A high-precision range extraction method using an FM nonlinear kernel function for DFB-array-based FMCW lidar

Frequency modulated continuous wave (FMCW) lidar is a high-precision absolute distance measurement technology in which the resolution is proportionate to the frequency modulation (FM) bandwidth of the light source. The distributed feedback (DFB) array exhibits advantages that meet FMCW lidar, such as a wide FM range, narrow linewidth, high FM speed, and low cost. However, the existing range extraction method for DFB array-based FMCW lidar has problems such as signal splicing error, residual FM nonlinearity, high sample rate requirement, and dispersion mismatch. Here, we propose and demonstrate an FM nonlinear kernel function based range extraction method, which improves the measurement precision of DFB array-based FMCW lidar. The distance to a target located at 5 m is experimentally measured using this method, and a precision of 1.9 mu m is obtained, which is much better than the existing range extraction method under the same conditions.