The stable, femtosecond mid-IR probe beams are used to measure small changes (ΔA ca
) in sample absorption following photo-excitation of electronic or vibrational transitions in molecules.
The Ultra TRIR station has 2 x 128 pixels (probe) and 1 x 64 element (reference) mercury cadmium telluride (MCT) array detectors from IR Associates and Infrared Development Systems that measure the single shot IR spectra over a 500 cm-1 spectral window and 850 to 5000 cm-1 range. The MCT arrays connect to high speed 512 channel 10 kHz readout DAQs.
Time-resolved infrared spectrum of phenylbenzophenone triplet state formation in CD3OD solvent. Positive peaks are transient species formed on excitation to the triplet-state. Negative peaks are the bleaches of the ground state infrared spectrum upon excitation.