Spatio-spectral 4D coherent ranging using a flutter-wavelength-swept laser.

Area of Science:

• Optical Engineering
• Laser Technology
• Remote Sensing

Background:

• Frequency-modulated continuous-wave (FMCW) LiDAR is a key technology for 3D distance and velocity measurements.
• Conventional LiDAR systems face limitations in measurable distance due to unidirectional wavelength sweeping.
• Accurate real-time 4D imaging requires advanced scanning and measurement capabilities.

Purpose of the Study:

• To develop a spatio-spectral coherent LiDAR system capable of simultaneous axial ranging and lateral scanning.
• To overcome the measurable distance limitations of traditional FMCW LiDAR.
• To achieve high-resolution, real-time four-dimensional (4D) imaging.

Main Methods:

• Implementation of a novel flutter-wavelength-swept laser (FWSL) for decoupled bidirectional wavelength modulation.
• Utilizing a wide spectral bandwidth (160 nm) for sequential sampling.
• Integration of an acousto-optic scanner for synchronized lateral beam scanning.

Main Results:

• The FWSL successfully decoupled wavelength modulation, enabling extended measurable distances.
• Simultaneous measurement of distance and velocity was achieved over a broad spectral range.
• The developed spatio-spectral coherent LiDAR system demonstrated high-resolution ranging and real-time 4D imaging at 10 Hz.

Conclusions:

• The proposed spatio-spectral coherent LiDAR system offers a significant advancement in long-range 3D and 4D imaging.
• The FWSL technology effectively overcomes previous distance limitations in FMCW LiDAR.
• This optimized system provides robust performance even in challenging environmental conditions.