Diode Laser Module Stepped Platform Beam Combination

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Solution Overview

Problem

Existing multi-emitter laser modules face challenges in achieving high optical power and brightness due to beam divergence and interference issues, requiring improved architectures and housings to effectively combine radiation from multiple laser sources into a single optical fiber.

Innovation Solution

A laser module design featuring stepped platforms for aligning laser sources, reflectors for redirecting radiation, and an optical combiner to combine beams into a single output, with fast and slow axis collimators and a volume Bragg grating for stabilization, allowing for efficient coupling into an optical fiber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple laser sources are assembled in a module to increase optical power, then the optical output power is improved, but beam divergence and interference issues worsen

Engineering Contradiction:
Improveoptical output powerVSAvoidbeam divergence and interference
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The patent employs stepped platforms arranged in multiple levels (first and second plurality of platforms at different heights) to stack laser sources vertically in the z-dimension. This dimensional arrangement allows beams from multiple sources to be combined along the optical axis while maintaining spatial separation, thereby increasing optical power without proportionally increasing beam divergence and interference issues.

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

Solution Approach 2:

The patent introduces reflectors as intermediary components positioned between the laser sources and the optical combiner. These reflectors redirect beams from laser sources on stepped platforms into the optical combiner, enabling precise beam alignment and reducing direct interference between multiple laser sources while facilitating effective beam combination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If individual laser sources are aligned and combined using optical components, then the brightness and optical power are improved, but the device complexity increases

Engineering Contradiction:
ImprovebrightnessVSAvoidmodule architecture complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges multiple laser sources onto integrated stepped platforms where each platform hosts both laser sources and their corresponding reflectors. This consolidation reduces the number of separate mounting components and simplifies the overall module architecture while maintaining the capability to combine multiple beams effectively for increased brightness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stepped platforms serve multiple functions simultaneously: they provide mechanical support for laser sources, establish precise spatial positioning for beam alignment, and integrate reflector mounting surfaces. This multi-functionality reduces the number of separate components needed, thereby simplifying the device complexity while achieving high brightness through effective beam combination.

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

3Object-affected harmful factors

If laser sources are positioned at different distances from the optical combiner, then beam interference is minimized, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvebeam interferenceVSAvoidpositioning precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The stepped platforms are pre-designed with specific step heights that establish predetermined distances between laser sources on different levels and the optical combiner. This preliminary design of the platform structure provides built-in spatial separation that minimizes beam interference while reducing the need for high-precision adjustments during assembly, as the positioning is determined by the manufactured platform geometry rather than post-assembly alignment.

Inventive Principle:
Principle #10Preliminary action

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

The design enhances optical power and brightness by minimizing beam interference and divergence, enabling increased power coupling into optical fibers while maintaining a compact and cost-effective module architecture.

Implementation Method 1

a first plurality of reflectors, wherein one of the first plurality of reflectors is to receive radiation from the laser source located on the one of the first plurality of stepped platforms and to reflect radiation in a second direction

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

an optical combiner that combines the radiation of the first and second plurality of laser sources into a single beam

Methodology Applied
Scientific EffectOptical interference: Interference

Implementation Method 3

with a volume Bragg grating for stabilization

Methodology Applied
Scientific EffectBragg diffraction: Bragg Diffraction

Data Source

PatentEP3367520B1Arrangement of diode laser module
Publication Date: 2021.05.05 TRUMPF PHOTONICS INC
  • EP3367520B1 patent drawingFigure 1~2
  • EP3367520B1 patent drawingFigure 3~4
  • EP3367520B1 patent drawingFigure 5~6

AI summary

Disclosed is a laser module comprising: a housing having a platform (a - g, h - n); one or more laser sources (303) secured to the platform; optical components to direct radiation from the one or more lasers to an endcap (1505), the endcap being positionally secured to a structure in the platform; an optical fiber (1506) secured inside the housing to the endcap (1505); an epoxy coating applied to a cladding of the optical fiber (1506) inside the housing, wherein a refractive index of the coating is the same or greater than a refractive index of the cladding.