Underwater Laser-Guided Discharge via Optical Filaments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for generating and guiding electrical discharges in water lack the precision and conductivity needed for efficient underwater applications, as they rely on nonlinear self-focusing and ionization-induced defocusing, which are not easily controllable and reproducible.
Innovation Solution
A method using high-powered laser pulses focused through lenses to create optical filaments in water, generating ionized channels with higher conductivity than the surrounding water, allowing for controlled and reproducible guidance of electrical discharges by configuring the laser power and lens parameters to form filaments at desired locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nonlinear self-focusing and ionization-induced defocusing are used to generate optical filaments, then electrical discharges can be guided through water, but the process is not easily controllable and reproducible
Solution Approach 1:
The patent applies preliminary action by using a laser pulse to pre-ionize water molecules and create an optical filament before the electrical discharge occurs. The laser pulse is fired first to generate the conductive path, which then guides the subsequent electrical discharge. This sequential approach ensures the discharge path is established in advance, improving controllability and reproducibility.
Solution Approach 2:
The patent uses an optical filament as an intermediary medium between the laser source and the electrical discharge. The optical filament, created by laser-induced ionization, serves as a conductive bridge that guides the electrical discharge through the water. This intermediary structure simplifies the overall system by providing a clear, controllable path for discharge guidance.
2Reliability
If high-powered laser pulses are used to create optical filaments, then conductivity of the discharge path is improved, but energy consumption increases
Solution Approach 1:
The patent employs periodic action by using pulsed laser beams rather than continuous laser illumination. The laser is activated in discrete pulses just before and during the electrical discharge, creating the optical filament only when needed. This periodic operation significantly reduces overall energy consumption while maintaining the high conductivity required for effective discharge guidance.
Solution Approach 2:
The patent applies the skipping principle by using ultra-short duration laser pulses (on the order of nanoseconds or less) to create the optical filament. The laser pulse is applied only for the brief moment needed to ionize the water and form the conductive path, rather than continuously. This rushing through the ionization process quickly minimizes energy input while achieving the required conductivity.
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 precise and efficient guidance of electrical discharges through underwater ionized channels, offering improved conductivity and controllability, suitable for various applications including micromachining and pulsed-power switching.
Implementation Method 1
Both air and water are subject to the Kerr effect, wherein the index of refraction of the optical medium increases upon the application of an electric field associated with an electromagnetic wave such as a laser beam. The result of the Kerr effect acting on a laser beam with a centrally peaked intensity profile is whole-beam nonlinear self-focusing (NSF).
Implementation Method 2
Both air and water also exhibit photoionization, in which the medium within a high-intensity light source becomes ionized. Ionized molecules in an optical media decrease the index of refraction.
Implementation Method 3
At high light intensity, Kerr-induced self-focusing and ionization-induced defocusing can combine and offset to result in the formation of an optical filament and an associated extended volume of ionized air or water. An optical filament is a light beam which propagates at high intensity and small radius for long distances, beyond the divergence distance normally determined by diffraction.
Implementation Method 4
The ionized channel associated with an optical filament can serve as a path of relative high conductivity, sufficient to guide an electrical discharge through that optical medium.
Data Source
AI summary
Methods for producing a laser-guided underwater electrical discharge are provided. One or more electrodes defining a desired electrical discharge path are situated in a body of water and are attached to an external electrical power supply. A high-powered, intense laser beam is fired through one or more focusing lenses into the water. The laser beam forms an optical filament in the water, which in turn forms an ionized channel having a much greater conductivity than the surrounding water. An external power supply drives an electrical discharge along the path of the ionized channel due to its greater conductivity.