Ultrasonic induction system based on FBG (Fiber Bragg Grating), and sensor design

The invention relates to an ultrasonic induction system based on FBG (Fiber Bragg Grating), and a structure design of an optical grating detector. The overall structural characteristics of the ultrasonic induction system are that an adjustable laser source generates a narrow-band optical signal; the narrow-band optical signal enters into a designed FBG detector in a specific structure through a circulator, and, afterwards, transmission light and reflection light are collected; an electric signal generated through a photovoltaic conversion balance detector forms a linear relation with FBG wavelength drift amount; and then an ultrasonic signal is measured through the principles of FBG sensing. The structure design of the optical grating detector can circularly sense an ultrasonic signal transmitted by an object, and facilitates the subsequent processing and imaging of the ultrasonic signal. The system and design can effectively reduce the impact on ultrasonic detection from the power fluctuation of incident light. Compared with a conventional mode of piezoelectric ceramic ultrasonic induction, the system is high in sensitivity, and is convenient and quick for imaging.