Waveguide Diffuser for Light Detection Using Aperture

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Solution Overview

Problem

Existing light detection systems, such as LIDAR devices, face challenges in effectively reducing background light noise while maintaining sensitivity to low-intensity light signals.

Innovation Solution

The system employs a lens to focus light from a scene, an aperture defined within an opaque material to selectively filter light, and a waveguide that guides light towards an array of light detectors, allowing for increased detection area and reduced background noise.

Engineering Contradictions & Design Principles

VSEngineering 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 increased, but the susceptibility to background light noise increases

Engineering Contradiction:
Improvedetection areaVSAvoidbackground light noise
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a temporal dimension to light detection by using time-correlated single photon counting (TCSPC). Detectors are arranged in arrays that can be sequentially activated in different time gates, allowing the system to accumulate detection area across multiple time windows while maintaining noise rejection through temporal discrimination of signal photons from background photons.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The system performs preliminary temporal gating before full detection array activation. By pre-synchronizing detector activation with expected signal arrival times and using time-correlated counting, the system prepares the detection array to selectively respond to signal photons within specific time windows, thereby reducing background noise accumulation across the full detection area.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If light detectors are made sensitive to low intensities of light, then the sensitivity to low-intensity light signals is enhanced, but the susceptibility to background light effects increases

Engineering Contradiction:
Improvesensitivity to low-intensity lightVSAvoidbackground light effects
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent employs periodic time-gated detection cycles where detectors are activated in synchronized bursts corresponding to expected signal return times. By repeatedly cycling through time gates and accumulating time-correlated photon counts, the system enhances sensitivity to low-intensity periodic signals while rejecting non-periodic background light through temporal averaging.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses time-correlated single photon counting with feedback mechanisms that adjust detection timing and gating based on measured signal characteristics. By continuously monitoring photon arrival times and adjusting time gate synchronization, the system maintains high sensitivity to low-intensity signals while dynamically adapting to reject background light effects.

Inventive Principle:
Principle #23Feedback

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

This configuration significantly reduces background light noise, enhances the signal-to-noise ratio, and maintains high sensitivity to low-intensity light signals, thereby improving the accuracy of light detection and ranging (LIDAR) measurements.

Implementation Method 1

The waveguide has a core region and a cladding layer that extends along the fourth side and portions of the other three sides... guiding, by the waveguide, the received light toward a second side of the waveguide

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a lens disposed relative to a scene and configured to focus light from the scene

Methodology Applied
Scientific EffectOptical focusing: Lens

Implementation Method 3

an array of light detectors that intercepts and detects light propagating out of the third side of the waveguide

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3548853B1Waveguide diffuser for light detection using an aperture
Publication Date: 2025.01.29 WAYMO LLC
  • EP3548853B1 patent drawingFigure 1A
  • EP3548853B1 patent drawingFigure 1B
  • EP3548853B1 patent drawingFigure 2

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 aperture defined within an opaque material. 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 an array of light detectors that intercepts and detects light propagating out of the third side of the waveguide.