Diode-Pumped Solid State Molecular Gas Laser
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Solution Overview
Problem
Existing mid-infrared vibrational-rotational transition lasers face inefficiencies due to reliance on chemical or electrical discharge excitation, which leads to issues like toxic exhaust handling, limited spectral diversity, and inability to operate in high power/high energy pulsed modes, as well as reduced performance from narrow pump line widths and impractical chemical laser systems.
Innovation Solution
Implementing a laser diode excited solid state system with multiple principle and excited state overtone pumps, allowing for direct excitation of higher vibrational levels, a closed cycle gas operation, and efficient energy storage and delivery, thereby overcoming the limitations of prior art by leveraging synergies in Thulium or Erbium doped solid state lasers and suitable gas components for broad spectral output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If chemical or electrical discharge excitation is used to energize mid-infrared vibrational-rotational transition lasers, then high power/high energy capability is achieved, but toxic exhaust handling and reactive precursor requirements become problematic
Solution Approach 1:
The patent replaces chemical and electrical discharge excitation systems with optical pumping using laser diodes. This substitution eliminates the need for reactive chemical precursors and toxic exhaust handling while maintaining the ability to generate high power mid-infrared laser output through optical energy transfer to the molecular gas medium.
Solution Approach 2:
The patent changes the excitation parameter from chemical/electrical to optical, using laser diode pumped solid state sources with nanometer scale spectral bandwidths to pump molecular transitions. This parameter change enables clean energy input without the harmful byproducts of chemical reactions or electrical discharges.
2Ease of operation
If electrical discharge pumped Carbon Monoxide lasers are used, then laser operation is achieved, but emission wavelengths are limited to greater than approximately 5.6 μm which is above the atmospheric transmission window
Solution Approach 1:
The patent uses laser diode pumped solid state sources that can be tuned to match different molecular overtone transitions, enabling operation at multiple wavelengths including those within the 4.6 μm to 5.4 μm atmospheric transmission window. This provides universal access to different spectral regions while maintaining ease of operation.
Solution Approach 2:
The patent employs dynamic spectral selection by matching laser diode wavelengths to specific molecular overtone transitions. The system can dynamically adjust which vibrational-rotational transitions are pumped, enabling access to different atmospheric windows and spectral regions as needed.
3Use of energy by moving object
If resonant transfer approach with alkali vapor and hetero-nuclear molecular gas is used, then improved efficiency is achieved, but dissociated halogen components scavenge alkali atomic vapor components eroding donor/acceptor gas mix balance
Solution Approach 1:
The patent extracts and eliminates the problematic resonant transfer step involving alkali vapor and hetero-nuclear molecular gas. By using direct laser diode pumping of molecular overtone transitions, the system removes the intermediate alkali vapor stage that causes dissociated halogen components to scavenge alkali atomic vapor, thereby maintaining gas mix balance and improving reliability.
4Use of energy by moving object
If conventional semiconductor laser diode pump sources with nanometer scale spectral bandwidths are used, then improved efficiency is achieved, but spectral diversity is reduced
Solution Approach 1:
The patent segments the pumping process by using multiple laser diode sources, each tuned to a specific overtone transition. This segmentation allows efficient pumping of different vibrational levels while maintaining spectral diversity, as each diode operates at its optimal wavelength matched to a specific molecular transition.
Solution Approach 2:
The patent applies partial pumping by selectively exciting specific overtone transitions rather than attempting to pump all transitions simultaneously. This partial action approach maintains efficiency by matching laser diode bandwidths to specific transitions while still achieving broad spectral coverage through the combination of multiple pumped transitions.
5Ease of operation
If alkali vapor generation is required for resonant transfer laser operation, then laser operation is achieved, but system complexity increases due to temperature conditioning requirements
Solution Approach 1:
The patent replaces the complex temperature conditioning system required for alkali vapor generation with a simpler direct optical pumping system. Laser diode pumped solid state sources can operate at room temperature or with minimal thermal management, eliminating the need for heated vaporization chambers and complex temperature control systems.
6Ease of operation
If chemical or electrical discharge pumped systems are used, then laser operation is achieved, but closed cycle operation is not possible due to precursor consumption and product handling requirements
Solution Approach 1:
The patent replaces chemical and electrical discharge pumping with optical pumping, enabling closed cycle operation. The molecular gas medium can be cyclically pumped between vibrational states without chemical consumption, as the laser diode energy input causes no permanent chemical changes, allowing the gas to be recovered and reused indefinitely.
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 efficient, multispectral operation within critical atmospheric windows, achieving high power/high energy capabilities, spectral agility, and reduced thermal shedding, while eliminating the need for precursor and product gas handling, thus enhancing system performance and flexibility.
Implementation Method 1
laser diode excited solid state system
Implementation Method 2
conventional semiconductor laser diode pump sources
Implementation Method 3
Mid-infrared vibrational-rotational transition lasers
Implementation Method 4
resonant transfer approach
Implementation Method 5
lasing medium energy storage capability
Data Source
AI summary
The closed cycle solid state optically pumped gas hybrid (chemical recovery) system utilizes a laser diode excited solid state, fiber or bulk, laser as a pump for a molecular gas, or gas mix, medium. The existence of efficient high power laser diode excited solid state fiber or bulk lasers, output spectrally matched to suitable principle and excited level 1st and 2nd overtones of relevant gases, is the enabling system technology. The utilization of such in combination with suitable gases introduces a range of viable, in principle sourcing on laser diodes and thus effectively laser diode pumped, gas laser systems with access to the approximately 4.5 μm to approximately 5.4 μm spectral region. Continuous wave or pulsed operation, with significant energy capability courtesy of solid state storage, is admitted.