To make photonic sensors as widespread as electronic ones, challenges in size, cost, and weight must be addressed. Wafer-level silicon photonics offers a breakthrough by enabling compact, low-cost photonic solutions. Among these, Photonic Integrated Circuits (PICs) stand out as a versatile platform for light manipulation. By guiding light through micron- and nanometre-scale waveguides, PICs can deliver advanced sensing capabilities that rival bulkier, more expensive systems.
Beyond their role in the green and digital transition, PICs are vital to Europe's push for technological sovereignty, aligning with the European Chips Act. Following semiconductor supply disruptions during the Covid-19 pandemic, the EU set a goal to double its market share to 20% by 2030. This includes scaling up silicon photonics research, a priority heightened by geopolitical shifts such as the war in Ukraine and tensions with China.
The COMPAS project aims to advance photonics–microelectronics integration by developing a novel, wafer-level multi-analyte PIC sensor platform (PSP) using a chiplet approach. Its goal is to create a compact, affordable, and highly sensitive PSP for monitoring air and water, integrating light sources, detectors, and electronic ICs for on-chip signal processing.
To achieve this, partners will combine their expertise across several technologies. Optically active coatings—tailored to specific analytes—will be applied atop waveguide interferometers, with microfluidics delivering samples. Analyte capture alters the coating’s refractive index, changing light intensity detected by photodetectors. These signals will be processed using innovative low-power analog electronics.
A baseline version will use a mix of custom and standard components with advanced packaging. A fully integrated variant will feature waveguide interferometers atop monolithically integrated photodiodes, with a custom single-mode laser diode flip-chip assembled onto the waveguide. To boost sensitivity, optical metasurfaces will be developed for enhanced light coupling.
The final PSP will be tested in three scenarios:
1. VOC detection for identifying pest-infected plants (with EU project PurPest)
2. Water quality monitoring, focusing on estrogen and PFAS
3. Air quality sensing, targeting NOx and O₃