Revolutionary Accuracy in waVeguide- and photoacoustic-ENabled atmospheric sensors (RAVEN)

Project Information

RAVEN

Grant agreement ID: 101135787

DOI

10.3030/101135787

EC signature date 30 May 2024

Start date 1 June 2024

End date 31 May 2028

Funded under

• Digital, Industry and Space

Total cost

€ 4 813 147,50

EU contribution

€ 4 813 147,50

Coordinated by

ITA-SUOMEN YLIOPISTO
Finland

Periodic Reporting for period 1 - RAVEN (Revolutionary Accuracy in waVeguide- and photoacoustic-ENabled atmospheric sensors (RAVEN))

Reporting period: 2024-06-01 to 2025-05-31

Summary of the context and overall objectives of the project

Clean air and a stable climate are fundamental to human health, environmental protection, and sustainable development. Yet, anthropogenic emissions of air pollutants and greenhouse gases (GHGs) continue to threaten both. In the European Union, air pollution remains the single largest environmental health risk, with pollutants like nitrogen dioxide (NO2), ozone (O₃), and ammonia (NH₃) regularly exceeding safe levels—especially in urban areas. Meanwhile, climate change demands urgent and precise tracking of GHGs such as carbon dioxide (CO2), methane (CH₄), and nitrous oxide (N2O). Responding to these challenges, the European Green Deal and the revised EU air quality standards call for more accurate, granular, and widespread environmental monitoring than current technologies can deliver.

The RAVEN project addresses this urgent need by developing next-generation gas sensing systems that are compact, low-cost, energy-efficient, and capable of high-precision detection across a broad range of pollutants and GHGs. Leveraging advanced photonic integrated circuit (PIC) technology, RAVEN will deliver two miniaturised sensor systems—one operating in the VIS-SWIR and the other in the MIR spectral range. Together, they will enable simultaneous, real-time and continuous monitoring of multiple gases with detection limits down to the parts-per-billion level. This breakthrough performance, coupled with portability and low energy requirements, will make it possible to deploy RAVEN sensors in remote, underserved, or mobile settings—providing data that is critical for air quality management, climate mitigation, and public health protection.

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

WP1: Preliminary dual-wavelength microchip laser sources for supercontinuum (SC) generation at 532 nm and 1064 nm were successfully developed, meeting initial design parameters. The LiNbO₃ waveguide for SC generation was designed and fabricated, with integration work underway. Experiments on coupling the laser source with the waveguide for SC generation have started, and initial results are guiding the next iteration of the waveguide design.

WP2: Ion-exchanged waveguides and Bloch Surface Wave (BSW) structures for the sensing chip were designed, with a successful first implementation of a 1-meter-long spiral waveguide on glass. Interfacing architectures between the BSW structures and the waveguides were finalised, and fabrication processes were established. Activities remain on schedule, with the next phase focusing on BSW sensor head fabrication and spiral design optimisation.

WP3: Hybrid polymer/TiO2 waveguides with low propagation loss (<1 dB/cm) were successfully demonstrated. Mach-Zehnder interferometers based on novel splitter concepts were designed, fabricated, and experimentally validated. These developments support on-chip data processing and will enable the implementation of multivariate and quantum-inspired algorithms for enhanced gas detection performance.

WP4: Development of the mid-IR (MIR) photoacoustic sensing (PAS) system advanced through fabrication of custom gain materials and chips for targeted wavelengths (2705 nm, 2888 nm, and 2359 nm). Initial PIC designs were completed, and fabrication is ongoing. A miniaturised photoacoustic cell has been modelled and is under mechanical design, with integration planned in the next phase. GASERA refined its modelling tool to optimise cell design parameters.

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 RAVEN project is progressing in line with the work plan, with all major technical activities initiated as scheduled and several foundational results already achieved. The first reporting period has focused primarily on designing and prototyping the critical photonic components required for the next-generation gas sensing systems, including preliminary laser sources, sensing chips, data processing platforms, and mid-infrared photoacoustic sensor elements. These early developments provide a solid technical basis for further system integration and performance validation in the coming phases.

While the results generated so far are still at an early stage, they support the feasibility of RAVEN’s core approach—namely, that miniaturised, low-power photonic sensors can offer high precision in detecting multiple air pollutants and greenhouse gases. However, the consortium recognises that many of these results are still preliminary and that further refinement and integration work is required before the full sensing systems can be validated in realistic environmental conditions. This is fully in line with expectations for this phase of the project, and the work completed during RP1 positions the consortium well to demonstrate and evaluate the system’s performance during RP2.

Based on the progress made so far, the RAVEN project remains well-placed to deliver on its intended impacts. There is no indication at this stage that the technological concept will fall short of its objectives. Looking ahead, the consortium has identified several key needs to ensure successful uptake: continued effort in system-level integration and the validation in three end-user applications, early alignment with regulatory and standardisation frameworks, and planning for commercialisation pathways, including IPR strategy and end-user engagement. These activities will be critical in translating RAVEN’s promising technological advances into real-world impact across environmental monitoring, climate policy, and industrial emissions control.

RAVEN logo