The outstanding development of photonic technologies that has occurred in recent decades has allowed their implementation with great success in a wide variety of areas such as high-speed communications, sensors, high-precision medicine tools, scientific instrumentation, space technologies, etc. Driven by this trend, the Global Photonics Market was valued at USD 722.31 billion in 2021, and it is expected to reach USD 1089.00 billion by 2027[1]. However, to push forward photonic technologies, two fundamental aspects need to be addressed.
On the one hand, to create manufacturing processes for the fabrication at sub-micrometric scales that are cost-efficient and provide reproducible results at industrial level to evolve photonic and nanophotonic technologies in the same way that the integrated circuit evolved electronics in the second half of the 20th century.
On the other hand, the design and functional demonstration of a family of versatile and robust photonic devices able to work under harsh environmental conditions to address the requirements of the most demanding applications.
Funded by the Marie Skłodowska-Curie Actions programme, the GRAIL Project focused on the study, application and improvement of a novel 3D nanolithography fabrication technique for the development of fully monolithic and crystalline photonic elements (e.g. waveguides, diffraction gratings, etc) and devices (e.g. full laser cavity), emphasizing on miniaturization, reproducibility and capabilities to bring the technique to high levels of integration and mass production.
The GRAIL project successfully demonstrated the feasibility of utilizing the 3DLW technique in combination with giant wet-etching selectivity to fabricate photonic components relying on pronounced refractive index steps. Additionally, the project explored the use of 3DLW for controlled small refractive index modulations, uncovering evidence of both positive and negative changes. This breakthrough significantly broadens the possibilities for producing advanced 3D microphotonic devices in both crystalline and non-crystalline materials.
Moreover, the strong collaboration with industrial partners during the project facilitated the demonstration of nanoscale and optical-grade structures produced using current state-of-the-art industrial equipment with minimal adaptations. These achievements not only validate the industrial viability of the techniques but also pave the way for future advancements in photonic device manufacturing.
[1] PHOTONICS MARKET - GROWTH, TRENDS, COVID-19 IMPACT, AND FORECASTS (2022 - 2027), Mordor Intelligence Inc.
