Tm-Doped Solid State Pump for CO2 Laser Tunability

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Solution Overview

Problem

Existing high power, infra-red, optically pumped CO2 lasers face inefficiencies due to the use of chemical laser pumps like Hydrogen Bromide (HBr), which require handling of exhaust products and precursor fuels, and have limited spectral overlap with CO2 transitions, leading to suboptimal performance at low to moderate pressures.

Innovation Solution

A laser diode pumped Thulium (Tm) doped solid state system directly optically pumps the 00 0→20 0 and/or 00 0→12 0 transition bands of CO2, allowing for continuous tunability and efficient operation from ~9µm to ~11.5µm, avoiding the limitations of chemical laser pumps and enabling high-pressure operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If HBr chemical laser pump is used, then pump power can be achieved, but spectral overlap with CO2 transitions is limited and handling of exhaust products and precursor fuels is required

Engineering Contradiction:
Improvepump powerVSAvoidsystem complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the chemical reaction components (HBr pump, exhaust products, precursor fuels) from the laser system, replacing them with a solid-state laser pump that uses only CO2 isotopologue gas mixes, thereby simplifying the system while maintaining pump power

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the pump source from a chemical laser (HBr) to a solid-state laser with可调 wavelength capability, allowing optimization of spectral overlap with CO2 transitions and eliminating the need for chemical handling

Inventive Principle:
Principle #35Parameter changes

2Reliability

If HBr laser pump is used, then pumping can be achieved, but spectral matching efficiency is poor due to limited bandwidth and line structure

Engineering Contradiction:
Improvepumping efficiencyVSAvoidenergy efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs a solid-state laser pump with continuously可调 wavelength capability, enabling precise matching to CO2 absorption lines and maximizing energy transfer efficiency, whereas HBr has fixed line structure with limited tunability

Inventive Principle:
Principle #35Parameter changes

3Power

If chemical laser pump is used, then pumping capability is achieved, but dissociation occurs and catalysts are required

Engineering Contradiction:
Improvepump capabilityVSAvoidoperational simplicity
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The patent removes the chemical reaction chain entirely by using a solid-state laser pump instead of HBr chemical laser, eliminating dissociation products and the need for catalysts, thereby greatly simplifying operation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the chemical mechanism (HBr dissociation and reaction) with a physical/optical mechanism (solid-state laser emission), eliminating the need for chemical handling and catalysts

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 achieves high efficiency and continuous tunability, reducing dissociation and the need for catalysts, and allows for the use of multi-CO2 isotopologue gas mixes, enhancing system performance and extending operational pressure ranges.

Implementation Method 1

A laser diode pumped Thulium (Tm) doped solid state system directly optically pumps the 00 0→20 0 and/or 00 0→12 0 transition bands of CO2

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

directly optically pumps the 00 0→20 0 and/or 00 0→12 0 transition bands of CO2

Methodology Applied
Scientific EffectOptical pumping:

Implementation Method 3

The Tm solid state system is spectrally ideally matched to the 00 0→20 0 and/or 00 0→12 0 transition bands of CO2

Methodology Applied
Scientific EffectVibrational energy transfer:

Data Source

PatentEP2727201B1A co2 laser
Publication Date: 2019.04.17 CAMPBELL CO
  • EP2727201B1 patent drawingFigure 1~2E
  • EP2727201B1 patent drawingFigure 3

AI summary

Efficient laser diode excited Thulium (Tm) doped solid state systems, directly matched to a combination band pump transition of Carbon Dioxide (CO2), have matured to the point that utilization of such in combination with CO2 admits effectively a laser diode pumped CO2 laser. The laser diode excited Tm solid state pump permits Continuous Wave or pulsed energy application. Appropriate optical pumping admits catalyzer free near indefinite gas lifetime courtesy of the absence of significant discharge driven dissociation and contamination. As a direct consequence of the preceding arbitrary multi isotopologue CO2, symmetric and asymmetric, gas mixes may be utilized without significant degradation or departure from initial mix specifications. This would admit, at raised pressure, a system continuously tunable from ~9μm to ~1 1.5μm, or sub picosecond amplification. This methodology offers advantages in regards scalability, pulse energy and power over alternative non linear conversion techniques in access to this spectral region.