In order to improve the demodulating speed and precision of the instrument

this paper propose a double-edge demodulation and nonlinear correction method to modifythe hysteresis effectof the piezoelectric ceramic.The demodulating speed and accuracy of the instrument has been improved by a cross-demodulation method using the data at rising edge and failing edge of triangle voltage at the same time.The effectiveness of thenonlinear correction method has been verified using a C band grating with 10 detection points.It is found that the wavelength demodulation error is less than ±5pm.