Amplification of ultrashort phase-modulated laser pulses in media with a discrete spectrum

A theory of the amplification of phase-modulated ultrashort laser pulses is developed for media having a discrete and approximately equidistant gain band structure. It is shown that fundamentally new propagation regimes are feasible in this case. Depending on the parameters of an input pulse, trains of ultrashort pulses of fixed period or having a period governed by the phase modulation of the input pulse may be formed as a result of the amplification. A general method is proposed for the study of the propagation of phase-modulated pulses in media having an arbitrary gain band structure. It is also shown that phase modulation of an input pulse may increase appreciably the energy of the amplified pulses.