Interferometers

In-fiber interferometers are a modern approach to optical fiber biosensors, as they allow the realization of sensors with high sensitivity based on in-fiber resonances or microstructured cavities. The modern approach condenses the interference between multiple light path, which generate resonant spectra, in a miniature optical fiber device with excellent sensitivity to the external analyte. In this chapter, classical interferometers (Fabry–Perot, Mach–Zehnder) as well as modern structures (such as spherical resonators, microcavity interferometers, and Sagnac loops) are presented with details on fabrication and performance.