Multi-Pixel Waveguide Receiver for Optical Speckle Interference

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Solution Overview

Problem

In lidar systems, the spatial phase variations of scattered light can lead to destructive interference when coupled into optical transmission media, resulting in loss of information and inaccurate measurements due to the varying spatial phase across the receiving area.

Innovation Solution

A multi-pixel waveguide optical receiver with pixels smaller than the expected optical speckle size, combined with a combiner that supports multiple modes, reduces destructive interference by ensuring uniform spatial phase across each pixel and combines optical fields from different pixels into a single output, thereby preserving light energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a single large pixel receiver is used, then the receiving area is maximized, but spatial phase variations cause destructive interference and information loss

Engineering Contradiction:
Improvereceiving areaVSAvoidinformation loss
Core Design Contradiction:
Area of stationary objectVSLoss of information

Solution Approach 1:

The receiver is divided into multiple pixels instead of using a single large pixel. Each pixel has a size smaller than the expected optical speckle size, ensuring uniform spatial phase across each pixel. This segmentation prevents destructive interference within each pixel while maintaining a large total receiving area through the combined array of pixels.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If multiple pixels smaller than speckle size are used, then destructive interference is reduced and measurement accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple pixels are combined into a single array structure that functions as one integrated receiver. The combiner merges the optical fields from all pixels into a unified output signal, allowing the system to achieve high measurement accuracy through multiple small pixels while presenting a simplified interface to the rest of the lidar system.

Inventive Principle:
Principle #5Merging (Combining)

3Loss of energy

If optical fields from multiple pixels are combined into a single output, then light energy is preserved and measurement accuracy is improved, but the combiner complexity increases

Engineering Contradiction:
Improvelight energy lossVSAvoidcombiner complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

A combiner is introduced as an intermediary component between the multi-pixel receiver and the photodetector. The combiner efficiently merges optical fields from multiple pixels into a single output, preserving light energy and improving measurement accuracy. This intermediary handles the complexity of multi-pixel integration, keeping the overall system design manageable.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhances the accuracy of light measurements by minimizing destructive interference, allowing for more reliable ranging information and improved navigation solutions in lidar systems.

Implementation Method 1

an emitter that emits laser light towards a surface

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

a receiver that passively receives reflected laser light that is a portion of the laser light reflected from the surface

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a combiner configured to combine optical fields from each pixel in the multiple pixels into an output that supports a number of modes that is equal to a number of pixels in the multiple pixels

Methodology Applied
Scientific EffectOptical field superposition: Interference

Implementation Method 4

a photodetector configured to receive light from the output

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP4067932B1Multi-pixel waveguide optical receiver
Publication Date: 2024.06.05 HONEYWELL INTERNATIONAL INC
  • EP4067932B1 patent drawingFigure 1
  • EP4067932B1 patent drawingFigure 2
  • EP4067932B1 patent drawingFigure 3

AI summary

Systems and embodiments for a multi-pixel waveguide optical receiver are described herein. In certain embodiments, a system includes an emitter that emits laser light towards a surface. The system also includes a receiver that passively receives reflected laser light that is a portion of the laser light reflected from the surface, wherein the receiver has multiple pixels having a size that is smaller than an expected optical speckle size, wherein the expected optical speckle size corresponds to a region on the receiver where the reflected laser light has a substantially uniform spatial phase. Additionally, the system includes a combiner configured to combine optical fields from each pixel in the multiple pixels into an output that supports a number of modes that is equal to a number of pixels in the multiple pixels. Moreover, the system includes a photodetector configured to receive light from the output.