Microring resonator arrays for sensing applications

Integrated optical circuits, including microring resonator elements (MRR), provide a sensitive, specific, and reliable technology platform for the development of compact and smart microsystems for sensing applications, for example, chemical and label-free biochemical analysis as ultra-small MRRs feature extraordinary sensitivity to changes of environmental parameters. Some basic features of MRRs and figure of merits for an appropriate design are given as well as an overview on the most relevant material systems and technologies for the prospective fabrication of MRR devices in high-volume production on wafer level. Application-relevant approaches for an implementation of MRR based on-chip multiparameter analytics by using optical multiplexing techniques are summarized, first experimental results are given, and some architectures of optical circuit approaches for an efficient implementation of MRR-based sensor arrays in entire sensor systems are sketched. Finally, some perspectives extrapolate how well-engineered circuit integration will enable the development of smart, practical, portable, or handheld microsystems.