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Full-Text Articles in Engineering
Filaments And Their Application To Air Lasing, Spectroscopy, And Guided Discharge, Ali Rastegari
Filaments And Their Application To Air Lasing, Spectroscopy, And Guided Discharge, Ali Rastegari
Optical Science and Engineering ETDs
Laser filamentation is a fascinating phenomenon that occurs when an intense laser beam travels through transparent materials, in particular air. At sufficiently high power (TW in the near IR, GW in the UV), instead of spreading out like a regular laser beam, something remarkable happens: the laser beam becomes tightly focused, creating a thin and intense column of light called a laser filament. Laser filamentation is characterized by two main properties: (I) a high-intensity core that remains narrow over long distances beyond the Rayleigh range and (II) a low-density plasma channel within the core. In recent years, laser filamentation has …
Ultrashort Pulse Laser Filamentation Electrical And Optical Diagnostic Comparison, James E. Wymer
Ultrashort Pulse Laser Filamentation Electrical And Optical Diagnostic Comparison, James E. Wymer
Optical Science and Engineering ETDs
Results presented here examine the effect of changing gas pressure on the radio frequency (RF) emissions of an ultrashort pulse laser filament plasma and how those emissions vary longitudinally in the laser focal region. We use a WR284 rectangular waveguide with a 1.5 cm hole that allows the beam through. A 3.2 GHz microwave signal is emitted in the waveguide, and signals are received through a waveguide-to-coax antenna connected to an HP8470B Schottky diode. By enabling and disabling the 3.2 GHz signal, we measure both the self-emitted RF from a USPL filament and subsequently the degree of attenuation a filament …