Diffractive Structured Light Decoding for Fast 3D Depth Sensing

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Solution Overview

Problem

Existing three-dimensional perception methods face challenges in directly acquiring depth information using optical systems, leading to heavy computational burdens and slow processing speeds due to complex post-processing requirements, especially in applications like automatic driving and virtual reality.

Innovation Solution

An all-optical intelligent computing system that encodes depth information into a spatial pattern of structured light using diffractive surfaces, which are then decoded into output light intensity through optimized optical interconnections, allowing direct three-dimensional map recording without post-processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional optical systems are used for three-dimensional perception, then depth information can be acquired, but heavy computational burdens and slow processing speeds occur due to complex post-processing requirements

Engineering Contradiction:
Improveprocessing speedVSAvoidcomputational burden
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces electronic computational systems with an all-optical computing system. Diffractive surfaces perform depth encoding and decoding operations optically rather than computationally, eliminating the need for heavy post-processing. The optical system directly maps depth information to spatial patterns and back to intensity distributions, achieving real-time three-dimensional perception without electronic computation bottlenecks.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces diffractive surfaces as intermediary components that mediate between the input light field and the output image. These diffractive surfaces encode depth information into structured light patterns and decode them into intensity distributions, serving as optical transformers that simplify the overall system complexity while maintaining functional capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If all-optical diffractive surfaces are used for depth detection, then high-speed and low-power three-dimensional perception is achieved, but the system complexity in terms of optical component arrangement increases

Engineering Contradiction:
Improvepower consumptionVSAvoidoptical component arrangement
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent divides the optical system into distinct functional modules: a light source module, an encoding diffractive surface module, an optical element module, a decoding diffractive surface module, and a detection module. Each module performs a specific function in the depth detection process, making the complex optical system more manageable and easier to implement while maintaining low power consumption through efficient optical computing.

Inventive Principle:
Principle #1Segmentation

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

Achieves high-speed, low-power three-dimensional perception by directly capturing depth information through optical means, reducing computational load and enabling applications such as ultra-fast obstacle avoidance and low-power unmanned systems.

Implementation Method 1

an encoding diffractive surface consists of a phase modulator based on encoding phase modulation information, and the encoding diffractive surface is configured to modulate a wave-front phase based on the laser beam to generate a structured light with spatial pattern varying with depth

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

a decoding diffractive surface consists of a phase modulator based on decoding phase modulation information, and the decoding diffractive surface is configured to map depth information in the structured light reflected by the object to a light intensity of an output plane

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 3

The reference light inputting module includes a solid state laser with a working wavelength, and the solid state laser is configured to generate a laser beam

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 4

The three-dimensional information acquisition module is configured to obtain light intensity information on the output plane by using a photodetector for depth information acquisition

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP4545905B1All-optical intelligent computing three-dimensional perception system and device
Publication Date: 2026.02.11 TSINGHUA UNIVERSITY
  • EP4545905B1 patent drawingFigure 1~2
  • EP4545905B1 patent drawingFigure 3~4
  • EP4545905B1 patent drawingFigure 5~6

AI summary

An all-optical intelligent computing three-dimensional perception system, comprising: a reference light inputting module (111) including a solid state laser configured to generate a laser beam; an all-optical structured light encoding module (112) including an encoding diffractive surface configured to modulate a wave-front phase based on the laser beam to generate a structured light with a spatial pattern varying with depth; a structured light illuminating module (113) including a plurality of optical elements configured to irradiate the generated structured light onto a surface of an object; an all-optical reflected light decoding module (114) including a decoding diffractive surface configured to map depth information in the structured light reflected by the object to a light intensity of an output plane; and a three-dimensional information acquisition module (115) configured to obtain light intensity information on the output plane by using a photodetector for a depth information acquisition to achieve a three-dimensional perception.