Coherent Imaging Detector with Deflecting Elements
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Solution Overview
Problem
Current coherent imaging and lidar systems face challenges in achieving high-resolution, video frame rate distance images due to short measurement time per point and are not scalable to large numbers of pixels, while also struggling with speckle grains that reduce detection sensitivity.
Innovation Solution
An integrated detector with a matrix array of pixels and transmissive deflecting elements that can be individually oriented to optimize the spatial distribution of speckle grains, improving signal-to-noise ratio through a feedback loop, allowing for efficient detection of small speckle grains and scalable pixel arrays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional coherent imaging systems use fixed pixel arrays without speckle optimization, then device complexity is reduced, but detection sensitivity deteriorates due to small speckle grains not aligning with pixel surfaces
Solution Approach 1:
The patent introduces dynamically adjustable deflecting elements (such as micromirrors or prisms) in front of each pixel or pixel group that can be individually oriented to optimize the spatial distribution of speckle grains. This dynamic adjustment allows the system to adapt speckle patterns to match pixel positions, improving detection sensitivity without requiring a complete redesign of the detector architecture.
Solution Approach 2:
The patent implements feedback loops that use detection signals to control the orientation of deflecting elements. The system measures the current speckle distribution, compares it with optimal positioning, and adjusts the deflecting elements accordingly to maximize signal detection. This closed-loop control enables automatic optimization of speckle grain alignment with pixel surfaces.
2Measurement precision
If coherent imaging systems use sequential point-by-point scanning to achieve high resolution, then measurement precision is improved, but productivity deteriorates due to long acquisition times
Solution Approach 1:
The patent divides the detector into multiple pixel groups, with each group having its own deflecting element for independent speckle optimization. This segmentation allows parallel processing of different spatial regions, enabling high-resolution imaging across the entire field of view simultaneously rather than sequentially scanning each point.
Solution Approach 2:
The patent transitions from sequential one-dimensional scanning to parallel two-dimensional array detection. By using a matrix array of pixels with independent speckle optimization capabilities, the system captures distance information for the entire scene simultaneously, achieving video frame rate acquisition while maintaining high spatial resolution.
3Measurement precision
If coherent imaging systems use large aperture optics to capture more light, then detection sensitivity is improved, but speckle grain size decreases making detection more difficult
Solution Approach 1:
The patent introduces deflecting elements as intermediary components between the optical system and the pixel detector. These elements act as mediators that can dynamically redirect and concentrate speckle grains onto pixel surfaces, effectively decoupling the relationship between aperture size and speckle grain size. The deflecting elements ensure that even small speckle grains from large aperture systems are properly positioned for detection.
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
Enables high-resolution, fast acquisition of distance images with improved sensitivity and scalability, effectively addressing the limitations of existing systems by optimizing speckle grain distribution and detection.
Implementation Method 1
The interference of these two waves is detected by a photodetector PD, and the electrical signal at the output of the detector has an oscillating term called the beat signal Sb
Implementation Method 2
the electrical signal at the output of the detector has an oscillating term called the beat signal Sb
Data Source
AI summary
A detection device for a coherent imaging system includes a detector comprising a matrix array of pixels, each pixel comprising a photodetector component having a photosensitive surface, the detector being designed to be illuminated by a coherent beam, called the image beam consisting of grains of light called speckle grains, a matrix array of transmissive deflecting elements configured to be individually orientable by means of an electrical signal, so as to deflect a fraction of the image beam incident on the group, and thus modify the spatial distribution of the speckle grains in the plane of the photosensitive surface, each group of one or more pixels further comprising a feedback loop associated with the deflecting element and configured to actuate the deflecting element so as to optimize the signal-to-noise ratio from the light detected by the one or more photodetector components of the group of pixels, the feedback loop comprising a feedback circuit.