Ultrasonic measurement device for realizing differential balance detection based on SAGNAC principle

Abstract

The invention discloses an ultrasonic measurement device for realizing differential balance detection based on an SAGNAC principle. The device comprises a light source, a first polarization controller, a second polarization controller, a first unpolarized 1*2 coupler, a second unpolarized 1*2 coupler, a sample probe, a circulator, a polarization beam splitter and a balance detector, light emittedby the light source firstly passes through et first polarization controller and the circulator and is divided into two paths with different lengths through the first unpolarized coupler, one path is CW light in the clockwise direction, and the other path is CCW light in the anticlockwise direction; modulation of pi / 2 initial phase and orthogonal polarization state of interference light is realizedand two beams of differential interference signals with equal intensity are formed by controlling the included angle between the two polarization controllers and the slow axis of the polarization beam splitter, and balance detection of the differential interference signals is realized by the balance detector. Compared with the prior art, the method for achieving non-contact ultrasonic detection through the SAGNAC effect has the advantages of being simple in structure, low in cost, small in size, high in sensitivity and wide in application range.

Description

technical field [0001] The invention belongs to the technical field of fiber optic gyroscopes, and in particular relates to an ultrasonic measuring device for realizing differential balance detection based on the SAGNAC principle. [0002] technical background [0003] When sound waves interact with matter, the speed of sound and the energy of sound waves will change. Through the measurement of sound speed and sound wave attenuation, some basic physical parameters of matter can be determined. This is ultrasonic testing technology, which is one of the basic methods to study the structure and properties of matter, and has been successfully applied in many fields. The traditional method of ultrasonic generation and reception is to use ultrasonic ring energy devices, such as piezoelectric transducers and CMUT transducers, and these methods are all contact measurement methods. At present, more and more traditional contact transducers are replaced by non-contact optical methods, i...

AI Technical Summary

Problems solved by technology

However, there are relatively few studies on the use of fiber optic sensors for ultrasonic testing, especially non-contact testing, especially domestic research

Images