Diffractive Optical Element for Uniform LiDAR Array Detection

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Solution Overview

Problem

Existing LiDAR systems with photosensor arrays suffer from non-uniform distribution of returning laser beams due to the Lambertian effect and fabrication limitations, leading to optical loss and distorted imaging.

Innovation Solution

Incorporating a diffractive optical element that splits the returning laser beam into multiple beams with uniform intensity distribution, aligning them with the photosensor array's sensitive elements to minimize gaps and optical loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a photosensor array is used to achieve sub-pixelization and increased imaging resolution, then imaging resolution is improved, but non-uniform light distribution causes optical loss and distorted imaging

Engineering Contradiction:

Improveimaging resolutionVSAvoidimaging accuracy

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

A diffractive optical element is introduced as an intermediary component between the returning laser beam and the photosensor array. This element redistributes the non-uniform light intensity into multiple beams with more uniform distribution, ensuring that light is properly directed onto sensitive elements rather than falling into gaps, thus maintaining both high resolution and accurate imaging

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The diffractive optical element changes the spatial distribution parameter of the light beam by diffracting it into multiple beams. This parameter transformation converts the non-uniform single beam into multiple beams with uniform intensity distribution across different sections of the photosensor array, resolving the contradiction between resolution and imaging accuracy

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the laser beam size is decreased to increase imaging resolution, then imaging resolution is improved, but the emitted laser beam size cannot always be decreased due to system limitations

Engineering Contradiction:

Improveimaging resolutionVSAvoidlaser beam size

Core Design Contradiction:

Measurement precisionVSLength of moving object

Solution Approach 1:

The diffractive optical element segments the single returning laser beam into multiple beams that are distributed across different sections of the photosensor array. This segmentation allows the system to achieve high imaging resolution through sub-pixelization without requiring the emitted laser beam to be extremely small, thus resolving the contradiction between resolution and beam size constraints

Inventive Principle:

Principle #1Segmentation

3Area of stationary object

If sensitive elements are placed close together to cover more area, then detection coverage is improved, but fabrication limitations create gaps between sensitive areas causing optical loss

Engineering Contradiction:

Improvedetection coverageVSAvoidoptical loss

Core Design Contradiction:

Area of stationary objectVSLoss of energy

Solution Approach 1:

The diffractive optical element acts as a mediator that redistributes the light beam to account for the gaps between sensitive elements. By creating multiple diffracted beams with specific angular distributions, it ensures light is directed onto sensitive areas rather than falling into gaps, reducing optical loss while maintaining wide detection coverage

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The diffractive optical element creates local quality variations in the light distribution by directing different portions of the diffracted beams to different sections of the photosensor array. This ensures that light intensity is optimized for each local region covered by sensitive elements, maximizing detection efficiency across the entire array area

Inventive Principle:

Principle #3Local quality

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

Enhances imaging resolution and accuracy by ensuring uniform light intensity distribution across the photosensor array, preventing pixel loss and distortion.

Implementation Method 1

a diffractive optical element configured to diffract the optical signal returning from the environment to form a plurality of beams focusing at a plurality of spots on a focal plane

Methodology Applied

Scientific EffectDiffraction: Diffraction

Data Source

PatentUS12461208B2Diffractive light distribution for photosensor array-based lidar receiving system

Publication Date: 2025.11.04 BEIJING VOYAGER TECH CO LTD

AI summary

Embodiments of the disclosure provide an optical sensing system containing a diffractive optical element, and an optical sensing method using the same. For example, the optical sensing system includes a laser emitter configured to emit an optical signal. The optical sensing system further includes a steering device configured to direct the emitted optical signal toward an environment surrounding the optical sensing system. The optical sensing system additionally includes a diffractive optical element configured to diffract the optical signal returning from the environment to form a plurality of beams focusing at a plurality of spots on a focal plane. The optical sensing system additionally includes a photosensor array placed at the focal plane, configured to detect the plurality of beams diffracted by the diffractive optical element at the plurality of spots, wherein the photosensor array comprises a plurality of sensitive elements.