A team of scientists led by Professor Yongkang Dong from the National Key Laboratory of Laser Spatial Information at Harbin Institute of Technology, China, has proposed a multifunctional frequency modulated continuous wave (FMCW) LiDAR system capable of high-precision ranging and multi-parameter sensing. This novel technology, published in Light: Science & Applications (DOI: 10.37188/lam.2026.102), integrates 3D imaging with simultaneous measurements of environmental temperature, gas concentrations, and liquid density, addressing critical safety concerns in new energy vehicles and spacecraft.
Traditional FMCW LiDAR systems are limited to high-precision 3D imaging and cannot detect internal battery states or environmental parameters. In electric vehicles, thermal runaway of batteries poses a significant safety risk, and early warning requires coordinated monitoring of multiple parameters such as temperature, electrolyte density, and characteristic gases. Currently, these functions are performed by separate systems, leading to high complexity, elevated costs, and integration challenges. The new multifunctional LiDAR addresses this by detecting echo signals from both free space and optical fiber, enabling simultaneous imaging and sensing through a single demodulator.
In proof-of-concept experiments, the system successfully imaged a plastic plate with a "HIT" symbol placed 30 meters away, with adjustable resolution ranging from 0.3 cm to 1.2 cm. Simultaneously, the electrolyte density and temperature of a battery were measured with accuracies of 3×10⁻⁵ g/mL and 0.5 °C, respectively. The concentrations of gases critical for monitoring thermal runaway—C2H2, CO2, and CH4—were detected with limits of 0.07 ppm, 48 ppm, and 0.56 ppm, respectively.
By integrating FMCW LiDAR with optical frequency domain reflectometry (OFDR), the system leverages the same linearly modulated continuous light source for both free-space imaging and fiber-based sensing. This approach offers high spatial resolution and a large dynamic range, making it suitable for measuring strain, temperature, pressure, and gas concentration. The researchers explain that in the LiDAR module, the target distance is calculated from the optical path difference between the collimator reflection peak and the target reflection peak. The reflection spectra of fiber Bragg gratings (FBG), Fabry-Perot (FP) cavities, and multipass cells (MPC) are demodulated from their reflection peaks in the spatial domain via inverse Fourier transform.
The ability to simultaneously perform 3D imaging and multi-parameter sensing with a single system has significant implications for the safety of new energy vehicles. It can combine the key functions of automatic driving systems and battery management into one unit, reducing complexity and cost. The technology also holds promise for spacecraft applications, where monitoring environmental parameters and structural integrity is crucial.
The proposed multifunctional FMCW LiDAR represents a major step forward in integrated sensing and imaging, offering a new solution to enhance safety in emerging technologies.
