Phase pulling in transient Raman amplifers

Picosecond pulse generation in a benzene raman generator amplifier system

“…Behind the final Raman amplifier the frequencytime bandwidth product of the Raman signals has become smaller than that of the pump laser indicating some temporal-spectral beam clean-up effect in the Raman amplifiers [37,[48][49][50].…”

“…This wavefront preservation has gained importance in the generation of nearly diffraction limited Raman amplified pulses with aberrated pump lasers and multi-beam pump sources (beam clean-up [28, 39^13] and beam combination [44][45][46][47] of lasers, mainly excimer lasers). Under transient Raman amplification conditions phase pulling effects have been observed (amplified Raman signal takes over the phase relation of the pump laser) [37,[48][49][50]. In a recent paper we studied the stimulated Raman scattering of benzene in a generator cell [51].…”

Transient Stimulated Raman Scattering

“…It has long been known that (1.1) has a Lax pair when /-0 and so has soliton solutions [2]. On the other hand, we note that it is physically reasonable to require that (1.2) Z(T) surprisingly, soliton-like pulses are not observed in experiments with laser beams whose durations are short compared to the molecular de-excitation time [4], [5] even though setting -y 0 is presumably "more legitimate" for the latter case. Indeed, numerical experiments indicate that both u and z tend toward zero almost everywhere as --+ oo for a fairly broad set of initial data [13], [7]; compare 5.…”