Metasurface Structured Light 3D Imaging Speckle Reduction
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Solution Overview
Problem
Dynamic structured light 3D imaging systems face limitations in precision and robustness due to laser speckles and limited energy from single-mode edge-emitting lasers, which restrict the signal-to-noise ratio and operating distance.
Innovation Solution
A metasurface-based structured light 3D imaging system utilizing a semiconductor laser, beam homogenizer, condenser, and MEMS micromirror for precise control of the laser beam, with micro-nano structures on the beam homogenizer and condenser to reduce speckles and enhance light field control, improving precision and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single-mode edge-emitting laser is used, then the system size is reduced, but the energy of the light source is limited and the signal-to-noise ratio cannot be increased
Solution Approach 1:
The patent segments the laser system into multiple independent laser units (array configuration) instead of using a single laser. Each laser unit operates independently, and their combined output provides sufficient energy while maintaining the compact form factor of individual units. This segmentation allows the system to achieve high power output without increasing overall system size proportionally.
Solution Approach 2:
The patent transitions from a single-point laser source to a two-dimensional array of laser units. This dimensional expansion allows the system to increase total energy output by adding more units in the array plane, rather than increasing the size of a single laser unit, thus maintaining compactness while achieving higher power.
2Measurement precision
If a laser source is used, then the system achieves high precision, but laser speckles are introduced which compromise precision
Solution Approach 1:
The patent divides the single laser source into multiple independent laser units in an array. Each unit produces its own speckle pattern, and the superposition of multiple independent speckle patterns results in a more uniform intensity distribution, effectively reducing the harmful effects of laser speckles while maintaining the precision benefits of laser illumination.
Solution Approach 2:
The patent uses multiple laser units with identical characteristics arranged in an array, ensuring homogeneous performance across all units. This homogeneity, combined with the spatial distribution, creates a uniform overall illumination field that minimizes speckle artifacts while maintaining laser precision.
3Length of stationary object
If the light source energy is increased, then the operating distance is extended, but the system complexity increases
Solution Approach 1:
The patent uses multiple simple laser units arranged in an array to achieve the energy required for extended operating distance. Each unit remains simple in design, and the array configuration provides a straightforward scaling approach that increases energy output without proportionally increasing system complexity, as the units can be integrated using standard array mounting techniques.
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 system achieves high-precision 3D imaging with improved power and robustness, reducing laser speckles and expanding the operating range while maintaining a small size and low cost.
Implementation Method 1
The metasurface is a 2D planar structure, which is formed by arranging artificial atoms with a special electromagnetic attribute in a certain manner, can realize flexible control of the amplitude, phase and polarization of incident light
Implementation Method 2
a beam homogenizer, a condenser, a cylindrical mirror and a MEMS micromirror are sequentially arranged in front of the semiconductor laser in an incident direction; micro-nano structures, which are fabricated by lithography, electron beam processing or nanoimprint lithography, are arranged on surfaces of the beam homogenizer and the condenser
Implementation Method 3
a beam homogenizer, a condenser, a cylindrical mirror and a MEMS micromirror are sequentially arranged in front of the semiconductor laser in an incident direction
Data Source
AI summary
Disclosed are a metasurface-based structured light 3D imaging system and method, which use a metasurface-based control device to realize high-quality control of a laser beam, use a MEMS micromirror to scan and project the laser beam, and realize high-precision reconstruction of 3D information of the surface of an object together with related structured light design and demodulation methods. The invention realizes fine control of a structured light, improves the quality of a structured light field, reduces laser speckles and improves power, thus improving 3D imaging precision and robustness.