[INVITED] Silicon nitride photonic integration for visible light applications

In this article, we provide a review of fabrication platforms and state of the art developments in the area of silicon nitride photonic integrated circuits (PICs) for the visible wavelength range, mostly employed in biomedical and chemical sensing applications. Additionally, we introduce PIX4life, the European pilot line for silicon nitride PICs for visible applications. PIX4life provides a unified framework for the development of such PICs, including design and software, fabrication, characterization and packaging.