Fiber Laser Beam Adjustment via Refractive Index Perturbation

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Solution Overview

Problem

Current fiber-coupled laser systems require complex and costly mechanisms to adjust beam characteristics, often relying on free-space optics that increase complexity, cost, and reduce reliability, failing to provide optimal performance for various materials processing tasks.

Innovation Solution

The system employs a method to adjust optical beam characteristics within the fiber itself by perturbing the fiber's refractive index profile and core dimensions, allowing for variable beam characteristics without the need for free-space optics, using techniques like bending, acousto-optic excitation, or thermal perturbation to modify beam parameters such as spot size, divergence, and intensity distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If free-space optics or complex add-on mechanisms are used to vary beam characteristics, then beam adjustability is improved, but device complexity and cost increase significantly

Engineering Contradiction:

Improvebeam characteristics adjustabilityVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the beam characteristic adjustment function from external free-space optics and relocates it directly into the fiber optic system. By modifying the fiber's refractive index profile through doping or structural changes, the system achieves beam adjustment capabilities that were previously only available through complex external mechanisms, thereby reducing overall system complexity while maintaining adaptability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the beam delivery function and beam characteristic adjustment function into a single integrated fiber optic system. Instead of using separate components for beam delivery and beam shaping, the invention combines these functions by incorporating adjustable refractive index profiles within the fiber itself, eliminating the need for additional free-space optics and reducing system complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If free-space optics are used to adjust beam characteristics, then beam versatility is improved, but reliability decreases due to additional components

Engineering Contradiction:

Improvebeam characteristics variabilityVSAvoidsystem reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent removes unreliable free-space optical components from the beam adjustment system and extracts the adjustment functionality directly into the fiber optic medium. By using integrated refractive index profiling within the fiber, the system achieves beam characteristic variability without the reliability penalties associated with additional external components.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If conventional laser systems with fixed beam characteristics are used, then device simplicity is maintained, but processing performance is compromised for different materials

Engineering Contradiction:

Improvesystem simplicityVSAvoidprocessing performance

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent introduces dynamic adjustability to the fiber optic system by enabling variable refractive index profiles through different doping concentrations or structural configurations. This allows the beam characteristics to be dynamically adjusted for different processing tasks while maintaining the inherent simplicity of the fiber optic delivery system, thereby improving processing performance without sacrificing device simplicity.

Inventive Principle:

Principle #15Dynamics

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 approach enables flexible and efficient adjustment of beam characteristics within the fiber, reducing costs and complexity while maintaining performance, allowing for optimized processing of different materials without the need for additional optics, thereby enhancing reliability and versatility.

Implementation Method 1

directing the provided optical beam to a target location on the material to melt and/or vaporize the material

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

directing the provided optical beam to a target location on the material to melt and/or vaporize the material

Methodology Applied

Scientific EffectAbsorption of optical energy: Absorption (EM radiation)

Implementation Method 3

providing an assist gas to the target location to assist in removal of debris from the material

Methodology Applied

Scientific EffectAblation: Ablation

Data Source

PatentUS10663742B2Method and system for cutting a material using a laser having adjustable beam characteristics

Publication Date: 2020.05.26 NLIGHT INC

AI summary

Disclosed herein are methods, apparatus, and systems for perturbing a laser beam propagating within a first length of fiber to adjust one or more beam characteristics of the laser beam in the first length of fiber or a second length of fiber or a combination thereof, coupling the perturbed laser beam into a second length of fiber and maintaining at least a portion of one or more adjusted beam characteristics within a second length of fiber having.