Fiber Laser Array Phase Coupling for Turbulence Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fiber laser arrangements face challenges in maintaining beam quality due to atmospheric turbulence, which limits their practical application, especially in high-energy settings.
Innovation Solution
A phase-coupled fiber laser arrangement with neodymium, holmium, or erbium glass fiber lasers, pumped by diodes, uses a fiber splitter to distribute pump energy into multiple branches with optical phase shifters and phase amplifiers, controlled by electronic devices to compensate for turbulence effects, achieving optimal focusing through wavefront sensors and phase conjugation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If adaptive mirrors are used to compensate for atmospheric turbulence, then beam quality is improved, but the control bandwidth is limited by the mechanical properties of the mirrors
Solution Approach 1:
The patent replaces the mechanical adaptive mirror system with an all-optical phase conjugation system using fiber lasers. Instead of mechanically deforming a mirror surface to correct wavefront distortions, the invention uses optical phase shifter elements in multiple fiber branches to create a phase-conjugated replica of the distorted wavefront, eliminating mechanical limitations and achieving higher control bandwidth.
Solution Approach 2:
The patent divides the laser system into multiple independent fiber laser branches (at least two branches), each with its own phase shifter elements. This segmentation allows parallel processing of wavefront correction across different spatial modes, increasing the overall control bandwidth and enabling more sophisticated turbulence compensation compared to a single mirror system.
2Power
If laser power is increased in high-energy laser arrangements, then energy output is improved, but atmospheric turbulence disturbances worsen and limit practical application
Solution Approach 1:
The patent converts the harmful effect of atmospheric turbulence into a useful measurement signal. By detecting the turbulence-induced wavefront distortions and generating a phase-conjugated replica, the system uses the turbulence pattern itself to create corrective action, transforming the harmful disturbance into the basis for compensation and enabling high-power laser transmission through turbulent atmospheres.
3Power
If multiple fiber laser branches are used to increase overall power, then energy output is improved, but maintaining optimal phase coupling becomes more complex
Solution Approach 1:
The patent implements a feedback control system where wavefront sensors detect the actual wavefront distortions in each fiber branch, and this measurement information is used to adjust the phase shifter elements accordingly. The feedback loop continuously monitors and corrects phase differences, automatically maintaining optimal phase coupling across multiple branches without requiring complex manual calibration or control mechanisms.
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 solution enhances beam quality by focusing laser radiation to a small spot size, allowing scalable increase in laser power without quality loss due to turbulence, enabling effective long-distance communication and countermeasure applications.
Implementation Method 1
at least one fiber laser amplifier (12) with a laser radiation wavelength of 1.06 µm, which derives its pump energy from a common fiber laser master oscillator (13)
Implementation Method 2
Each fiber laser amplifier (12.1 - 12.4) is assigned an electro-optical phase shifter (14.1 to 14.4)
Implementation Method 3
a beam splitter (32) assigned to the wave front sensor (22) and used to direct the light scattered back from the target point (24) on the propagation path to the fiber laser array (10) to the wavefront sensor (22), which measures the phase front of the light
Implementation Method 4
an optical fiber cable (11) in which a number - in the exemplary embodiment four - fiber laser amplifiers (12.1 - 12.4) are coupled in series optically
Data Source
Figure 1
AI summary
The invention relates to a high-power fiber laser arrangement (10) consisting of several continuously operating coherent single-fiber lasers (12.1 - 12.n) to which the pump energy generated by a common master oscillator (12) operating in longitudinal mode can be supplied in a branched distribution via a fiber splitter (15), wherein each single-fiber laser (12.1 - 12.n) is assigned an integrated electro-optic phase shifter (14.1 - 14.n) which can be controlled by control electronics (16) such that atmospheric turbulence effects on the propagation path of the laser radiation to a target (24) are compensated by suitable shifts of the optical phases in individual phases (12.1 - 12.n) of the fiber laser arrangement (10) in order to obtain optimal focusing of the entire laser radiation on the distant target (24).