This grant provides funding for exploring the development of a novel fiber optic acoustic system for high-frequency bandwidth measurements. The novelty of the sensor system will be derived from the inclusion of extrinsic sensing capabilities based on a Fabry-Perot cavity, an integrated optical circuit based phase modulator, a high-speed photo detector, and a digital demodulation scheme based on a new multi-step phase stepping algorithm. The Fabry-Perot cavity will be located between the fiber tip and the diaphragm structure of the sensor, and the Mach-Zehnder interferometer in the phase modulator will be path matched with the Fabry-Perot arrangement to act as a read-out interferometer. Both experimental efforts and analytical efforts will be pursued for developing the sensor and understanding the sensor mechanics.
A potential risk involved in the development of this sensor system is that it may not be amenable to multiplexing as the other fiber-optic sensors. If successful, the development of this sensor system will have a tremendous impact on integrated active control systems for sound and vibration transmission problems where currently multiplexable sensors for high-frequency bandwidth applications are not readily available. Furthermore, if the sensor system is adapted, it can be used for high-frequency bandwidth pressure measurements in underwater flows. The sensor system may also have applications in the automotive industry such as ignition chambers
