Long-distance transfer of microwaves in sliding-mode virtual plasma waveguides

Experimentally an effective channeling and transfer of the sliding mode of the 35.3 GHz (λ ≈ 8.5 mm) microwave signal along 60 m distance has been demonstrated in the low-density (ne ∼ 1012 cm−3) 10 cm diameter hollow plasma waveguide created by the 100 ns UV pulse of GARPUN KrF laser in the laboratory air. The mechanism of the transfer is the total internal reflection of the signal on the optically less dense walls of the waveguide. The theory of this sliding mode propagation in large-diameter (D � λ) plasma waveguides is developed, which is in good accordance with our experimental results

A New Insight into High-Aspect-Ratio Channel Drilling in Translucent Dielectrics with a KrF Laser for Waveguide Applications

A new insight into capillary channel formation with a high aspect ratio in the translucent matter by nanosecond UV laser pulses is discussed based on our experiments on KrF laser multi-pulse drilling of polymethyl methacrylate and K8 silica glass. The proposed mechanism includes self-consistent laser beam filamentation along a small UV light penetration depth caused by a local refraction index increase due to material densification by both UV and ablation pressure, followed by filamentation-assisted ablation. A similar mechanism was shown to be realized in highly transparent media, i.e., KU-1 glass with a multiphoton absorption switched on instead of linear absorption. Waveguide laser beam propagation in long capillary channels was considered for direct electron acceleration by high-power laser pulses and nonlinear compression of excimer laser pulses into the picosecond range

Explosion and Dynamic Transparency of Low-Density Structured Polymeric Targets Irradiated by a Long-Pulse KrF Laser

The hydrodynamics of plasma formed in the interaction of 100 ns UV KrF laser pulses with foam targets with volume densities from 5 to 500 mg/cm3 was studied. Initial and dynamic transmittance at 248 nm wavelength were measured. At intensities of about 1012 W/cm2, the propagation rates of radiation through foam targets reached 80 km/s, while plasma stream velocities from both the front and rear sides of targets were approximately the same, ~ 75 km/s, which confirms a volumetric absorption of radiation within the target thickness and the explosive nature of the plasma formation and expansion