Spatiotemporal rogue events in optical multiple filamentation.

Area of Science:

• Nonlinear Optics
• Plasma Physics
• Laser-Matter Interactions

Background:

• Optical filaments are generated through intense laser-matter interactions in nonlinear media.
• Understanding the statistical properties of these filaments, especially extreme events, is crucial for controlling laser propagation.

Purpose of the Study:

• To experimentally investigate the transient bright spots in optical filaments formed in xenon.
• To analyze the statistical distributions of fluence profiles and identify the origins of extreme events.

Main Methods:

• High-speed optical cameras recorded fluence profiles at kilohertz repetition rates.
• Statistical analysis was performed on the recorded data to characterize fluence distributions.
• The role of multiphoton absorption, plasma thermalization, and filament mergers was examined.

Main Results:

• A thresholdlike transition from single to multiple filamentation was observed.
• Heavy-tailed fluence distributions, with extreme events exceeding significant wave height by over 10x, were identified.
• Extreme events were found to be spatially and temporally isolated.

Conclusions:

• Macroscopic refractive index variations due to plasma dynamics drive the observed heavy-tail statistics.
• Microscopic filament mergers are critical in the statistical behavior of rogue waves in this system.
• The findings provide insights into extreme event formation in nonlinear light propagation.