Sagnac interference in integrated photonics

As a fundamental optical approach to interferometry, Sagnac interference has been widely used for reflection manipulation, precision measurements, and spectral engineering in systems. Compared other interferometry configurations, it offers attractive advantages by yielding reduced system complexity without the need phase control between different pathways, thus offering high degree of stability against external disturbance low wavelength dependence. The advance integration fabrication techniques enabled chip-scale interferometers with greatly footprint improved scalability compared more conventional approaches implemented spatial light or fiber devices. This facilitates variety integrated photonic devices bidirectional propagation, showing new features capabilities unidirectional-light-propagation such as Mach-Zehnder (MZIs) ring resonators (RRs). Here, we present our latest results functional based on interference. We outline theory comparisons building blocks MZIs, RRs, crystal cavities, Bragg gratings. realized chips, including mirrors, gyroscopes, basic filters, (de)interleavers, analogues quantum physics.