FMCW Lidar Research Articles

Investigation and comparison of sensitivity of LiDAR to laser physical parameters at 750 m using different detection techniques

In this paper, the different detection techniques are investigated- Direct Detection and Coherent Heterodyne Detection on FMCW LiDAR system using Optisystem package. The results of investigations done are included to see the influence of laser physical parameters- Active Length, Active Layer Width and Reflectivity on LiDAR performance parameters- Power Received, SNR at photodetector output and beam parameters- Beam Diameter and Beam Divergence. This investigation is done using DFB laser and FP laser in place of CW laser in different reference models for different detection techniques. The optimised values of laser physical parameters are obtained where the DFB Laser and FP Laser provide the same performance as that of the CW Laser.

Velocity Measurement in Automotive Sensing: How FMCW Radar and Lidar Can Work Together

Autonomous vehicles (AVs) depend on an intricate network of camera, radar, lidar, and inertial sensors to navigate safely. Discussing the merits and drawbacks of individual sensors is one of the more consistent water-cooler topics in the autonomous driving industry. Although this sensor face-off is entertaining, it is sometimes more useful to consider how two sensors can work together. I will discuss two sensors that can directly sense velocity in the context of future AV capability.

气溶胶环境下FMCW与脉冲激光探测性能对比

气溶胶环境下FMCW与脉冲激光探测性能对比

气溶胶环境下FMCW与脉冲激光探测性能对比

气溶胶环境下FMCW与脉冲激光探测性能对比

Frequency-modulated comb LIDAR

Frequency-modulated continuous-wave LIDAR (FMCW LIDAR) has been widely used for both scientific and industrial tools. Here, in this report, a new class of LIDAR technique based on an optical frequency comb, named frequency-modulated comb LIDAR (FMcomb LIDAR), is proposed. Instead of using one carrier such as FMCW LIDAR, the multiple carriers from an optical frequency comb are used in FMcomb LIDAR. Because of the correlation between comb modes, each frequency-scanned comb mode can be coherently stitched, thus allowing for a resolution equivalent to scanning by many comb modes while scanning only by the comb mode spacing. In a proof-of-concept experiment, three comb modes from an electro-optic frequency comb (EO comb) are coherently stitched, showing Fourier-transform limited resolution (defined as FWHM linewidth) of 10 ps (i.e., 1.5 mm in air) for about 65 ns delay. The obtained resolution is three-times higher than that of conventional FMCW LIDAR when the same scan range is considered.

Lidar System Architectures and Circuits

3D imaging technologies are applied in numerous areas, including self-driving cars, drones, and robots, and in advanced industrial, medical, scientific, and consumer applications. 3D imaging is usually accomplished by finding the distance to multiple points on an object or in a scene, and then creating a point cloud of those range measurements. Different methods can be used for the ranging. Some of these methods, such as stereovision, rely on processing 2D images. Other techniques estimate the distance more directly by measuring the round-trip delay of an ultrasonic or electromagnetic wave to the object. Ultrasonic waves suffer large losses in air and cannot reach distances beyond a few meters. Radars and lidars use electromagnetic waves in radio and optical spectra, respectively. The shorter wavelengths of the optical waves compared to the radio frequency waves translates into better resolution, and a more favorable choice for 3D imaging. The integration of lidars on electronic and photonic chips can lower their cost, size, and power consumption, making them affordable and accessible to all the abovementioned applications. This review article explains different lidar aspects and design choices, such as optical modulation and detection techniques, and point cloud generation by means of beam-steering or flashing an entire scene. Popular lidar architectures and circuits are presented, and the superiority of the FMCW lidar is discussed in terms of range resolution, receiver sensitivity, and compatibility with emerging technologies. At the end, an electronic-photonic integrated circuit for a micro-imaging FMCW lidar is presented as an example.