A calibration method for PZT phase shifter is developed
which is used in Spectral Domain OCT (SDOCT). Two steps are included in the calibration process: the first step is the rough calibration by the method of detecting and tracking the fringe patterns; the second step is fine calibration by a difference spectrum method with a precision increase of 6%. The experimental results in real differential SDOCT system show that a signal-to-noise ratio (SNR) increase of 10% is acquired by the method mentioned above.