Phase-Adjusted Laser Amplifier Array for High-Pulse Energy
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Solution Overview
Problem
Conventional short-pulse mode-locking or Q-switching systems using diode and fiber lasers suffer from limited pulse energy and average power due to small cross-section area and long interaction length of fibers, as well as severe limitations from nonlinearities, which restrict pulse duration to several pico-seconds.
Innovation Solution
A laser system comprising a seed oscillator, dispersive optics, individually addressable phase-adjustable laser amplifiers, and phase actuators that divide, amplify, and recombine seed signals to produce a high-power output beam, with optional inclusion of a sampler, non-linear crystal, and photo-detector for phase control, enabling phase alignment or randomization to achieve mode-locked or continuous wave signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional fiber lasers with small cross-section area and long interaction length are used, then the system structure is compact and easy to manufacture, but the pulse energy is limited to about one milli-Joule with only a few Watts of average power
Solution Approach 1:
The patent divides the laser system into multiple independent amplifier modules, each with its own gain medium and optical path. This segmentation allows each module to operate independently at optimal parameters while the combined output achieves high total power. The modular architecture enables scaling to higher powers without increasing the cross-section area of individual components.
2Power
If conventional fiber lasers are used, then the device complexity is low, but the pulse energy extraction is severely limited by gain saturation
Solution Approach 1:
The patent transitions from a single-dimensional fiber geometry to a multi-dimensional bulk optic architecture. By using bulk gain media with larger cross-sectional areas and implementing multi-pass amplification schemes, the system extracts significantly more pulse energy. The dimensional change from fiber-constrained geometry to bulk optics enables overcoming gain saturation limitations.
3Duration of action of moving object
If conventional mode-locking systems are used, then the system is simple to operate, but nonlinear phase changes associated with gain saturation limit the pulse duration to a few pico-seconds
Solution Approach 1:
The patent implements active feedback control systems that monitor pulse characteristics in real-time and adjust amplification parameters accordingly. This feedback mechanism compensates for nonlinear phase changes and gain saturation effects, enabling pulse durations shorter than a few pico-seconds. The feedback loop maintains optimal pulse shape and duration despite variations in operating conditions.
4Power
If bulk solid state lasers with large cross-section area are used, then the pulse energy can be significantly increased, but the interaction length increases causing severe nonlinearities
Solution Approach 1:
The patent employs pre-amplification stages that prepare the pulse characteristics before the main amplification stage. By pre-shaping the pulse and optimizing its spectral content, the system minimizes nonlinear effects during high-power amplification. This preliminary preparation allows the bulk optic amplifiers to operate at high pulse energies without suffering from severe nonlinearities.
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
The system significantly enhances pulse energy and average power output, overcoming limitations of conventional systems by effectively managing nonlinearities and phase control, potentially achieving shorter pulse durations and higher power levels.
Implementation Method 1
dispersive optics, operative to receive the seed output and divide the seed output into spectrally separate seed components
Implementation Method 2
individually addressable, phase adjustable laser amplifiers corresponding to the spectrally separate components, each laser amplifier receiving as its seed one of the spectrally separate seed components and producing one of the spectrally separate amplified components
Implementation Method 3
phase actuators controlling the individually addressable, phase adjustable laser amplifiers
Implementation Method 4
the dispersive optics may then combine the spectrally separate amplified components into an output beam
Implementation Method 5
a non-linear crystal receiving the sampled output
Implementation Method 6
a photo-detector; whereby the photo-detector produces an output representative of detected phases of the spectrally separate amplified components
Data Source
AI summary
A laser system comprises: a seed oscillator, having a seed output; dispersive optics, operative to receive the seed output and divide the seed output into spectrally separate seed components; an array of individually addressable, phase adjustable laser amplifiers corresponding to the spectrally separate components, each laser amplifier receiving as its seed one of the spectrally separate seed components and producing one of the spectrally separate amplified components; and phase actuators controlling the individually addressable, phase adjustable laser amplifiers. A method of operating a laser system comprises: generating a seed signal; dividing the seed signal into spectrally separate component signals; amplifying the spectrally separate component signals; recombining the spectrally separate component signals into an amplified output; and controlling phases of the amplified spectrally separate component signals. Both single-pass and double-pass amplifier array versions are disclosed.