1-D acoustic cavity in optical fibers using two acoustic Bragg gratings

We report the fabrication and characterization of a one-dimensional acoustic cavity made on a tapered single-mode optical fiber with two acoustic mirrors. The mirrors are acoustic Bragg gratings formed by modulating the fiber diameter periodically. The cavity exhibits resonances with quality factors of around 300. Higher Q factors are achievable by increasing the number of periods in the gratings. A simple transfer matrix model successfully simulates the acoustic properties of the cavity. This type of acoustic cavity is of interest for its potential applications in acoustooptic components and the development of devices based on stimulated Brillouin scattering.