Optical Frequency Comb LIDAR for Parallel Velocity Ranging
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Solution Overview
Problem
Existing LIDAR technologies face challenges in achieving high image acquisition speed while providing robustness, precision, and instantaneous velocity measurements.
Innovation Solution
A LIDAR device utilizing a laser light source, non-linear optical element, and diffractive element to generate a comb-like frequency spectrum for parallelized distance and velocity measurements, with a detector to measure frequency modulation of reflections for simultaneous target position analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If FMCW LIDAR technology is used to provide instantaneous velocity information and improved robustness, then measurement precision and reliability are improved, but acquisition speed decreases
Solution Approach 1:
The invention segments the optical frequency spectrum into multiple comb modes that can be independently directed to different target positions. Each comb mode carries frequency-modulated light for parallel FMCW LIDAR measurements, enabling simultaneous velocity and distance measurements across multiple spatial channels, thus resolving the contradiction between measurement precision and acquisition speed.
Solution Approach 2:
The invention introduces a spectral dimension by utilizing multiple optical frequency comb modes. Instead of sequentially scanning single-frequency lasers, the system employs parallel frequency channels that are spatially separated and directed to different target positions, adding a spectral dimension to achieve both high precision and fast acquisition.
2Productivity
If TOF LIDAR uses array of individual lasers for parallelized image scanning to increase speed, then acquisition speed is improved, but only distance information is provided without instantaneous velocity information
Solution Approach 1:
The invention makes each optical frequency comb mode serve multiple functions: it acts as both a distance measurement probe and a velocity measurement probe simultaneously through frequency modulation. The same parallelized comb modes that enable fast scanning also provide instantaneous velocity information via Doppler effect, achieving both high speed and comprehensive measurement capability.
3Measurement precision
If multiple comb modes are used to illuminate a single target position for coherent stitching, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
Instead of using multiple comb modes to illuminate a single target position (which increases complexity), the invention inverts the approach by assigning each comb mode to a different target position. This spatial-spectral mapping simplifies the system architecture while maintaining high measurement accuracy through parallelized FMCW LIDAR measurements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves high image acquisition speed with improved precision and robustness, enabling efficient parallelized detection of distance and velocity.
Implementation Method 1
The non-linear optical element is configured to receive the first laser light and generate therefrom second laser light having a comb-like frequency spectrum with a plurality of second laser frequencies
Implementation Method 2
The diffractive element is configured to spatially separate the second laser light according to the second laser frequencies and direct the spatially separated second laser light towards a ranging region
Implementation Method 3
the FMCW LIDAR technology and can also provide instantaneous velocity information by Doppler effect measurements
Data Source
AI summary
In a LIDAR device (100) a laser light source (110) generates first laser light having a first laser frequency which is frequency modulated with a first frequency modulation. A non-linear optical element (120) receives the first laser light and generates therefrom second laser light having a comb-like frequency spectrum with a plurality of second laser frequencies which are each frequency modulated with a second frequency modulation defined by the first frequency modulation. A frequency excursion of the second frequency modulation is smaller than a spacing of the second laser frequencies. A diffractive element (140) spatially separates the second laser light according to the second laser frequencies and directs the spatially separated second laser light towards a ranging region (200), with each of the second laser frequencies being directed towards a corresponding spatially distinct target position in the ranging region (200). A detector (150) receives reflections of the second laser light from the ranging region (200) and measures, by simultaneously detecting a frequency modulation of the reflections for each of the second laser frequencies, a distance and/or a velocity at the target position corresponding to the second laser frequency.