Femtosecond Pump-Probe Spectrometer
Femtosecond transient absorption spectroscopy allows us to measure processes that occur on the picosecond timescale. Examples of these processes are: excited state energy transfer, inter- and intramolecular electron transfer reactions, charge transfer complexation and radical recombination in aqueous and nonaqueous solvents as well as in heterogeneous systems such as colloidal suspensions and thin films. This spectroscopic method allows us to simultaneously record kinetic and spectral data regarding the excited state decay of our materials of interest. Pump wavelengths are tunable (230-1600 nm) but most intense at the fundamental (775 nm) and multiples of this 150 fs pulse. Use of a chopper and a delay stage allow measurements out to about 2 ns and a pair of detectors probe the wavelength regions 200-1000 nm and 800-1600 nm respectively.