Nonlinear correction in the frequency scanning interferometry system by a fiber resonator

The tuning nonlinearity of a laser is the main source that will deteriorate the spatial resolution in a frequency scanning interferometry (FSI) system. In the present study, a nonlinear error correction method based on a fiber resonator is proposed. Equal-spacing frequency sampling is achieved by resampling the raw signal at the position of the peaks of the fiber resonator signal. The effectiveness of the method is evaluated by checking the spectrum of a 2-m Michelson or Mach–Zehnder interferometer (MZI) and its residual nonlinearity in the FSI scheme. The distributed strain measurement is also performed, which further verified the usefulness of the method in the tuning nonlinearity of the laser in FSI system. •The nonlinear error correction method based on a fiber resonator is proposed.•Equal-spacing frequency sampling is achieved by resampling the raw signal at the position of the peaks of the fiber resonator signal.•The distributed strain measurement is performed with the help of the tuning nonlinearity through a fiber resonator.