Surface Emitting Laser Device Crosstalk Reduction

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Solution Overview

Problem

Surface emitting laser devices face challenges in reducing crosstalk between light-emitting elements and forming dark lines between adjacent elements, while also requiring high heat dissipation performance due to increased heat generation compared to LEDs.

Innovation Solution

The device incorporates a wavelength converter with integrated wavelength conversion plates and a light absorption layer, along with a light reflection film, to minimize crosstalk and dark line formation, and utilizes a bonding metal layer and light reflection film for efficient heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If surface emitting laser elements are arranged in an array to save space, then device compactness is improved, but crosstalk of light between elements increases

Engineering Contradiction:
Improvedevice compactnessVSAvoidcrosstalk of light
Core Design Contradiction:
Volume of moving objectVSObject-generated harmful factors

Solution Approach 1:

A light absorption layer is introduced as an intermediary component between adjacent laser elements. This layer selectively absorbs stray light that would otherwise travel to neighboring elements, thereby reducing crosstalk while maintaining the compact array configuration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful stray light is extracted from the optical path by the light absorption layer, which removes the problematic light components before they can cause crosstalk between adjacent laser elements in the compact array.

Inventive Principle:
Principle #2Taking out (Extraction)

2Volume of moving object

If surface emitting laser elements are arranged in an array to save space, then device compactness is improved, but dark line formation between elements increases

Engineering Contradiction:
Improvedevice compactnessVSAvoiddark line formation
Core Design Contradiction:
Volume of moving objectVSIllumination intensity

Solution Approach 1:

The light absorption layer acts as a mediator that manages light distribution in the regions between laser elements. By controlling light absorption and reflection, it prevents the formation of dark lines while maintaining the compact array structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If surface emitting laser elements are used instead of LEDs, then light emission capability is improved, but heat generation increases

Engineering Contradiction:
Improvelight emission capabilityVSAvoidheat generation
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The light absorption layer, which absorbs stray light that would otherwise cause crosstalk, also absorbs excess heat energy. This converts the harmful stray light into beneficial heat dissipation, simultaneously addressing both crosstalk reduction and thermal management.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Object-generated harmful factors

If a light absorption layer is added to reduce crosstalk, then crosstalk reduction is improved, but device complexity increases

Engineering Contradiction:
Improvecrosstalk reductionVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The light absorption layer performs multiple functions simultaneously: it reduces crosstalk between laser elements, prevents dark line formation, and aids in heat dissipation. This multi-functionality justifies the added component by delivering multiple benefits from a single structural addition.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 crosstalk and dark line formation, achieving high contrast and uniform lighting while providing effective heat dissipation for reliable and long-lasting operation.

Implementation Method 1

a light absorption layer 17 formed on each of the light-emitting elements 12A and having an opening (light passage part) AP

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a light reflection film 19 formed on the light absorption layer 17

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a wavelength converter 13 provided on the light-emitting elements 12A and including a plurality of wavelength conversion plates 13A

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Implementation Method 4

a bonding metal layer 18 formed on the light reflection film 19

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3247008B1Surface emitting laser device
Publication Date: 2020.03.25 STANLEY ELECTRIC CO LTD
  • EP3247008B1 patent drawingFigure 1A~1B
  • EP3247008B1 patent drawingFigure 2A~2B
  • EP3247008B1 patent drawingFigure 3

AI summary

Provided is a surface emitting laser device (10) including a plurality of surface emitting laser elements (12A) and capable of significantly reducing the crosstalk of light and the formation of a dark line. The surface emitting laser device includes: a mounting substrate (11); a surface emitting laser array (12) including a plurality of surface emitting laser elements (12A) arranged side by side on the mounting substrate; a plurality of light absorption layers (17) formed on the plurality of surface emitting laser elements, respectively, and each including an opening (AP); and a plurality of wavelength conversion plates (13A) formed on the plurality of light absorption layers, respectively, and each including a fluorescent plate (PL) and a light reflection film (RF) covering a side surface of the fluorescent plate. The absorption layer (17) may include an antireflection layer (17A) at an interface with the surface emitting laser element.