High-power forward Raman amplifiers employing low-pressure gases in light guides II Experiments

Picosecond pulse generation in a benzene raman generator amplifier system

“…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].…”

Diamond‐based concept for combining beams at very high average powers

“…The Raman linewidth of the high pressure gases used were typically much less than 1 cm −1 and narrower than most free‐running pump lasers, making it necessary to pay attention to the coherence of the Raman interaction in order to achieve adequate power transfer and avoid beam quality degradation of the Stokes output. This problem was addressed by either actively narrowing the pump linewidth or by synchronizing phase correlations in each interacting beam . A further complication was that the scheme was not readily adaptable to high average power systems due to the relatively poor thermal conductivity of gases and the resulting accumulation of heat from the inelastic scattering intrinsic to the Raman process.…”

High‐efficiency stimulated Raman scattering from alcohols: theory and experiments

“…3 Because of its very large gain coefficient, the vibrational transition of gases such as H 2 at a pressure of several atmospheres and a temperature of ¾300 K has been an attractive candidate for the efficient Raman conversion of a laser to a Stokes wavenumber shift. 4,5 Other liquid substance has been tested in SRS, such as water. 6 In this case, high efficiency (¾13%) has been reported.…”