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Polarization separator created by a filament in air
Yanping Chen1, Claude Marceau, Francis Théberge
1Centre d'Optique, Photonique et Laser (COPL) and Département de Physique, de Génie Physique et d'Optique, Université Laval, Québec, Québec G1V 0A6, Canada. yanping.chen.1@ulaval.ca
Optics Letters
|November 28, 2008
Summary
A femtosecond laser filament acts as a polarization separator, guiding parallel-polarized probe pulses and diffracting orthogonal components. This technique achieves high extinction ratios for femtosecond laser applications.
Area of Science:
- Nonlinear Optics
- Ultrafast Laser Physics
- Plasma Photonics
Background:
- Femtosecond laser filaments are generated through the self-focusing of intense laser pulses in a medium.
- Controlling laser pulse polarization is crucial for various optical applications.
Purpose of the Study:
- To investigate the potential of femtosecond laser filaments as polarization separators.
- To analyze the spatial separation of orthogonally polarized probe pulses within a filament.
Main Methods:
- Utilizing a femtosecond pump laser to induce a filament in a medium.
- Launching a copropagating femtosecond probe pulse with controlled polarization relative to the pump.
- Analyzing the spatial distribution of the probe pulse components after filament propagation.
Main Results:
- The femtosecond laser filament effectively separates the probe pulse's polarization components.
- Probe polarization parallel to the pump is guided along the filament axis.
- Probe polarization orthogonal to the pump is diffracted into an outer ring by the plasma.
Conclusions:
- Femtosecond laser filaments can function as efficient polarization separators.
- This phenomenon offers a novel method for manipulating ultrafast laser pulse polarization.
- The demonstrated technique achieves an extinction ratio exceeding 1:20 for on-axis probe pulses.
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