A Novel High Sensitive Optical Fiber Microphone Based on a Singlemode-Multimode-Singlemode Structure

In this paper, a novel multimode interference based optical fiber microphone by employing singlemode-multimode-singlemode (SMS) structure is presented. The acoustic vibration is measured by detecting the transmission loss of the SMS structure that attached to a thick aluminum membrane. Experiments are carried on to test the performance of SMS structured fiber microphone and the experimental results show that the SMS fiber sensor can effectively detect the acoustic signal within the audio range of 20 KHz. It also exhibits a high sensitivity and human voice can also be picked up effectively within the distance of 2 m