Modulation instability induced by cross-phase modulation of transient stimulated Raman scattering and self-phase modulation in calcite

Pairs of sidebands about the transient stimulated Raman scattering (SRS) 1086 c m − 1 vibration mode peak are observed for calcite under 517 nm 390 fs pulse excitation. These pairs of side frequency lobes arise from modulation instability (MI) from the interaction of cross-phase modulation (XPM) from self-phase modulation (SPM) and SRS. The pairs of secondary frequencies are attributed to the daughter 1086 c m − 1 decay product modes from the multiphonon of 3, 4, and 5 decays. The main sideband peak from 1086 c m − 1 phonon at 546 c m − 1 suggests the operation of the Orbach effect.