered light sources operating at room temperature. By combining liquid-crystal tunability with polaritonic physics, the project delivered fundamental advances in spin–orbit photonics, demonstrated new device concepts such as electrically tunable chiral microlasers, and created opportunities for applications spanning communication technologies, sensing, machine learning hardware, and advanced optical modulation. These achievements position the technology for further development toward practical and adaptable photonic systems.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During the TopoLight project, significant progress was made in the design, fabrication, and control of liquid crystal-based photonic devices. Key scientific and technological achievements include:
• Development of organic/liquid crystal (O/LC) microcavity technology enabling tunable and controllable light-matter interactions.
• Fabrication of a tunable liquid crystal laser prototype demonstrating versatile control of emission properties.
• Exploitation of self-organization in optical cavities to engineer tailored photonic potentials.
• Implementation of photoalignment techniques to further control photonic potential landscapes.
• Discovery of a new quantum material – a supersolid condensate.
• Demonstration of spin-orbit coupling of light, optical persistent spin helix, Stern-Gerlach experiments, chiral lasing, and electrical control over topological exceptional points of light.

Throughout the project, TopoLight results were widely disseminated across scientific and public domains:
• Scientific publications: over 30 peer-reviewed papers in high-impact journals including Nature Communications, Physical Review Letters, Physical Review Research, Physical Review B, Journal of Applied Physics, Science Advances, and Journal of the American Chemical Society, all provided with open access to publications and associated data.
• Conferences and outreach: Results were presented at multiple prestigious international conferences. Public engagement activities were conducted in schools and community centers, increasing the visibility and recognition of TopoLight.
• Monitoring and impact assessment: Each partner tracked dissemination activities via network worksheets, enabling evaluation of the effectiveness and sustainability of exploitation efforts in line with the project’s Key Performance Indicators (KPIs).

Overall, the project successfully combined groundbreaking scientific discoveries with robust dissemination, ensuring both scientific impact and public engagement.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The TopoLight project has advanced the frontiers of photonics and quantum materials, laying the groundwork for future applications in secure communication, tunable lasers, and quantum information technologies. By enabling controllable vectorial light fields and versatile photonic devices, the project demonstrates potential for technological exploitation in both research and industry, even though direct socio-economic impacts are still emerging.

Beyond its scientific outcomes, TopoLight has had a significant impact on career development and training. The project supported the careers of 11 BSc, Eng and MSc students, 4 PhD students, and 5 postdoctoral researchers, who actively participated in regular interdisciplinary meetings and collaborative research activities across all partner institutions. These activities fostered international collaboration, skill development, and exposure to cutting-edge research in topological photonics and quantum materials, helping to train the next generation of European researchers.

Through its structured collaboration, transparent decision-making, and use of cloud-based platforms for communication and co-authorship, TopoLight has also established a sustainable model for effective research management and international scientific teamwork.

Tunable microlaser emitting two circularly polarized beams (illustration)

TopoLight logo