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Passive alignment stability and auto-alignment of multipass amplifiers based on Fourier transforms.
Applied Optics
|May 3, 2019
Summary
Fourier-based multipass amplifiers show improved tilt stability with a novel auto-alignment system. This advancement enhances their suitability for high-energy and high-power applications.
Area of Science:
- Optics and Photonics
- Laser Technology
- Beam Stability
Background:
- Fourier-based multipass amplifiers utilize Fourier transforms for beam transport between passes.
- Component misalignments (tilts) can significantly impact amplifier stability and performance.
- Existing amplifiers may face limitations in high-energy and high-power applications due to stability issues.
Purpose of the Study:
- To investigate the stability of Fourier-based multipass amplifiers to optical component tilts.
- To develop and validate a method for quantifying sensitivity to tilts.
- To propose and test an auto-alignment system for enhancing tilt stability.
Main Methods:
- Elaboration of a quantitative method based on small-signal gain to assess tilt sensitivity.
- Experimental comparison of the developed method with actual measurements.
- Implementation and testing of a simple auto-alignment system.
Main Results:
- A method to quantify tilt sensitivity in Fourier-based multipass amplifiers was successfully developed and validated against measurements.
- The proposed auto-alignment system demonstrated a significant improvement in tilt stability, exceeding an order of magnitude.
- The study confirms the robustness of Fourier-based amplifiers to tilts, aperture variations, and thermal lensing.
Conclusions:
- Fourier-based multipass amplifiers exhibit promising stability characteristics for demanding applications.
- The developed auto-alignment system offers a practical solution for enhancing tilt stability.
- These findings qualify Fourier-based amplifiers for deployment in high-energy and high-power laser systems.
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