Airtight Carbon Nanotube Saturable Absorber for Fiber Laser Durability

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Solution Overview

Problem

The durability of saturable absorbers in fiber laser devices is insufficient due to oxidation, which affects the longevity and performance of the devices.

Innovation Solution

Creating an airtight environment around the saturable absorber using a housing made of materials like zirconia, sealing with materials such as epoxy adhesive or solder, and filling with inert gases or liquids to prevent oxidation, while using carbon nanotubes dispersed in resin materials for enhanced durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the saturable absorber is exposed to air environment, then the device structure is simple, but the carbon nanotubes deteriorate due to oxidation reducing durability

Engineering Contradiction:
Improvedurability of saturable absorberVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the inert atmosphere principle by sealing the saturable absorber containing carbon nanotubes in an airtight housing filled with inert gas (such as nitrogen or rare gases). This prevents oxidation of the carbon nanotubes by isolating them from oxygen in the air, thereby enhancing durability and reliability of the saturable absorber without requiring complex protective measures

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The patent employs a housing structure with sealing elements (such as O-rings or sealing films) to create an airtight environment around the saturable absorber. This flexible sealing approach effectively isolates the carbon nanotubes from oxidative environment while maintaining a relatively simple overall device structure

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If sealing materials are used to create airtight space, then oxidation protection is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveoxidation protectionVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses sealing materials such as epoxy adhesive, solder, or brazing material to create an airtight housing filled with inert gas. This approach provides effective oxidation protection while maintaining ease of manufacture through straightforward sealing processes and commonly available materials

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The sealing material acts as an intermediary between the saturable absorber and the external environment, creating a barrier that prevents oxidation while allowing for simple manufacturing processes through standard sealing techniques

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

The solution significantly extends the life and durability of the saturable absorber, maintaining performance for an extended period by preventing oxidation and enhancing thermal diffusion.

Implementation Method 1

a fiber structure, a pulse laser device, and a supercontinuum light source capable of enhancing durability... deterioration of the carbon nanotubes in the saturable absorber attributable to oxidation can be suppressed

Methodology Applied
Scientific EffectSaturable absorption: Absorption (EM radiation)

Implementation Method 2

enhancing thermal diffusion... maintaining performance for an extended period

Methodology Applied
Scientific EffectThermal diffusion: Conduction (thermal)

Data Source

PatentEP3872544B1Fiber structure, pulse laser device, and supercontinuum light source
Publication Date: 2024.07.10 HAMAMATSU PHOTONICS KK
  • EP3872544B1 patent drawingFigure 1
  • EP3872544B1 patent drawingFigure 2
  • EP3872544B1 patent drawingFigure 3

AI summary

A fiber structure includes first and second optical fibers disposed such that end portions thereof butt, a sheet-shaped saturable absorber including a carbon nanotube and disposed between the end portion of the first optical fiber and the end portion of the second optical fiber, and a housing internally accommodating the end portion of the first optical fiber and the end portion of the second optical fiber. A space in the housing including the saturable absorber is airtight.