Femtosecond nonlinear fiber optics in the ionization regime

Area of Science:

• Nonlinear optics
• Laser-matter interaction
• Photonics

Background:

• Photonic crystal fibers (PCFs) offer unique light-guiding properties.
• Kagome-style PCFs provide low anomalous dispersion and low loss.
• Optically induced ionization is a key phenomenon in high-intensity laser-matter interactions.

Purpose of the Study:

• To investigate nonlinear fiber optics in the regime of optically induced ionization.
• To explore the potential of gas-filled kagome-style PCFs for studying ionization.
• To characterize the generation of blueshifted pulses and free-electron densities.

Main Methods:

• Utilizing a gas-filled kagome-style photonic crystal fiber.
• Launching 65 fs, few-microjoule pulses into the fiber.
• Observing pulse self-compression and blueshifted emission.
• Performing numerical simulations to confirm experimental findings.

Main Results:

• Observed sequences of blueshifted pulses due to high-order soliton self-compression.
• Achieved peak intensities of approximately 10(14) W/cm(2).
• Estimated free-electron densities of around 10(17) cm(-3) over centimeter-scale lengths.

Conclusions:

• Gas-filled kagome-style PCFs are suitable for studying nonlinear fiber optics and optically induced ionization.
• High-order soliton self-compression leads to significant blueshifted pulse generation.
• The experimental setup achieved high free-electron densities, relevant for various laser-matter interaction studies.