Two-photon Raman processes in spectral ultrabroadening of intense ultrashort light pulses

Two-photon Raman-type self-induced transparency for few-cycle laser pulses

“…These properties are an instantaneous intensity-dependent cross section, continuous frequency-modulating and pulse reshaping. It has been shown that the 2π pulse RSIT in conditions of stimulated Raman self-scattering (SRSS)permit to generate a spectral supercontinuum [17][18][19][20]. First a breakup of a few-cycle 4π pulse into two 2π pulse was observed in our simulation on SRSS [21] with pulses containing three and four optical cycles (full width at half maximum (FWHM)).…”

“…We will consider the propagation of a laser pulse with duration τ which satisfies the condition SRSS [16][17][18][19][20][21][22]…”

High intense single attosecond pulses with photon energy up to EUV

“…Continuous Stokes frequency shift with spectral broadening of femtosecond pulses under the condition of SRSS, in vibrational transitions, was experimentally observed in different media [14], when initial laser pulse duration τ o was below 100 fs. In [13,15] it was shown theoretically that under the condition of SRSS the continuous spectral broadening to Stokes direction occurred when the two-photon Rabi frequency Ω (2) , that corresponded to this stimulated Raman process, was less π/τ o . But for pulses with more intensity, when the two-photon Rabi frequency was more π/τ o (especially ∼ 2π/τ o ), the superbroadening to both anti-Stokes and Stokes direction, and the generation of spectral supercontinuum occurred [13,15].…”

“…In [13,15] it was shown theoretically that under the condition of SRSS the continuous spectral broadening to Stokes direction occurred when the two-photon Rabi frequency Ω (2) , that corresponded to this stimulated Raman process, was less π/τ o . But for pulses with more intensity, when the two-photon Rabi frequency was more π/τ o (especially ∼ 2π/τ o ), the superbroadening to both anti-Stokes and Stokes direction, and the generation of spectral supercontinuum occurred [13,15]. In addition, for some conditions a two-photon self-induced transparency (SIT) at SRSS for few-cycle laser pulses had been predicted and an equation for the change in the total energy had been derived [16].…”

Single and double attosecond pulses: resonance generation and propagation in Ar+

“…For further consideration, it is convenient to introduce an angle of rotation of material variable [17][18][19]:…”