Adaptive digital Electro-Optical Phase-Locked Loop for frequency modulation linearization of FMCW LiDAR system
Year: 2025
Type: article
Abstract: We demonstrate a closed-loop Electro-Optical Phase-Locked Loop (EO-PLL) designed to increase the linearity of frequency chirps in Frequency-Modulated Continuous-Wave (FMCW) LiDAR systems, resulting in improved metrological accuracy. The system is fully implemented on an easily accessible FPGA-based digital electronic platform (Red Pitaya STEMlab 125-14). A PC-based UI was developed to facilitate remote real-time control over key system parameters. The proposed closed-loop control reduces the Full-Width Half Maximum (FWHM) in frequency domain to 11 kHz, corresponding to a range resolution of 19.9 mm at a beat frequency of 2.45 MHz. Additionally, the system effectively suppresses disturbances in the modulation signal for frequencies up to 150 kHz, with stabilization settling within a single modulation period. This approach enables the use of lasers with nonlinear modulation slopes in FMCW LiDAR applications, even under fluctuating ambient conditions.
Source: Applied Physics B
Authors: Maria Schnuck, Yu Tian, Francisco Diaz Otero
Institutions: ETH Zurich, Universidade de Vigo
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,090
OpenAlex ID: W4416097909