A self-compensating fiber interferometric displacement measurement system which is made with a fiber 3×3 coupler and fiber Bragg gratings(FBGs) is presented.The measurement system includes two fiber Michelson interferometers.One is used to stabilise the system by using an electronic feedback loop to compensate the environmental disturbances,while the other one is used to perform the measurement task.By means of phase-tracking homodyne technique,the linear regression coefficient of the measuremen...