Fiber-optic multilayer hydrophone for ultrasonic measurement

Abstract An ultrasonic hydrophone is presented that comprises a fiber tip coated with a dielectric multilayer system. Two different layer designs are investigated with respect to their suitability for sensing and their reflectance slope which determines the sensitivity. The more advantageous Fabry–Perot stack was experimentally implemented, and first successful measurements are described. Low-intensity signals are detected with a high signal-to-noise ratio. The sensor can be used for acoustic pressure measurement with high temporal and spatial resolution in a wide power range.