Highly efficient iteration algorithm for a linear frequency-sweep distributed feedback laser in frequency-modulated continuous wave lidar applications

We present an iteration algorithm for generating the linear frequency sweep of a distributed feedback laser at 1550 nm both theoretically and experimentally. This iteration algorithm is convergent and can reach a desired frequency-sweep linearity with only a few iterations. Experimentally, the residual nonlinearity 1 - r 2 reaches 5.19 × 1 0 − 8 , and the relative frequency error is 0.005% with only six iterations, which has already been comparable to the linearity of the linear chirp signal generated by the external modulation method.