LIDAR Receiver Waveguide and Aperture Filtering for Background Noise
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Solution Overview
Problem
Light detectors, such as silicon photomultipliers, are susceptible to adverse background effects from extraneous light sources, which can affect measurement accuracy.
Innovation Solution
A system using a lens, opaque material with an aperture, waveguide, and mirror to focus and guide light to an array of detectors, selectively filtering background light and increasing detection area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple light detectors are arranged into arrays to detect light over a substantial geometric area, then the detection area is improved, but the susceptibility to adverse background effects increases
Solution Approach 1:
The system divides the detection area into multiple segments by using an array of individual light detectors arranged in specific patterns. Each detector operates independently and can be selectively activated or weighted based on the position and intensity of incoming light, allowing the system to maintain large detection area while reducing background interference through selective processing of signals from individual segments.
Solution Approach 2:
Different regions of the detection array are assigned different functional characteristics. The system uses varying detector densities, sensitivities, or activation thresholds in different spatial locations to optimize both detection area coverage and background rejection capability. Areas with higher background interference may use detectors with different characteristics than those in lower-interference regions.
2Measurement precision
If light detectors are made sensitive to low intensities of light, then the detection quality is improved, but the susceptibility to extraneous light from outside sources increases
Solution Approach 1:
The system incorporates feedback mechanisms that continuously monitor the detection signals and compare them against expected patterns. When extraneous light causes false signals or saturates detectors, the feedback system adjusts detector activation thresholds, applies signal rejection algorithms, or modulates detector sensitivity in real-time to maintain detection quality while rejecting background interference.
Solution Approach 2:
The system uses periodic modulation or time-gated detection where detectors are activated in specific time windows or cycles. By synchronizing detection with expected signal arrival times and using periodic gating, the system can distinguish between genuine low-intensity signals and random background noise, maintaining sensitivity while reducing extraneous light susceptibility.
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
Reduces background light interference, enhancing measurement accuracy and reliability of light detectors by maintaining them in an unsaturated state.
Implementation Method 1
a lens disposed relative to a scene and configured to focus light from the scene
Implementation Method 2
The waveguide guides the received light toward a second side of the waveguide opposite to the first side
Implementation Method 3
a mirror disposed along a propagation path of the guided light. The mirror reflects the guided light toward the third side of the waveguide
Implementation Method 4
an array of light detectors that detects the reflected light propagating out of the third side of the waveguide
Data Source
AI summary
The present disclosure relates to limitation of noise on light detectors using an aperture. One example implementation includes a system. The system includes a lens disposed relative to a scene. The lens focuses light from the scene. The system also includes an opaque material that defines an aperture. The system also includes a waveguide having a first side that receives light focused by the lens and transmitted through the aperture. The waveguide guides the received light toward a second side of the waveguide opposite to the first side. The waveguide has a third side extending between the first side and the second side. The system also includes a mirror that reflects the guided light toward the third side of the waveguide. The system also includes an array of light detectors that detects the reflected light propagating out of the third side.