Colliding Gas Jets Form Plasma Waveguides
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for maintaining high laser pulse intensity over long distances in plasma waveguides face challenges, particularly in creating effective plasma channels beyond 10 cm due to difficulties in diagnosing and sustaining plasma within capillary discharge structures, which are prone to damage and limited by the need for precise alignment and high laser energy.
Innovation Solution
A method using colliding gas jets to form a wall-free plasma waveguide with a predetermined density profile, where gas jets with equal angular separation collide to create a hollow channel with a central density minimum, which is then ionized to guide laser pulses, allowing for extended plasma channel formation without the need for additional optical components and enabling precise control over plasma parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capillary discharge structures are used to create plasma waveguides, then plasma channel formation is achieved, but the structures are prone to damage and limited by precise alignment requirements and high laser energy needs
Solution Approach 1:
The patent removes the capillary discharge structure entirely, extracting the harmful wall component from the plasma channel formation process. Instead of using a physical capillary tube that requires precise alignment and high laser energy, the invention uses colliding gas jets to create a wall-free plasma channel, eliminating the source of damage and alignment complexity
Solution Approach 2:
The patent employs gas jet flows (pneumatic system) to create the plasma channel. Multiple gas jets collide to form a hollow channel structure filled with plasma, replacing the mechanical capillary discharge approach. This pneumatic method provides better control over plasma formation without the alignment and energy constraints of traditional capillary systems
2Length of moving object
If conventional optical components are used to focus laser beams, then laser focusing is achieved, but the components must be placed far from the laser focus, limiting the interaction distance to the Rayleigh range
Solution Approach 1:
The patent introduces plasma as an intermediary medium between the laser source and the interaction region. The plasma channel acts as a waveguide that guides the laser beam over extended distances beyond the Rayleigh range. The plasma density profile (with minimum at center and maximum at walls) provides the necessary refractive index gradient to maintain laser focus without requiring conventional optical components at long distances
Solution Approach 2:
The patent changes the physical state and density parameters of the medium through which the laser propagates. By creating a plasma channel with specific density distribution (minimum at center, maximum at walls), the refractive index is modified to enable long-distance guiding. This parameter change allows the laser to maintain focus over distances exceeding the Rayleigh range
3Ease of operation
If wall-free channels based on axicon-focused lasers are used, then laser guiding is achieved, but high laser energy and precise co-linear alignment are required
Solution Approach 1:
The patent replaces the optical-mechanical alignment system (axicon and co-linear alignment) with a gas-dynamic system. Multiple gas jets are directed to collide and form the plasma channel, eliminating the need for precise optical alignment. The gas jet arrangement naturally creates the desired plasma density profile without requiring complex optical component alignment
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 the creation of stable, tunable plasma channels that can guide laser pulses over longer distances, simplifying alignment and diagnostics, and is compatible with standard diagnostic techniques, offering scalability and high repetition rates without the limitations of capillary-based methods.
Implementation Method 1
Hot gas near the axis expands radially, forming a hollow density channel suitable for guiding
Implementation Method 2
The gas flows collide and form a gas channel from the neutral gas
Implementation Method 3
Ionization of the gas in the center produces a plasma channel that can guide a laser pulse
Implementation Method 4
The plasma channel acts as a waveguide for the laser pulse combating diffraction
Data Source
AI summary
A plurality of gas jet nozzles having equal angular separation around a central axis eject gas flows towards the central axis. The gas flows collide and form a gas channel from the neutral gas, the gas channel having a gas density depression at the center of the intersecting gas flow, where the gas density depression is surrounded by a higher density gaseous wall along the central axis. Ionization of the gas in the center produces a plasma channel that can guide a laser pulse fired into the gas along the central axis. The geometric arrangement of the gas jets and/or the backing pressure of the gas flows are configured to produce a gas channel having a predetermined density profile such that the ionized gas forms a plasma channel laser guiding structure configured to guide a laser pulse having predetermined spatial parameters.