Blue-shifted third-harmonic generation and correlated self-guiding during ultrafast barrier suppression ionization of subatmospheric density noble gases

Observation of Phase-Matched Relativistic Harmonic Generation

“…The broad blueshifted component is consistent with the third harmonic generated from ionization [14], because it disappears when the gas is preionized and the broadening and blueshifting are consistent with ionization [8,15]. We believe that the narrow unshifted component is the third harmonic produced from relativistic harmonic generation because its spectrum is narrow (about 1͞3 of the bandwidth of the pump pulse) and unshifted and its spectrum FIG.…”

Filamentation of high-power femtosecond laser radiation

“…The relation between the spectral intensity of the shortwavelength components of the spectrum with their spectral distribution was established for the blue wing of a supercontinuum in [141] for picosecond and femtosecond radiation at 600 nm and in [142] for the third harmonic of femtosecond radiation (80 fs) at 800 nm propagating in inert gases. Experiments on élamentation in water and heavy water with 1.06-mm, 22-ps, 35-mJ laser pulses showed that the divergence of the spectral components of a supercontinuum in the anti-Stokes region is independent of the geometrical focusing distance of radiation and increases with their shift to the blue [143].…”

Short-Pulse Laser-Produced Plasmas

“…Analysis of the spectrum of the specular backscattered laser have been used to monitor the critical surface expansion [39][40][41]. Similar experiments have been performed in gases [42][43][44] and clusters [45]. A more efficient method to probe the plasma expansion relies on the spectral analysis of a reflected auxiliary beam at different delays.…”