Laser frequency sweep linearization by iterative learning pre-distortion for FMCW LiDAR

• Published in: Optics express Vol. 27; no. 7; pp. 9965 - 9974
• Main Authors: Zhang, Xiaosheng, Pouls, Jazz, Wu, Ming C
• Format: Journal Article
• Language: English
• Published: United States 01.04.2019
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/oe.27.009965

We report on a laser frequency sweep linearization method by iterative learning pre-distortion for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR) systems. A pre-distorted laser drive voltage waveform that results in a linear frequency sweep is obtained by an iterative learning controller, and then applied to the FMCW LiDAR system. We have also derived a fundamental figure of merit for the maximum residual nonlinearity needed to achieve the transform-limited range resolution. This method is experimentally tested using a commercial vertical cavity surface-emitting laser (VCSEL) and a distributed feedback (DFB) laser, achieving less than 0.005% relative residual nonlinearity of frequency sweep. With the proposed method, high-performance FMCW LiDAR systems can be realized without expensive linear lasers, complex linearization setups, or heavy post-processing.