We propose and demonstrate an optical fiber acoustic sensor based on air backing mandrel type fiber optic hydrophone. This novel approach to sensing sounds in the air has not been utilized before and has the advantage that the sensor doesn’t need electric power supply when it is working. To prove the feasibility of such an optical fiber acoustic sensor, we make a model and set up experiment to get the acoustic waves response curve in frequency. Because of its simple mechanical structure, the sensor is robust and shows a good application prospect.
