Development of ion-exchanged waveguides with low-bend radii and crossing angles in commercial thin glass for co-packaged optical sensors in glass core substrate

In this paper, we present our latest progress in thermal ion-exchange technology, a technique employed for the creation of low-loss optical waveguides characterized by low bend radii and small crossing angles at wavelengths of 1550 nm. This milestone has been achieved in commercially available multi-purpose panel sized Schott D 263 T eco thin glass, and its effectiveness has been validated through both 3D Finite-Difference Time-Domain (FDTD) simulation and empirical measurement of a range of benchmarking layouts. These advancements pave the way for a novel measurement arrangement for the precise determination of the Verdet constant in optical waveguides, and, conversely, the measurement of an external magnetic field or electrical currents. This compact 2D layout can be seamlessly integrated into glass core substrate-based Printed Circuit Boards (PCBs), serving as a galvanically isolated optical current sensor for both Alternating Current (AC) and Direct Current (DC) in power electronics. This allows for the optical signal detection to take place at a considerable distance from the electrical guide. Such developments for glass core substrate PCB push the boundaries of power electronics, by enabling accurate, reliable, and robust measurements that are galvanically isolated from the electronic circuit. This opens up new possibilities in terms of safety, efficiency, and miniaturization.