The requested instrument is a high-energy broadly tunable nanosecond-pulsed laser manufactured by Opotek LLC. This instrument will serve as an excitation source for a wide array of nanosecond time-resolved transient spectroscopies (luminescence, UV-Visible absorption, FTIR, resonance Raman) as well as an excitation source for steady-state Raman spectroscopy. The laser will be housed in the Beckman Institute Laser Resource Center, a facility focused on providing the Caltech research community with instrumentation and guidance in steady-state and time-resolved laser spectroscopy, conventional spectroscopy, photophysics, and photochemistry. A primary focus of the Center is time-resolved spectroscopy for measurements of chemical and biochemical kinetics, and the elucidation of chemical reaction mechanisms. The laser will furnish essential support for three NIH-funded research programs of Major Users, as well as three externally funded and three internally funded research programs of Other Users. The NIH-funded programs include: studies of radical transfer pathways in iron and copper oxygenases and oxidases; elucidation of the photochemical mechanisms of copper-based catalysts involved in (enantioselective) C–N bond formation; mechanistic investigations of dinitrogen reduction chemistry catalyzed by bioinspired iron model complexes; and investigations of DNA mediated charge transfer processes in Pseudomonas aeruginosa biofilms. Other research projects utilizing the instrument will address: mechanistic investigations of lytic polysaccharide monooxygenase catalysis; photophysical investigations of arylisocyanide-metal complexes; development of table-top plasma sources for soft to hard x- rays; time-resolved spectroscopic characterization of photoredox mechanisms; and time- resolved spectroscopic characterization of bipentacene triplet states generated via singlet fission.