This award supports the upgrade of instrumentation used in the research area of dynamics of solid state systems. Fundamental problems in dynamics and intermolecular interactions in solids are currently studied. Specifically, dynamics in low temperature glasses probed with time domain and frequency domain optical nonlinear experiments, the mechanism of superconductivity in the new high temperature superconducting materials, and polariton dynamics in molecular single crystals at very low temperatures probed with transient grating experiments will be studied with the proposed instrumentation. The requested equipment includes a mode-locked YAG laser with frequency doubler and Q-switch, two dye lasers, two Pockel cells, 4 doublers, 2 amplifiers for the dye lasers, associated hardware, optics, electronics and an optical bench.