Abstract
The nonlinearity of a piezo-electrical transducer (PZT) driven tunable optical filter (TOF) is investigated and evaluated using FBG optical fibre sensing system including a broadband optical source and a tunable laser (TL) with a group of fiber Bragg gratings (FBGs). Polynomial fit is adopted to model the nonlinearity. Under three-order polynomial fit, the random error in wavelenght measurement using this TOF and a reference FBG is minimized to be below 20pm.