Interaction-induced Raman scattering from fused silica

Fused silica displays an interaction-induced (I-I) Raman baseline intensity which decreases nonlinearly under the «main-phonon» intensity from ≤8 to ≃2000 cm -1 . This I-I scattering is an important new measure of disorder. For example, the X(ZX)Y and X(ZZ)Y I-I baselines from fused silica at 8 cm -1 are ≃5 and ≃2 times more intense, respectively, than those from α-quartz. Also, the I-I time-correlation function, C(t), decreases from 1 to 0.01 in ≃2 ps for fused silica, and times at which C(t) decreases to 0.01, for four materials, decrease with decreasing disorder, as follows: (4) water (25 o C); (3) fused silica; (2) ice; and, (1) quartz