Femtosecond continua produced in gases

Femtosecond filamentation in transparent media

“…Among the mechanisms that have been proposed to explain the white light continuum generation, there are self-phase modulation (SPM) (Fork et al, 1983;Yang and Shen, 1984), ionization-enhanced SPM (Fork et al, 1983;Corkum et al, 1986), with additional contributions from the interplay of diffraction and instantaneous electronic Kerr nonlinearity (Manassah et al, 1988), stimulated Raman scattering, temporal self-steepening, and four-wave parametric processes (Penzkofer et al, 1975;Yang and Shen, 1984;Corkum and Rolland, 1989;Chin et al, 1999a, b;Brodeur and Chin, 1999;Gaeta, , 2002Aközbek et al, 2001;Fang and Kobayashi, 2003). However, a definitive understanding of the rich physics involved in SCG is still missing (Schumacher, 2002).…”

Coherent control using adaptive learning algorithms

“…These modulations are typical spectral features for pulses that have undergone SPM [25]. The learning algorithm is able to control their frequency and phase by altering the shape of the driving pulse.…”

Optical spectral broadening and supercontinuum generation in telecom applications

“…When the pump power is greater or about 10 TW/cm 2 , which can be reached in light filaments, free-electron plasma formation can also occur, further strengthening the effect of SPM [58]. One of the primary inherent disadvantages of CG schemes based on bulk media (also including those based on liquids [59,60] and gases [61][62][63] as nonlinear media) is the requirement of high pump powers. Typical level of power density required is around several terawatts per cm 2 , thus necessitating additional amplification of laser pulses at the risk of sample damage.…”