GROWTH FROM SPONTANEOUS EMISSION IN A RAMAN MULTIPASS CELL

Previous investigations of stimulated Raman scattering in a multipass cell have considered the amplification of a Stokes input pulse. They f ound that a simple plane-wave transient theory, appropriately scaled t o include the multiple passes and focusing, matched experimental data well. In this paper, we investigate growth from spontaneous emission i n a H-2 Raman multipass cell. We find that a fully-quantum-mechanical scaled plane-wave theory describes the growth from spontaneous emissio n well in the high-gain limit. However, in the low-gain regime there i s a significant increase in the Stokes output which is not predicted b y the scaled plane-wave theory.