A Submerged Optical Fiber Ultrasonic Sensor Using Matched Fiber Bragg Gratings

作者：Bai, Xiaohong; Hu, Manli^*; Gang, Tingting; Rong, Qiangzhou^*

来源：Sensors (Switzerland), 2018, 18(6): 1942.

DOI：10.3390/s18061942

• fiber optic ultrasonic sensor
• matched fiber Bragg grating
• sinusoidal ultrasound

A novel kind of fiber optic ultrasonic sensor based on matching fiber Bragg gratings (FBGs) is proposed and demonstrated. The sensors consist of a pair of matching FBGs fixed to a special bracket. The bracket plays a role in stretching and squeezing the FBGs, with the push-pull effect efficiently coupling the ultrasonic signal to the sensor, thus, improving the sensor's sensitivity. Side-band filtering technology-based intensity interrogation was used to detect ultrasounds in water. With the synergic effect of the matching FBGs, the sensor performed with a high signal-to-noise ratio (56.9 dB at 300 KHz, 53 dB at 1 MHz and 31.8 dB at 5 MHz) and the observed ultrasonic sinusoidal signals were undistorted and distinguishable in the time domain.

• 出版日期2018-6
• 单位西北大学