VCSEL Detector Array Layout for Parallax-Free 3D Sensing

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Solution Overview

Problem

Existing 3D sensing technologies face challenges such as increased size, complexity, and limited functionality due to separate detectors and cameras, and self-mixing interferometry (SMI) with vertical-cavity surface-emitting lasers (VCSELs) are limited in determining object dimensions and shape.

Innovation Solution

Integration of a detector array with VCSELs, where each VCSEL includes an emitter and a photodetector, generating self-mixing interferometry signals, allowing for integrated detection of distance, velocity, and object dimensions through amplitude and frequency modulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate detectors and cameras are used for 3D sensing, then detection functionality is achieved, but device size and complexity increase

Engineering Contradiction:

Improvedetection functionalityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the emitter (VCSEL) and photodetector into a single integrated sensing element. The photodetector is positioned to receive reflected light at the same location where light is emitted, merging functions that were previously separated into distinct components. This integration reduces device complexity while maintaining 3D sensing capability through self-mixing interferometry.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If separate detectors and cameras are used for 3D sensing, then detection functionality is achieved, but manufacturing cost increases

Engineering Contradiction:

Improvedetection functionalityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

By integrating the photodetector and VCSEL emitter into a single element, the patent reduces the number of discrete components that need to be manufactured, assembled, and aligned. This merger simplifies the manufacturing process and reduces costs while achieving the same detection functionality that previously required separate detectors and cameras.

Inventive Principle:

Principle #5Merging (Combining)

3Difficulty of detecting and measuring

If detector is separate from emitter, then detection is possible, but parallax error occurs

Engineering Contradiction:

Improvedetection capabilityVSAvoidmeasurement precision

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent positions the photodetector at the same spatial location as the VCSEL emitter, creating a co-located detection system. This eliminates the baseline separation between emission and detection points, thereby eliminating parallax error and improving measurement precision for distance and position measurements.

Inventive Principle:

Principle #5Merging (Combining)

4Measurement precision

If self-mixing interferometry with VCSEL is used, then distance and velocity detection is achieved, but object dimension and shape determination is limited

Engineering Contradiction:

Improvedistance and velocity detectionVSAvoidobject dimension and shape determination

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs an array of multiple integrated VCSEL-photodetector elements, each capable of self-mixing interferometry. By segmenting the sensing function across multiple elements positioned at different locations, the system can determine not only distance and velocity but also object dimensions and shape through spatial analysis of return signals from different angles and positions.

Inventive Principle:

Principle #1Segmentation

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 smaller, less complex, and cost-effective 3D sensing by integrating photodetectors with emitters, reducing parallax and enabling determination of object dimensions and shape, with reduced size and complexity.

Implementation Method 1

The photodetector of each VCSEL of the plurality of VCSELs may be configured to generate the SMI signal based on at least one of: the emitted signal, the reflected signal, or any combination thereof

Methodology Applied

Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 2

the reflected signal may interfere with the emitted signal to cause a modulation

Methodology Applied

Scientific EffectOptical interference: Interference

Data Source

PatentEP4682583A1Sensing element with vcsel integrated detector array and self-mixing interferometry

Publication Date: 2026.01.21 II VI DELAWARE INC

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AI summary

Provided are sensing elements with at least one integrated detector array, methods of using such sensing elements, and systems including such sensing elements. An example sensing element includes a plurality of vertical-cavity surface-emitting lasers (VCSELs). Each VCSEL of the plurality of VCSELs includes an emitter and a photodetector. Each VCSEL of the plurality of VCSELs is configured to generate a self-mixing interferometry (SMI) signal.