Microlens Array LiDAR Optics to Reduce Residue Reflections
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Solution Overview
Problem
Existing LiDAR systems face challenges in matching the emission angles of optical antennas with the acceptance angles of imaging lenses, leading to residue reflections that hinder target signal detection, especially at longer distances, due to fabrication process sensitivities and limited tolerance in emission angles.
Innovation Solution
Incorporating a microlens array between the imaging lens and the focal plane optical antenna array, which is anti-reflection-coated and positioned to transform the emission angles of optical antennas to match the chief ray angles of the lens, allowing for precise alignment and reduced reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the emission angles of optical antennas are tailored to match the acceptance angles of the imaging lens, then the detection precision of target signals is improved, but the system becomes sensitive to fabrication process variations and the complexity of angle matching increases
Solution Approach 1:
A microlens array is introduced as an intermediary component between the optical antenna array and the imaging lens. Each microlens is positioned at a specific offset from its corresponding optical antenna to transform the emission angles to match the chief ray angles of the imaging lens. This intermediary structure decouples the angle matching requirement from the fabrication process of the optical antennas themselves, reducing sensitivity to manufacturing variations while maintaining detection precision.
2Object-generated harmful factors
If the emission angles of optical antennas are tailored to match the acceptance angles of the imaging lens, then residue reflections are reduced, but the device complexity increases due to precise angle matching requirements
Solution Approach 1:
The microlens array serves as a mediator that automatically performs the angle transformation function. Instead of directly tailoring each optical antenna's emission angle to match the lens acceptance angles, the microlenses handle this function through their optical properties and positioning. This reduces device complexity by separating the angle matching function from the optical antenna design itself.
Solution Approach 2:
The system changes the optical parameters (emission angles) of the optical antenna array through the intervention of the microlens array. By adjusting the position and focal properties of the microlenses, the emission angles are transformed to match the chief ray angles of the imaging lens, thereby reducing residue reflections without requiring direct modification of the optical antennas.
3Manufacturing precision
If microlens array is introduced to transform emission angles, then the matching between antenna emission angles and lens acceptance angles is improved, but the device complexity increases due to additional components
Solution Approach 1:
The angle matching function is segmented and distributed across multiple microlenses in the microlens array. Each microlens handles the angle transformation for its corresponding optical antenna, allowing for modular design and fabrication. This segmentation enables better control over angle matching precision while managing system complexity through modular architecture.
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 microlens array effectively matches emission angles with the lens's acceptance angles, reducing residue reflections and enhancing the detection of target signals across various distances by optimizing beam divergence and chief ray angles, thereby improving the efficiency and accuracy of LiDAR imaging.
Implementation Method 1
the microlens array is positioned so as to transform an emission angle from a corresponding optical antenna to match a chief ray angle of the lens
Implementation Method 2
the microlens array, which is anti-reflection-coated and positioned to transform the emission angles of optical antennas
Data Source
AI summary
The present disclosure is directed to imaging LiDARs with optical antennas fed by optical waveguides. The optical antennas can be activated through an optical switch network that connects the optical antennas to a laser source to a receiver. A microlens array is positioned between a lens of the LiDAR system and the optical antennas, the microlens array being positioned so as to transform an emission angle from a corresponding optical antenna to match a chief ray angle of the lens. Methods of use and fabrication are also provided.