LiDAR receives different signals with micron accuracy

Light and field detection (LiDAR) is known as it offers high accuracy, and shows promising prospects in autonomous vehicles and various fields. LiDAR’s traditional modular frequency continuous wave (FMCW) range is based on heterodyne detection, measuring unknown distance by extracting the frequency of the interference signal. However, such an approach suffers from absence frequency modeling (FM), which leads to erroneous field results.

As a result of the unrelated relationship between laser waveguide and injection wavelength, the spectrum of the pulse signal is extended even though the laser emits a triangle signal.

To solve the problem, a research team led by Professor Zhang Wenfu from the Xi’an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences (CAS) proposed a new approach that samples the field signals at equal frequency times using a microresonator soliton comb. The results were published in Optics Letters.

In the new system, a correct pulse frequency is not required so that the data processing step is simplified. Instead, the unknown distance is provided by the linear relationship between the measured frequency interval and the corresponding level of the range signal.

Moreover, thanks to the constant frequency characteristics of the soliton comb ensuring accurate sampling, the system is virtually unclear in terms of external blocking. The optical path of the system is almost unaffected by ambient temperature and humidity since the long optical fiber has not been used.

The test shows that the range error is less than 20 μm at a measurement distance of 2 meters, the promising result and the advantages described above show that the method has a strong application ability. -work recommended in precision manufacturing.