Optical Frequency Comb FMCW LiDAR for Parallel Distance and Velocity Sensing

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Solution Overview

Problem

Existing laser ranging and detection (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 measurements, enabling simultaneous distance and velocity detection through spatially separated laser beams.

Engineering Contradictions & Design Principles

VSEngineering 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 image acquisition speed decreases

Engineering Contradiction:
Improvevelocity measurement precisionVSAvoidimage acquisition speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent segments the optical frequency comb into multiple frequency channels, each directed to different spatial positions. This allows parallel FMCW measurements across multiple target positions simultaneously, achieving both high velocity measurement precision and fast image acquisition speed by processing multiple spatial locations in parallel rather than sequentially

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a frequency dimension by using an optical frequency comb with multiple discrete frequency channels. Each frequency channel is spatially separated and directed to a different target position, adding a frequency dimension to the traditional spatial scanning approach. This enables parallel measurements across multiple positions, resolving the speed-precision contradiction

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If TOF LIDAR system utilizes array of individual lasers for parallelized image scanning, then image acquisition speed is improved, but only distance information is provided without instantaneous velocity information

Engineering Contradiction:
Improveimage acquisition speedVSAvoidvelocity measurement capability
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent makes a single frequency-modulated laser source perform multiple functions by generating an optical frequency comb that provides both distance and velocity information simultaneously. The frequency-modulated comb enables FMCW measurements for velocity detection while maintaining parallel scanning capability for fast image acquisition, making the system universally capable of both TOF and FMCW measurements

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If FMCW LIDAR system is implemented with frequency-modulated laser, then instantaneous velocity information and robustness are improved, but device complexity increases due to precise frequency modulation requirements

Engineering Contradiction:
Improverobustness against stray lightVSAvoidfrequency modulation precision requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a photonic resonator to self-generate the optical frequency comb from a single frequency-modulated laser. The resonator's natural resonance properties automatically create the multi-frequency comb structure without requiring complex external modulation devices, allowing the system to achieve robust FMCW measurements while reducing device complexity through self-organization

Inventive Principle:
Principle #25Self-service

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, allowing for efficient parallelized detection of distance and velocity measurements.

Implementation Method 1

The non-linear optical element is comprises at least one photonic resonator configured to receive the first laser light and generate therefrom second laser light having a comb-like frequency spectrum

Methodology Applied
Scientific EffectNon-linear optical effect:

Implementation Method 2

first laser light having a first laser frequency, which is frequency-modulated with a first frequency modulation

Methodology Applied
Scientific EffectFrequency modulation: Phase Modulation

Implementation Method 3

The diffractive element is configured to spatially separate the second laser light to multiple beams according to the second laser frequencies

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 4

the FMCW LIDAR technology and can also provide instantaneous velocity information by Doppler effect measurements

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP4062192B1Optical frequency comb based parallel FM lidar
Publication Date: 2025.12.24 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
  • EP4062192B1 patent drawingFigure 1
  • EP4062192B1 patent drawingFigure 2A~2B
  • EP4062192B1 patent drawingFigure 3A~3B

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.