A Method to Eliminating the Stress Delay from Fiber Grating Pressure Sensors
光纤光栅压力传感器中应力迟滞的消除方法

A method to eliminating the stress delay from fiber g rating pressure sensors by means of dual fiber grating is proposed.The tuning fo r Bragg wavelength disparity of the dual grating can be realized in the case of the effect of external pressure by a method that symmetrically adheres two FBGs with the same wavelength respectively to the upper and down surfaces of the cant ilever beam and links them up in series. The result of the research shows that t he technology can eliminate the stress delay of the fiber-grating pressure sens or caused by the elastic material of the devices, and improve the linear respons e characteristic and repeatability. Under the condition of the pressure range of 0~40 MPa, the tuning range of the system dual-peak wavelength disparity is 5.1 2 nm (two times of the range of single-peak wavelength tuning) and the sensitiv ity of dual-peak wavelength disparity in pressure tuning can reach the high deg ree of 0.128 nm / MPa (also two times of the single-peak one.